Antibacterial intracanalicular insert

Abstract

In certain embodiments, the present invention relates to a sustained release biodegradable intracanalicular insert containing besifloxacin dispersed in a hydrogel for the treatment of ocular infections. According to certain embodiments of the present invention, ocular infections are treated by administering the biodegradable insert to the upper and / or lower canaliculus of the eye. The insert provides a sustained release of an antibiotic, such as besifloxacin, that is effective in treating ocular infections in patients with only a single administration, without the need for removal of the drug-depleted insert, for a period of, for example, one week or more.

Description

[Technical field]

[0001] The present invention relates to the treatment of ocular infections. According to certain embodiments of the present invention, ocular infections are treated by administering a biodegradable insert to the upper and / or lower canaliculus of the eye, the insert providing a sustained release of besifloxacin. [Background technology]

[0002] Ocular infections are a common eye condition. They can be serious as they can lead to reduced eye function and blindness. Currently, a huge number of patients visiting eye clinics are diagnosed with ocular infections, making them a major public health problem.

[0003] Ocular infections are commonly treated with antibiotic eye drops. Problems inherent in the formulation of currently available eye drops. Eye drops may have to be administered several times per day, as most of the active ingredient is quickly washed out of the eye, and therefore the exposure of the ocular surface to the active drug may be short. For this reason, formulations often maximize the concentration to compensate for this inefficiency, which may be associated with a sudden high concentration at the ocular surface, which may cause safety issues. In addition, burning, itching, and stinging pain associated with preservatives, such as antibacterial preservatives, contained in eye drops may be observed. Furthermore, if a patient needs to administer eye drops multiple times a day, this may have a significant impact on daily life and reduce patient compliance. The accuracy of delivery of eye drops to the ocular surface may also be limited, as administering eye drops into the eye may be difficult. Thus, over- or under-dosing may occur.

[0004] Considering the shortcomings and challenges of currently available treatments, novel treatment methods that effectively deliver antibiotics at appropriate doses and are effective in treating ocular infections for extended periods of time, such as for a week or more, while avoiding the need for daily antibiotic administration, would provide benefit to patients. Summary of the Invention

[0005] It is an object of certain embodiments of the present invention to provide an ocular insert containing an antibiotic, such as besifloxacin, that is effective in treating an ocular infection in a patient for a period of one week or more.

[0006] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of the antibiotic to the ocular surface via the tear fluid.

[0007] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of the antibiotic via the tears to the ocular surface, wherein the sustained release period comprises a period of constant or substantially constant antibiotic release per day.

[0008] Another object of certain embodiments of the present invention is to provide an ocular insert containing an antibiotic, such as besifloxacin, that provides treatment for ocular infections for one week or more with only a single dose.

[0009] Another object of certain embodiments of the present invention is to provide an ocular insert containing an antibiotic, such as besifloxacin, that is sufficiently biodegradable, thereby avoiding the need to remove the drug-depleted insert.

[0010] Another object of certain embodiments of the present invention is to provide an ocular insert containing an antibiotic, such as besifloxacin, which is biocompatible and has low or no immunogenicity due to the insert of certain embodiments containing no animal or human derived components.

[0011] It is another object of certain embodiments of the present invention to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that is free of antimicrobial preservatives.

[0012] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that is dimensionally stable in a dry state, but that undergoes dimensional changes upon moisture absorption, for example, after administration to the eye.

[0013] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that is administered dry and absorbs moisture when inserted (e.g., into the lacrimal canaliculus).

[0014] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that, in a dry state, is easy to administer, yet is firmly fixed within the lacrimal canaliculus, avoiding potential loss of the insert during the treatment period, thereby providing improved retention compared to commonly applied plugs (e.g., collagen or silicone plugs).

[0015] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, where the insert is stable and has a defined shape and surface area both before and after insertion (i.e., within the canaliculus).

[0016] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that is easy to handle, particularly one that is not prone to spilling or crumbling.

[0017] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that allows for precise administration of a dose (within a wide dose range), thereby avoiding the risks of overdosing and underdosing.

[0018] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that does not cause antibiotic peaks or potentially substantial peaks that could have adverse effects.

[0019] Another object of certain embodiments of the present invention is to provide an ophthalmic insert comprising an antibiotic, such as besifloxacin, for the treatment of ocular infections (e.g., acute treatment of ocular infections) that has a lower incidence of side effects, such as burning, stinging, or itching, as compared to commonly known treatments for ocular infections.

[0020] Another object of certain embodiments of the present invention is to provide an ocular insert containing an antibiotic, such as besifloxacin, that offers patients a hands-free alternative compared to traditional treatments for eye infections.

[0021] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that remains in the area of ​​the eye to which it is administered, such as the inferior and / or superior canaliculus (vertical portion).

[0022] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that improves patient compliance compared to currently available treatments for ocular infections.

[0023] Another object of certain embodiments of the present invention is to provide an ocular insert containing an antibiotic, such as besifloxacin, that can be visualized in a rapid and simple manner and by non-invasive methods.

[0024] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of a therapeutically effective amount of the antibiotic (e.g., besifloxacin) for an extended period of time, such as up to about 7 days, up to about 14 days, or up to about 21 days, or up to about 30 days, or up to 42 days, after administration.

[0025] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that releases a constant or essentially constant amount of antibiotic, such as besifloxacin, over an extended period of time after administration, for example, up to about 7 days, or up to about 14 days, or up to about 21 days, or up to about 30 days, or up to about 42 days.

[0026] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of a therapeutically effective amount of an antibiotic, such as besifloxacin, for an extended period of time after administration (e.g., up to about 7 days, up to about 14 days, or up to about 21 days, or up to about 30 days, or up to about 42 days), thereby avoiding the need for frequent administration of the antibiotic, e.g., several times a day, as required when using eye drops.

[0027] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of a therapeutically effective amount of an antibiotic, such as besifloxacin, for an extended period of time after administration, for example, up to about 7 days, up to about 14 days, or up to about 21 days, or up to about 30 days, or up to about 42 days, such that the amount of antibiotic in the tear film is consistently maintained at a therapeutically effective level sufficient for anti-inflammatory therapy of the ocular surface.

[0028] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of a therapeutically effective amount of an antibiotic, such as besifloxacin, for an extended period of time after administration, e.g., up to about 7 days, up to about 14 days, or up to about 21 days, or up to about 30 days, or up to about 42 days, and where essentially no toxic concentrations of the antibiotic are observed on the ocular surface and / or in the tear film.

[0029] Another object of certain embodiments of the present invention is to provide an ophthalmic insert containing an antibiotic, such as besifloxacin, that provides sustained release of a therapeutically effective amount of an antibiotic, such as besifloxacin, for an extended period of time after administration, for example, up to about 7 days, up to about 14 days, or up to about 21 days, or up to about 30 days, or up to about 42 days, and wherein the antibiotic is not systemically reabsorbed or is not substantially systemically reabsorbed, thereby minimizing or avoiding systemic toxicity.

[0030] Another object of certain embodiments of the present invention is to provide a method of treating an eye infection in a patient in need thereof with the ocular inserts disclosed herein.

[0031] Another object of certain embodiments of the present invention is to provide a method of manufacturing an ophthalmic insert that contains an antibiotic, such as besifloxacin.

[0032] One or more of these and other objects of the present invention are addressed by one or more embodiments of the invention disclosed and claimed herein. [Brief description of the drawings]

[0033] [Figure 1] 1 is a schematic diagram of an exemplary insert package: The insert is placed in a foam carrier and sealed in a foil pouch. [Diagram 2] Schematic example of placement of an insert into the eye from the inferior punctum to the vertical portion of the inferior canaliculus (A). Visualization of the insert is possible, for example, by illumination with blue light (B). In one embodiment, fluorescein in the intracanalicular insert fluoresces when excited with blue light, allowing the presence of the insert to be confirmed in a non-invasive manner. [Diagram 3] 1 shows the pharmacokinetic profile of besifloxacin tears in beagle dogs. [Figure 4] 1 shows the mean besifloxacin in tears versus time in beagle dogs.

[0034] definition The term "insert" as used herein refers to an object that contains an active agent, particularly an antibiotic such as besifloxacin, and is administered to the human or animal body, e.g., to the lacrimal canaliculi of the eye (one or both eyes, as well as the lower and / or upper canaliculi), and remains there for a period of time while releasing the active agent to the surrounding environment. The insert may have any predefined shape before it is inserted, and its general shape may be maintained to some extent once the insert is placed in the desired location, but the dimensions of the insert (e.g., length and / or diameter) may change after administration due to moisture absorption, as further disclosed herein. In other words, what is administered to the lacrimal canaliculi of the eye is not a solution and suspension, but a conformable object that is already formed. Thus, the insert is fully formed, e.g., according to the methods disclosed herein, before it is administered. Over time, the insert inserted in certain embodiments may biodegrade (as disclosed herein), thereby changing its shape (e.g., expanding in diameter and decreasing in length) until it is completely dissolved / resorbed. The term "insert" is used herein to refer to both the insert in a hydrated (also referred to herein as "wet") state when it contains water (e.g., after the insert has hydrated or rehydrated when administered to the eye or otherwise immersed in an aqueous environment (e.g., in vitro)) and the insert in a dry (dry / dehydrated) state. Thus, in certain embodiments, the insert in a dry / dry state in the context of the present invention may contain about 1% water by weight or less. The water content of the insert in a dry / dehydrated state may be measured, for example, by Karl Fischer coulometry. Whenever dimensions (i.e., length, diameter, or volume) of the insert in a hydrated state are reported herein, these dimensions are measured after the insert is immersed in phosphate buffered saline at 37° C. and pH value 7.4 for 24 hours. When dimensions of the insert are reported herein in a dry state, these dimensions are measured after the insert has completely dried (and thus, in certain embodiments, contains about 1% water by weight or less). In a particular embodiment, the inserts are stored in an inert atmosphere glove box containing less than 20 ppm of both oxygen and moisture for at least about 7 days.

[0035] In certain embodiments of the invention, the term "fiber" (used interchangeably herein with the term "rod") characterizes an object (i.e., in this case, an insert according to certain embodiments of the invention) having a generally elongated shape. Specific dimensions of the inserts of the invention are disclosed herein. The inserts may have a cylindrical or essentially cylindrical shape, or a non-cylindrical shape. The cross-sectional area of ​​the fiber or insert may be circular or essentially circular, but may also be oval or rectangular in certain embodiments, and in other embodiments may have different shapes, such as a cross, a star, or other shapes disclosed herein.

[0036] The term "ocular" as used herein refers to the eye in general, or any part or site of the eye (such that an "ocular insert" according to the present invention refers, in principle, to an insert that can be administered to any part or site of the eye). In certain embodiments, the present invention relates to intracanalicular administration of an ocular insert (in which case the "ocular insert" is an "intracanacanalicular insert") and the treatment of eye infections.

[0037] The term "biodegradable" as used herein refers to a material or object (e.g., an intracanalicular insert according to the present invention) that becomes degraded when placed in vivo, i.e., in the human or animal body. In the context of the present invention, as disclosed in detail herein, an insert comprising a hydrogel having dispersed therein antibiotic particles, such as besifloxacin particles, gradually biodegrades over time when deposited in the eye, e.g., in the lacrimal canaliculus. In certain embodiments, biodegradation occurs at least in part via ester hydrolysis in the aqueous environment provided by tears. In certain embodiments, the intracanalicular insert of the present invention gradually softens and liquefies, and is eventually cleared (excreted / flows out) through the nasolacrimal duct.

[0038] A "hydrogel" is a three-dimensional network of one or more hydrophilic natural or synthetic polymers (disclosed herein) that can swell in water and retain a certain amount of water while maintaining or substantially maintaining its structure, e.g., by chemical or physical crosslinking of individual polymer chains. Due to the high water content, hydrogels are soft and flexible, and thus closely resemble natural tissue. In the present invention, the term "hydrogel" is used to refer to both hydrogels in a hydrated state (also referred to interchangeably herein as a "wet state") when they contain water (e.g., after the hydrogel is formed in an aqueous solution, or after the hydrogel is hydrated or rehydrated when inserted into the eye or otherwise immersed in an aqueous environment), and hydrogels in a dry (dried / dehydrated) state when they are dried to a low water content of, e.g., 1% by weight or less, as disclosed herein. In the present invention, when an active ingredient is contained (e.g., dispersed) within the hydrogel, the hydrogel may also be referred to as a "matrix."

[0039] The term "polymer network" as used herein describes a structure formed from polymer chains (of the same or different molecular structure and of the same or different average molecular weight) that are crosslinked to each other. Types of polymers suitable for the purposes of the present invention are disclosed herein. The polymer network may be formed using crosslinking agents, also disclosed herein.

[0040] The term "amorphous" refers to a polymer or polymer network or other chemical substance or entity that does not exhibit a crystalline structure in an X-ray or electron scattering experiment.

[0041] The term "semi-crystalline" refers to a polymer or polymer network, or other chemical substance or entity, that has some crystalline properties, i.e., exhibits some crystalline properties in X-ray or electron scattering experiments.

[0042] The term "crystalline" refers to a polymer or polymer network, or other chemical entity, that has crystalline properties as evidenced by X-ray or electron scattering experiments. The terms "precursor" or "polymer precursor" or, in particular, "PEG precursor" herein refer to molecules or compounds that react with one another and thereby become linked through crosslinks to form a polymer network, and thereby a hydrogel matrix. Other substances, such as active drugs, visualization agents, buffers, etc., may be present in the hydrogel, but are not referred to as "precursors."

[0043] The molecular weight of the polymer precursors used for the purposes of the present invention and disclosed herein can be determined by analytical methods known in the art. For example, the molecular weight of polyethylene glycol can be quantified by any method known in the art, including gel electrophoresis, such as SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis), gel permeation chromatography (GPC) (including GPC with dynamic light scattering (DLS)), liquid chromatography (LC), and mass spectrometry (e.g., matrix-assisted laser desorption / ionization time-of-flight (MALDI-TOF) spectrometry or electrospray ionization (ESI) mass spectrometry). The molecular weight of the polymers comprising the polyethylene glycol precursors disclosed herein is an average molecular weight (based on the molecular weight distribution of the polymer) and therefore can be expressed in various average values, including weight average molecular weight (Mw) and number average molecular weight (Mn). Any such average value can generally be used in the context of the present invention. In the context of the present invention, the average molecular weight of the polyethylene glycol unit or other precursors or units disclosed herein is a number average molecular weight (Mn) and is expressed in "daltons".

[0044] The portions of the precursor molecules that are still present in the final polymer network are also referred to herein as "units." Thus, "units" are the building blocks or constituents of the polymer network that forms the hydrogel. For example, polymer networks suitable for use in the present invention may contain the same or different polyethylene glycol units, as further disclosed herein.

[0045] The term "crosslinker" or "crosslinking agent" as used herein refers to any molecule suitable for linking precursors through crosslinks to form a polymer network, thereby forming a hydrogel matrix. In certain embodiments, the crosslinker may be a low molecular weight compound or a polymeric compound as disclosed herein.

[0046] The term "sustained release" is defined for the purposes of the present invention to generally refer to a pharmaceutical dosage form or product (in the present case, these products are inserts) that is formulated to make the active agent (e.g., an antibiotic according to the present invention, specifically, including but not limited to, besifloxacin) available for an extended period of time (e.g., one week or more) after administration, thereby allowing for reduced dosing frequency compared to immediate release dosage forms, such as an antibiotic solution applied topically to the eye (i.e., eye drops containing antibiotics). Other terms that may be used interchangeably with "sustained release" herein are "sustained release" or "controlled release". Thus, "sustained release" generally characterizes the release of the API (specifically, an antibiotic such as besifloxacin) contained in the insert according to the present invention. The term "sustained release" is not itself associated with or limited to a particular rate of release (in vitro or in vivo), although in certain embodiments of the present invention, the insert may be characterized by a particular average rate of release (in vitro or in vivo), or a particular release profile, as disclosed herein. Because the inserts of the present invention (whether expressly referred to herein as "sustained release" inserts or simply as "inserts") provide for sustained release of an API, the inserts of the present invention may therefore also be referred to as "depots."

[0047] In the present context, the term "sustained release" also includes a period of constant or substantially constant antibiotic release per day (i.e., above a certain level), when the constant or substantially constant release period is followed by a period of tapering antibiotic release. In such a particular case, the overall sustained release provided by the insert of the present invention (as defined above) may mean that the release rate is not necessarily constant or essentially constant throughout the entire period of antibiotic release, but may vary over time (i.e., a constant or essentially constant initial period, i.e., sustained release, followed by a tapering release period), as just explained. In the present context, the term "tapered" or "tapering" refers to the release of an antibiotic, such as besifloxacin, decreasing over time until the antibiotic is completely released.

[0048] The term "visualization agent" as used herein refers to a molecule or composition that may be contained within the insert of the present invention and that provides the possibility of easily visualizing the insert when the insert is located in the lacrimal canaliculus of the eye in a non-invasive manner, for example by illuminating the corresponding eye part with a suitable light source, such as blue light. The visualization agent may be a fluorophore, such as fluorescein, rhodamine, coumarin, and cyanine, or other suitable agent disclosed herein. In certain embodiments, the visualization agent is fluorescein or includes a fluorescein moiety.

[0049] As used herein, the term "ocular surface" includes the conjunctiva and cornea, along with elements such as the lacrimal apparatus (including the lacrimal puncta and lacrimal canaliculi and associated eyelid structures). In the sense of the present invention, the ocular surface also includes the aqueous humor.

[0050] As used herein, the term "tears" or "tear film" refers to the fluid secreted by the lacrimal gland that lubricates the eye. Tears are composed of water, electrolytes, proteins, lipids, and mucin.

[0051] As used herein, the term "bilateral" or "bilateral" (in the context of administration of the inserts of the present invention) refers to administration of the insert to both eyes of a patient. Thus, "unilateral" or "unilateral" refers to administration of the insert to only one eye. The inserts may be inserted independently into the upper and / or lower canaliculi of both or one eye.

[0052] As used herein, terms such as "administration" or "administering" or "administered" in the context of the insert of the present invention refer to the process of inserting the insert into the canaliculus of the eye through the opening of the punctum. Thus, "administering an insert" or similar terms refer to inserting the insert into the canaliculus of the eye. Terms such as "insertion" or "inserting" or "inserted" in the context of the insert of the present invention also refer to the process of inserting the insert into the canaliculus of the eye through the opening of the punctum, and thus are used interchangeably herein with the terms "administration" or "administering" or "administered". In contrast, terms such as "administration" or "administering" or "administered" in the context of topical ophthalmic pharmacological products (not the subject of the present invention), such as eye drops, refer to the topical application of these products to the eye.

[0053] As used herein, the term "insert stacking" or "stacking" refers to inserting a further insert on top of a first insert while the first insert is still retained in the canaliculus (because it has not yet fully biodegraded and / or has not yet been cleared through the nasolacrimal duct). In certain embodiments, the further insert is placed on top of the first insert after the antibiotic contained in the first insert has been completely or essentially completely released, or after at least about 70% or at least about 80% or at least about 90% of the antibiotic contained in the first insert has been released. Insert stacking allows, for example, long-term antibiotic treatment.

[0054] The term "plug" as used herein refers to a device that can provide occlusion, substantial occlusion, or partial occlusion ("duct occlusion") of the tear duct(s), thereby minimizing or preventing tear drainage. Thus, the plug enhances tear retention, which helps keep the eye moist. Plugs can be classified as "punctal plugs" and "intracanalicular plugs." Intracanalicular plugs are also referred to in the literature as "canalicular plugs." Both plug classifications are inserted through the upper and / or lower punctum of the eye. Punctal plugs are placed at the opening of the punctum and are easily visible, thus making them removable without much difficulty. However, punctal plugs can show poor retention and can be easily contaminated by microorganisms due to their exposed localized area that can cause infection. In contrast, intracanalicular plugs are essentially invisible and placed in the vertical or horizontal part of the canaliculus, resulting in higher retention compared to punctal plugs. However, currently available intracanalicular plugs may not be easy to remove and / or may have a loose fit, increasing the risk of migration. Commercially available plugs are often made of collagen, acrylic polymers, or silicone.

[0055] The term "canaliculus" (plural "canaliculi") or "lacrimal duct" as used herein refers to the canaliculi, i.e., the small canaliculi in each eyelid that drains tears (tears) from the lacrimal punctum into the nasolacrimal duct (see also FIG. 2). The canaliculi thus form part of the lacrimal apparatus that drains tears from the ocular surface into the nasal cavity. The canaliculi in the upper eyelid are called the "superior canaliculus" or "upper canaliculus" and the canaliculi in the lower eyelid are called the "inferior canaliculus" or "lower canaliculus". Each canaliculus includes a vertical region that leads to the lacrimal punctum (referred to as the "vertical portion of the canaliculus") and a horizontal region that leads to the vertical portion of the canaliculus (referred to as the "horizontal portion of the canaliculus"), which joins the nasolacrimal duct.

[0056] The term "punctum (plural puncta)" refers to lacrimal punctum, an opening at the edge of the eyelid that corresponds to the entrance of the lacrimal canaliculus. After tears are produced, some liquid evaporates between blinks and some is drained through the punctum. Because puncta are also found on the upper and lower eyelids, they are called "upper punctum" or "superior punctum" and "lower punctum" or "inferior punctum", respectively (see also Figure 2).

[0057] The term "intracanalicular insert" refers to an insert that can be administered into the upper and / or lower canaliculus of the eye (particularly the upper and / or lower canaliculus vertical portion of the eye) through the upper and / or lower punctum. As the insert is localized within the canaliculus, the insert prevents tear drainage through canalicular obstruction (e.g., as also observed with intracanalicular plugs). The intracanalicular insert of the present invention can be inserted into both or either the lower and / or upper canaliculus vertical portion of the eye. According to certain embodiments of the present invention, the intracanalicular insert is a sustained release biodegradable insert.

[0058] The terms "API", "active pharmaceutical ingredient", "active pharmaceutical agent", "active pharmaceutical ingredient", "(active) therapeutic agent", "active drug", and "drug" are used interchangeably herein and refer to substances used in finished pharmaceutical products (FPPs) and substances used in the preparation of such finished pharmaceutical products that provide pharmacological activity or are intended to have a direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to have a direct effect in restoring, correcting, or modifying the physiology of a patient.

[0059] Besifloxacin Drug Substance Besifloxacin is a fourth-generation fluoroquinolone with broad-spectrum activity against aerobic, facultative, and anaerobic Gram-positive and Gram-negative bacteria by inhibiting the bacterial enzymes, bacterial DNA gyrase, and topoisomerase IV. Inhibiting DNA gyrase impairs DNA replication, transcription, and repair. Inhibiting topoisomerase IV impairs decatenation during cell division. Inhibiting these two targets also slows down the development of resistance. In 2009, BESIVANCE® (besifloxacin ophthalmic suspension) 0.6% eye drops was approved for use as a quinolone antibacterial agent indicated for the treatment of bacterial conjunctivitis caused by susceptible isolates (NDA#22308).

[0060] Besifloxacin is approved for the treatment of bacterial conjunctivitis. Isolates susceptible to besifloxacin include: CDC Corynebacterium group G; Corynebacterium pseudodiphtheriticum; Corynebacterium striatum; Haemophilus influenzae; Moraxella lacunata; Staphylococcus aureus; Staphylococcus epidermidis; Staphylococcus hominis; Staphylococcus lugdunensis; Streptococcus mitis group; Streptococcus oralis; Streptococcus pneumoniae; Streptococcus salivarius. Other potential indications include bacterial keratitis, blepharitis, endophthalmitis, or ocular infections caused by bacteria susceptible to killing by besifloxacin.

[0061] The chemical name of besifloxacin (INN / USAN) is (R)-7-(3-aminohexahydro-1H-azepin-1-yl)-8-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid and its CAS number is 141388-76-3.

[0062] The molecular formula and structure is C19H21ClFN3O3. [ka]

[0063] Besifloxacin is a bactericidal fluoroquinolone antibiotic.

[0064] In certain embodiments, for any antibiotic used in the present invention, including besifloxacin, particle sizes (e.g., expressed as d90 values) of about 100 μm or less, or about 75 μm or less, or about 50 μm or less may be used. In certain embodiments of the present invention, besifloxacin may be used in the form of micronized particles, which may have a d90 particle size of about 100 μm or less, or about 75 μm or less, or about 50 μm or less, or about 20 μm or less, or about 10 μm or less, or about 5 μm or less. In these and other embodiments, the d98 particle size of the micronized besifloxacin may be about 100 μm or less, or about 75 μm or less, or about 50 μm or less, or about 20 μm or less, or about 10 μm or less, or about 5 μm or less. In certain embodiments of the present invention, the micronized besifloxacin has a d90 particle size of about 5 μm or less and a d98 particle size of less than about 10 μm. The "d90" value means that at least 90% by volume of all particles in the measured bulk material (having a particular particle size distribution) have a particle size below the indicated value. For example, a d90 particle size less than about 50 μm means that at least 90% by volume of the particles in the measured bulk material have a particle size less than about 50 μm. Corresponding definitions apply to other "d" values, such as the "d98" value. Particle size distribution can be measured by methods known in the art, including sieving, laser diffraction, or dynamic light scattering. In embodiments in which another antibiotic other than besifloxacin is used in the present invention, particle sizes similar to those disclosed for besifloxacin may be applied.

[0065] For the purposes of certain embodiments of the present invention, in addition to meeting certain particle size specifications (e.g., d90 and / or d98 values ​​as disclosed herein) to increase the content uniformity in the final product (thus avoiding too high or too low drug loading by the discrete particles) and / or to reduce the possibility of aggregation of individual API particles during the manufacture of the insert (during the casting of the hydrogel as disclosed herein), it may be beneficial to ensure that there are no or essentially no discrete particles present in the API starting material that are larger than a certain size (e.g., greater than about 120 μm, or greater than about 100 μm, or greater than about 90 μm). This can be achieved, for example, by sieving. In certain embodiments, the besifloxacin used to manufacture the insert according to the present invention has a d90 particle size of about 10 or 5 μm or less and / or a d98 particle size of less than about 10 μm, with all or essentially all discrete particles being less than about 90 μm in size.

[0066] For purposes of the present invention, an active drug (including besifloxacin) may be used in any possible form, including any polymorph of the active drug, or any pharma- ceutically acceptable salt, anhydride, water absorbent, other solvate, or derivative of the active drug. In this description or claims, whenever an active drug is referred to by a name such as "besifloxacin," it also refers to any such pharma- ceutically acceptable polymorph, salt, anhydride, solvate (including water absorbent) or derivative of the active drug, even if not explicitly stated. In particular, the term "besifloxacin" refers to besifloxacin and its pharma- ceutically acceptable salts, all of which may be used for purposes of the present invention. As used herein, the term "polymorph" refers to any crystalline form of an active drug, such as besifloxacin. Often, active drugs that are solid at room temperature exist in a variety of different crystalline forms, i.e., polymorphs, with one polymorph being thermodynamically most stable at a given temperature and pressure.

[0067] As used herein, the term "therapeutically effective" refers to the amount of a drug or active agent (i.e., an antibiotic) required to produce a desired therapeutic response or outcome following administration. For example, in the context of the present invention, one desired therapeutic outcome would be the relief of symptoms associated with an eye infection.

[0068] The term "patient" herein includes both human and animal patients. The inserts according to the invention are generally suitable for human or veterinary medical use. Patients enrolled and treated in clinical trials may also be referred to as "subjects." Generally, a "subject" is an individual (human or animal) to whom an insert according to the invention is administered, for example during a clinical trial. A "patient" is a subject in need of treatment for a particular physiological or pathological condition.

[0069] The term "average" as used herein refers to the central or representative value within a set of data (points), which is calculated by dividing the sum of the data (points) by the number of data (points) in the set (i.e., the average value of the set of data).

[0070] As used herein, the term "about" in connection with a measurand refers to normal variation of the measurand that one of ordinary skill in the art would expect in making the measurement and exercising a level of care commensurate with the purpose of the measurement and the precision of the measurement device.

[0071] As used herein, the term "at least about" in reference to a measurable quantity refers to any amount greater than or equal to the normal variation of the measurable quantity that one of ordinary skill in the art would expect in making the measurement and exercising a level of care commensurate with the purpose of the measurement and the precision of the measurement device.

[0072] As used in this document, the singular forms "a," "an," and "the" include plural referents unless the context clearly indicates otherwise.

[0073] The term "and / or" as used herein in phrases such as "A and / or B" is intended to include both "A and B" as well as "A or B."

[0074] As used herein, open terms such as "comprise," "including," "containing," "including," and the like, mean "including" and are intended to refer to an open-ended list or recitation of elements, method steps, etc., and thus are not intended to be limited to the recited elements, method steps, etc., but are also intended to include additional unrecited elements, method steps, etc.

[0075] The term "up to," when used herein in conjunction with a value or number, is intended to include the respective value or number. For example, the term "up to 25 days" means "up to and including 25 days."

[0076] As used herein, the abbreviation "PBS" means phosphate buffered saline.

[0077] As used herein, the abbreviation "PEG" means polyethylene glycol.

[0078] All references disclosed herein are hereby incorporated by reference in their entirety for all purposes (in the case of conflict, the present specification will control). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] In certain embodiments, the present invention relates to a besifloxacin intracanalicular insert, which is an absorbent hydrogel intracanalicular insert designed for sustained release of besifloxacin, intended for placement in the lacrimal punctum to provide sustained localized delivery of besifloxacin to the ocular surface for the treatment and / or prevention of bacterial ocular infections caused by bacteria susceptible to killing by besifloxacin.

[0080] In certain embodiments, the insert comprises two major components: besifloxacin and a polyethylene glycol (PEG)-based hydrogel conjugated with fluorescein. The fluorescent PEG emits light when excited with a blue light source and assisted by a yellow filter, allowing visualization to confirm the presence of the product. In certain embodiments, besifloxacin is embedded in the fluorescent hydrogel matrix of the insert, for example as micronized besifloxacin base. The dry insert will absorb water upon contact with tears after administration into the canaliculus. This reduces its length and expands its diameter, allowing it to be retained within the canaliculus. The micronized besifloxacin slowly dissolves in the tear fluid, providing sustained release of besifloxacin over the treatment period. Hydrolysis softens and liquefies the insert, allowing it to be cleared through the nasolacrimal duct without the need for removal.

[0081] In certain embodiments, the release rate of the drug is controlled primarily by the solubility of the drug in the hydrogel matrix at the interface of the tear-washing fluid on the exposed cross-sectional area facing the punctal opening. The insert may contain 0.05 mg to 0.8 mg of besifloxacin. Lower doses of besifloxacin are intended to shorten the duration of drug release, while higher doses are intended to lengthen the duration of drug release. This is illustrated in FIG. 3, which shows the difference in the duration of release of besifloxacin drug from the insert as a function of dose.

[0082] In certain embodiments, the hydrogel is entirely synthetic and does not contain any animal or human derived components, hi certain embodiments, the primary component of the hydrogel is PEG, which has a long history of safe use in medical devices, pharmaceuticals, and cosmetics.

[0083] Insert The present invention generally relates to a sustained release biodegradable intraocular insert comprising a hydrogel and an antibiotic, wherein antibiotic particles are dispersed within the hydrogel. In certain embodiments, the insert is for administration into the lacrimal canaliculus of the eye, i.e., an intracanalicular insert.

[0084] In one aspect, the invention relates to a sustained release biodegradable intraocular (e.g., intracanalicular) insert comprising a hydrogel and an antibiotic, wherein antibiotic particles are dispersed within the hydrogel, and the length of the insert in a dry state is less than about 3.0 mm, or about 2.75 mm.

[0085] In another aspect, the invention generally relates to a sustained release biodegradable intraocular (eg, intracanalicular) insert comprising a hydrogel and up to about 800 μg of besifloxacin or an equivalent dose of another antibiotic.

[0086] In another aspect, the invention generally relates to a sustained release biodegradable intraocular (e.g., intracanalicular) insert comprising a hydrogel and an antibiotic, the insert having a length in a dry state (e.g., prior to administration) of about 2.5 mm or less.

[0087] In another aspect, the invention generally relates to a sustained release biodegradable intraocular (e.g., intracanalicular) insert comprising a hydrogel and an antibiotic, wherein the insert provides release of a therapeutically effective amount of the antibiotic for up to about 42 days after administration.

[0088] In all these aspects, the particular antibiotic used in the present invention is besifloxacin.

[0089] In all these aspects, the ocular insert in certain embodiments of the invention may be an intracanalicular insert, i.e., the insert is for insertion / administration into the lacrimal canaliculus of one or both eyes.

[0090] Each of the features listed above in the three embodiments of the present invention may be present separately in the sustained release biodegradable insert of the present invention, or any two of these features may be present in combination, or all three of these features may be present in combination.

[0091] Thus, in one particular embodiment, the present invention relates to a sustained release biodegradable intracanalicular insert comprising a hydrogel and besifloxacin as an antibiotic, the insert containing about 800 μg or less of besifloxacin, having a length of about 2.75 mm or less, and providing release of a therapeutically effective amount of besifloxacin for up to about 42 days after administration.

[0092] Specific embodiments and features of the insert of the present invention are disclosed below.

[0093] Active ingredients The present invention, in certain embodiments, generally relates to sustained release biodegradable intraocular (e.g., intracanalicular) inserts comprising a hydrogel and an antibiotic. One particular antibiotic used in all aspects of the invention is besifloxacin. Details regarding besifloxacin, its chemical structure, and properties such as solubility are disclosed in the definitions section herein.

[0094] In certain embodiments of the invention, the antibiotic contained in the sustained release biodegradable intraocular (e.g., intracanalicular) insert is besifloxacin and is present in the insert in a dosage range of about 10 μg to about 800 μg, or about 50 μg to about 600 μg. Any amount of besifloxacin within these dosage ranges may be used, e.g., about 50 μg, about 100 μg, about 150 μg, about 400 μg, about 450 μg, about 500 μg, about 600 μg, etc., all values ​​including a variation of +25% to -20%, or ±10%. In certain embodiments, the dosage of besifloxacin contained in the insert of the invention is as follows:

[0095] The disclosed amounts of antibiotics such as besifloxacin (including the variances noted above) refer to both the final content of the active ingredient in the insert and the amount of active ingredient used as a starting component in the manufacture of the insert.

[0096] In certain embodiments, an antibiotic such as besifloxacin may be included in the insert of the present invention such that the antibiotic particles are dispersed or distributed within the hydrogel of the polymer network. In certain embodiments, the particles are uniformly dispersed within the hydrogel. The hydrogel may prevent the drug particles from agglomerating and may provide a matrix for the particles that releases the drug in a sustained manner upon contact with tear fluid.

[0097] In certain embodiments of the present invention, antibiotic particles, such as besifloxacin particles, may be microencapsulated. The term "microcapsule" is often defined as a roughly spherical particle having a size that varies, for example, from about 50 nm to about 2 mm. A microcapsule has at least one discrete domain (or core) of active agent that is encapsulated in a surrounding or partially surrounding material (also called a shell). For the purposes of the present invention, a suitable agent for microencapsulating antibiotics, such as besifloxacin, is poly(lactic-co-glycolic acid).

[0098] In one embodiment, the antibiotic particles, such as besifloxacin particles, may be small in size and may be micronized particles. In another embodiment, the antibiotic particles, such as besifloxacin particles, may be micronized. Micronization refers to the process of reducing the average diameter of the particles of a solid material. Small diameter particles may, among other things, have a higher dissolution rate, which improves the bioavailability of the pharmaceutical ingredient. In the field of composite materials, particle size is known to affect the mechanical properties when combined with a matrix, with smaller particles providing better reinforcement for a given mass fraction. Thus, a hydrogel matrix in which micronized antibiotic particles are dispersed may have improved mechanical properties (e.g., brittleness, strain to failure, etc.) compared to larger antibiotic particles of a similar mass fraction. Such properties are important in the manufacture of the insert, during administration, and during degradation. Micronization may also promote a more uniform distribution of the active ingredient within a selected dosage form or matrix. In certain embodiments, for any antibiotic used in the present invention, including besifloxacin, a particle size (e.g., expressed as a d90 value as defined herein and measured as disclosed herein) of about 100 μm or less, or about 75 μm or less, or about 50 μm or less may be used. In certain embodiments, besifloxacin may be used in the form of micronized particles, which may have a d90 particle size of about 100 μm or less, or about 75 μm or less, or about 50 μm or less, or about 20 μm or less, or about 10 μm or less, or about 5 μm or less. In these and other embodiments, the d98 particle size of micronized besifloxacin may be about 100 μm or less, or about 75 μm or less, or about 50 μm or less, or about 20 μm or less, or about 10 μm or less, or about 5 μm or less. In certain embodiments of the invention, the micronized besifloxacin used (or used to prepare) the inserts of the invention has a d90 particle size of about 5 μm or less and a d98 particle size of less than about 10 μm. In embodiments in which another antibiotic other than besifloxacin is used in the invention, particle sizes similar to those disclosed for besifloxacin may be applied.

[0099] In certain embodiments, to reduce the presence of discrete particles within the starting antibiotic (particularly besifloxacin) that are larger than a certain size (e.g., greater than about 120 μm, or greater than about 100 μm, or greater than about 90 μm), the bulk antibiotic that meets the particle size specification(s) (d90 and / or d98) disclosed herein may be sieved prior to preparing the wet composition of the insert. In certain embodiments, the besifloxacin used to manufacture the insert according to the present invention has a d90 particle size of about 5 μm or less and a d98 particle size of less than about 10 μm, with all or essentially all discrete particles less than about 90 μm in size.

[0100] Polymer Network In certain embodiments, hydrogels may be formed from precursors that have functional groups that form crosslinks to form a polymer network. These crosslinks between the polymer chains or arms may be chemical (i.e., may be covalent) and / or physical (e.g., ionic bonds, hydrophobic bonds, hydrogen bridges, etc.) in nature.

[0101] The polymer network can be prepared from either one type of precursor or two or more types of precursors that can react. The precursor is selected with consideration of the properties desired for the resulting hydrogel. There are a variety of suitable precursors for use in the creation of hydrogels. In general, any pharma- ceutically acceptable crosslinkable polymer that forms a hydrogel can be used for the purposes of the present invention. The hydrogel and the components incorporated therein (e.g., the polymers used to create the polymer network) should be physiologically safe, e.g., not eliciting an immune response or a substantial immune response or other adverse effects. The hydrogel can be formed from natural, synthetic, or biosynthetic polymers.

[0102] Natural polymers may include glycosaminoglycans, polysaccharides (eg, dextran), polyamino acids, and proteins, or mixtures or combinations thereof, although this list is not intended to be limiting.

[0103] Synthetic polymers may generally be any polymers synthetically produced from a variety of raw materials by various types of polymerization (e.g., free radical polymerization, anionic or cationic polymerization, chain growth or addition polymerization, condensation polymerization, ring-opening polymerization, etc.). Polymerization may be initiated by specific initiators, light and / or heat, and may be mediated by catalysts. Synthetic polymers may be used in certain embodiments to reduce the allergenic potential in dosage forms that do not contain any components of human or animal origin.

[0104] Generally, for the purposes of the present invention, one or more synthetic polymers from the group comprising one or more polyalkylene glycol units (particularly including, but not limited to, polyethylene glycol (PEG), polyalkylene oxides such as polyethylene oxide, polypropylene oxide, polyvinyl alcohol, poly(vinylpyrrolidone), polylactic acid, polylactic-co-glycolic acid, random or block copolymers, or any combination / mixtures thereof) can be used, although this list is not intended to be limiting.

[0105] To form a covalently crosslinked polymer network, the precursors can be covalently crosslinked to one another. In certain embodiments, precursors having at least two reactive centers (e.g., in free radical polymerization) can function as crosslinkers, since each reactive group can participate in the formation of a different growing polymer chain.

[0106] The precursors may have biologically inert and hydrophilic portions, such as the core. In the case of branched polymers, the core refers to the continuous portion of the molecule connected to arms extending from the core, where the arms often have functional groups at the ends of the arms or branches. Multi-arm PEG precursors are examples of such precursors and are used in certain embodiments of the invention, as further disclosed herein.

[0107] The hydrogels used in the present invention can be made, for example, from one multi-arm precursor having a (set of) first functional group(s) and another (e.g., multi-arm) precursor having a (set of) second functional group(s). By way of example, the multi-arm precursor may have hydrophilic arms (e.g., polyethylene glycol units) terminated with primary amines (nucleophiles) or may have activated ester end groups (electrophiles). The polymer network according to the present invention may comprise identical or different polymer units crosslinked to each other. The precursors may be high molecular weight building blocks (e.g., polymers with functional groups as further disclosed herein) or low molecular weight building blocks (e.g., small amines, thiols, esters, etc., also as further disclosed herein).

[0108] Certain functional groups can be made more reactive by using activating groups. Such activating groups include, but are not limited to, carbonyldiimidazole, sulfonyl chloride, aryl halide, sulfosuccinimidyl ester, N-hydroxysuccinimidyl (abbreviated as "NHS") ester, succinimidyl ester, benzotriazolyl ester, thioester, epoxide, aldehyde, maleimide, imidoester, acrylate, and the like. NHS esters are useful groups for crosslinking with nucleophilic polymers, such as primary amine- or thiol-terminated polyethylene glycols, or other nucleophilic group-containing agents (e.g., nucleophilic group-containing crosslinking agents). NHS-amine crosslinking reactions can be carried out in aqueous solution in the presence of buffers (e.g., phosphate buffer (pH 5.0-7.5), triethanolamine buffer (pH 7.5-9.0), borate buffer (pH 9.0-12), or sodium bicarbonate buffer (pH 9.0-10.0)).

[0109] In certain embodiments, each precursor may contain only nucleophilic or only electrophilic functional groups, so long as both nucleophilic and electrophilic precursors are used in the crosslinking reaction. Thus, for example, if the crosslinker has only nucleophilic functional groups (e.g., amines), the precursor polymer may have electrophilic functional groups (e.g., N-hydroxysuccinimide). On the other hand, if the crosslinker has electrophilic functional groups such as sulfosuccinimide, the functional polymer may have nucleophilic functional groups such as amines or thiols. Thus, functional polymers (e.g., proteins, poly(allylamine), or amine-terminated di- or multifunctional poly(ethylene glycol)s) can also be used to prepare the polymer networks of the present invention.

[0110] In one embodiment of the invention, the precursors of the polymer network forming the hydrogel in which the antibiotic is dispersed to form the insert according to the invention each have from about 2 to about 16 nucleophilic functional groups (referred to as functionality), and in another embodiment, the precursors each have from about 2 to about 16 electrophilic functional groups (referred to as functionality). Reactive precursors having reactive (nucleophilic or electrophilic) groups that are multiples of 4, thereby, for example, 4, 8, and 16 reactive groups, are particularly suitable for the present invention. However, any number of functional groups (e.g., when using precursors, including any of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 groups) can be used in accordance with the present invention while ensuring that the functionality is sufficient to form a fully crosslinked network.

[0111] PEG hydrogel In certain embodiments of the invention, the polymer network forming the hydrogel comprises polyethylene glycol ("PEG") units, which are known in the art to form hydrogels when crosslinked, and these PEG hydrogels are suitable for pharmaceutical applications, for example as matrices for drugs intended to be administered to any part of the human or animal body.

[0112] The polymer network of the hydrogel insert of the invention may include one or more multi-arm PEG units having 2-10 arms, or 4-8 arms, or 4, 5, 6, 7, or 8 arms. In certain embodiments, the PEG units used in the hydrogels of the invention have 4 arms. In certain embodiments, the PEG units used in the hydrogels of the invention have 8 arms. In certain embodiments, PEG units having 4 arms and PEG units having 8 arms are used in the hydrogels of the invention. In certain embodiments, one or more 4-arm PEGs are utilized. Any combination of multi-arm PEGs may be used. In certain embodiments, only 4-arm PEG units are used (which may be the same or different).

[0113] The number of arms of the PEG(s) used helps control the flexibility or softness of the resulting hydrogel. For example, hydrogels formed by crosslinking 4-arm PEG are typically softer and more flexible than those formed from 8-arm PEG of the same molecular weight. A softer hydrogel (e.g., 4-arm PEG) can be used, optionally in combination with another multi-arm PEG (e.g., the 8-arm PEG disclosed above, or another (different 4-arm PEG)), especially if it is desired to stretch the hydrogel before (or even after) drying, as described below in the section on making inserts herein.

[0114] In certain embodiments of the invention, the average molecular weight (Mn) of the polyethylene glycol units used as precursors is in the range of about 2,000 to about 100,000 daltons, or in the range of about 10,000 to about 60,000 daltons, or in the range of about 15,000 to about 50,000 daltons. In certain embodiments, the average molecular weight of the polyethylene glycol units is in the range of about 10,000 to about 40,000 daltons, or in the range of about 15,000 to about 30,000 daltons, or in the range of about 15,000 to about 25,000 daltons. In certain embodiments, the average molecular weight (Mn) of the polyethylene glycol units used to prepare the hydrogels according to the invention is about 20,000 daltons. Polyethylene glycol precursors of different molecular weights can be combined with each other. As used herein, when referring to a PEG material having a particular average molecular weight (as defined herein) (e.g., about 20,000 daltons), a variation of ±10% is intended to be included, i.e., a reference to a material having an average molecular weight of about 20,000 daltons also refers to such materials having average molecular weights of about 18,000 to about 22,000 daltons. As used herein, the abbreviation "k" in the context of molecular weight refers to 1,000 daltons, i.e., "20k" means 20,000 daltons.

[0115] Additionally, when referring to a PEG precursor having a particular average molecular weight (e.g., a 15k PEG or 20k PEG precursor), the indicated average molecular weight (i.e., Mn of 15,000 or 20,000, respectively) refers to the PEG portion of the precursor before end groups are added (as used herein, "20k" means 20,000 daltons and "15k" means 15,000 daltons - the same abbreviations are used herein for PEG precursors of other average molecular weights). In certain embodiments, the Mn of the precursor PEG portion is determined by MALDI. The degree of substitution with the end groups disclosed herein can be determined after end group functionalization by: 1 It can be determined by H-NMR.

[0116] In a 4-arm ("4a") PEG, in certain embodiments, the average arm length (or molecular weight) of each arm may be the total molecular weight of the PEG divided by 4. A particularly suitable precursor for use in the present invention, the 4a20k PEG precursor, has four arms with an average molecular weight of about 5,000 Daltons each and a total molecular weight of 20,000 Daltons. Thus, the 8a20k PEG precursor, which may be used in combination with or instead of the 4a20k PEG precursor in the present invention, has eight arms ("8a") with an average molecular weight of 2,500 Daltons each and a total molecular weight of 20,000 Daltons. Longer arms may provide more flexibility compared to shorter arms. PEGs with longer arms may swell more compared to PEGs with shorter arms. PEGs with fewer arms may swell more and be more flexible than PEGs with more arms. In certain embodiments, the present invention uses only one or more 4-arm PEG precursor(s). In other specific embodiments, the present invention uses a combination of one or more 4-arm PEG precursor(s) and one or more 8-arm PEG precursor(s). Additionally, longer PEG arms may result in a higher melting point when dry, which may improve dimensional stability during storage.

[0117] In certain embodiments, the electrophilic end groups used with the PEG precursors to prepare the hydrogels of the present invention are N-hydroxysuccinimidyl (NHS) esters, including, but not limited to, NHS dicarboxylate esters such as succinimidyl malonate, succinimidyl malate, and succinimidyl fumarate groups, "SAZ" referring to succinimidyl azelate end groups, "SAP" referring to succinimidyl adipate end groups, "SG" referring to succinimidyl glutarate end groups, and "SS" referring to succinimidyl succinate end groups. Examples of active esters in addition to NHS esters useful in the present invention include, but are not limited to, thioesters, benzotriazolyl esters, and acrylate esters.

[0118] In certain embodiments, the nucleophilic end groups used with the electrophilic group-containing PEG precursors to prepare the hydrogels of the present invention are amine (designated "NH") end groups. Thiol (-SH) end groups or other nucleophilic end groups are also possible.

[0119] In certain embodiments of the invention, 4-arm PEG having an average molecular weight of about 20,000 Daltons and electrophilic end groups as disclosed above (e.g., SAZ, SAP, SG, and SS end groups, particularly SG end groups) is crosslinked to form a polymer network and thereby a hydrogel according to the invention. Suitable PEG precursors are available from a number of suppliers, such as Jenkem Technology.

[0120] For example, reaction of a nucleophilic group-containing crosslinker and an electrophilic group-containing PEG unit (e.g., reaction of an amine group-containing crosslinker with an activated ester group-containing PEG unit) results in multiple PEG units crosslinked with hydrolyzable linkers having the following formula: [ka] (wherein m is an integer from 0 to 10, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10). For SAZ end groups, m is 6, for SAP end groups, m is 3, for SG end groups, m is 2, and for SS end groups, m is 1. In certain embodiments, m is 2. All crosslinks in the polymer network can be the same or different.

[0121] In certain embodiments, the polymer precursors used to form hydrogels according to the present invention are selected from 4a20kPEG-SAZ, 4a20kPEG-SAP, 4a20kPEG-SG, 4a20kPEG-SS, 8a20kPEG-SAZ, 8a20kPEG-SAP, 8a20kPEG-SG, 8a20kPEG-SS, or mixtures thereof, which contain one or more PEG or lysine-based amine groups selected from 4a20kPEG-NH2, 8a20kPEG-NH2, and trilysine, or a trilysine salt or derivative (e.g., trilysine acetate).

[0122] In certain embodiments, SG end groups are utilized in the present invention, which may result in a shorter time for the hydrogel to biodegrade in an aqueous environment, such as in tears, compared to other end groups, such as SAZ end groups. SAZ end groups provide a higher number of carbon atoms in the linker, and therefore are more hydrophobic, which may make them less susceptible to ester hydrolysis than SG end groups.

[0123] In a particular embodiment, a 4-arm 20,000 dalton PEG precursor having SG end groups (as defined above) is crosslinked with a crosslinker having one or more reactive amine end groups. This PEG precursor is abbreviated herein as 4a20kPEG-SG. The schematic chemical structure of 4a20kPEG-SG is reproduced below: [ka] In this formula, n is determined by the molecular weight of each PEG arm.

[0124] In certain embodiments, the crosslinking agent used (also referred to herein as "crosslinker") is a low molecular weight component containing a nucleophilic end group (e.g., an amine or thiol end group). In certain embodiments, the nucleophilic group-containing crosslinking agent is a low molecular weight amine having a molecular weight of less than 1,000 Da. In certain embodiments, the nucleophilic group-containing crosslinking agent contains two, three, or more primary aliphatic amine groups. Crosslinking agents suitable for use in the present invention include (but are not limited to) spermine, spermidine, lysine, dilysine, trilysine, tetralysine, polylysine, ethylenediamine, polyethyleneimine, 1,3-diaminopropane, 1,3-diaminopropane, diethylenetriamine, trimethylhexamethylenediamine, 1,1,1-tris(aminoethyl)ethane, pharma- ceutically acceptable salts, hydrates or other solvates thereof, and derivatives thereof, such as conjugates (as long as there are sufficient nucleophilic groups for crosslinking), as well as mixtures thereof. A specific crosslinker used in the present invention is a lysine-based crosslinker, such as trilysine or a trilysine salt or derivative. A specific nucleophilic crosslinker used in the present invention is trilysine acetate. Other low molecular weight multi-arm amines may also be used. The chemical structure of trilysine is reproduced below. [ka]

[0125] In a very particular embodiment of the present invention, the 4a20kPEG-SG precursor is reacted with trilysine acetate to form the polymer network.

[0126] In certain embodiments, the nucleophilic group-containing crosslinker is bound to or conjugated with a visualization agent. Fluorophores, such as fluorescein, rhodamine, coumarin, and cyanine, can be used as visualization agents disclosed herein. In certain embodiments of the present invention, fluorescein is used as the visualization agent. The visualization agent can be conjugated to the crosslinker, for example, via some of the nucleophilic groups of the crosslinker. Since a sufficient amount of nucleophilic groups is required for crosslinking, "conjugated" or "conjugation" generally includes partial conjugation, meaning that only some of the nucleophilic groups can be used for conjugation with the visualization agent, for example, about 1% to about 20%, or about 5% to about 10%, or about 8% of the nucleophilic groups of the crosslinker can be conjugated to the visualization agent. In certain embodiments, the crosslinker is trilysine acetate and is conjugated to fluorescein.

[0127] In other embodiments, the visualization agent may be conjugated to the polymer precursor, for example, via certain reactive (e.g., electrophilic) groups of the polymer precursor. In certain embodiments, the crosslinker or the polymer precursor itself may contain, for example, a fluorophoric group or other visualization capable group.

[0128] The present invention contemplates that the visualization agent will be conjugated to the polymer precursor(s) or crosslinker disclosed below, which will retain the visualization agent within the hydrogel while the active agent is released into the tear fluid, thereby allowing for a convenient and non-invasive method of confirming the presence of the insert within the lacrimal canaliculus.

[0129] In certain embodiments, the molar ratio of nucleophilic and electrophilic end groups reacting with each other is about 1:1, i.e., one amine group is provided for every electrophilic group (e.g., SG group). In the case of 4a20kPEG-SG and trilysine (acetate), this results in a molar ratio of the two components of about 1:1, since trilysine has four primary amine groups that can react with electrophilic SG ester groups. However, an excess of either the electrophilic (e.g., NHS, e.g., SG) end group precursor or the nucleophilic (e.g., amine) end group precursor can be used. In particular, an excess of nucleophile (e.g., amine end group containing precursor or crosslinker) can be used. In certain embodiments, the molar ratio of electrophilic group containing precursor to nucleophilic group containing crosslinker, e.g., 4a20kPEG-SG to trilysine acetate, is about 1:2 to about 2:1.

[0130] Finally, in an alternative embodiment, the amine coupling agent can also be another PEG precursor having the same or a different arm number and the same or a different arm length (average molecular weight) as 4a20kPEG-SG, but having a terminal amine group (i.e., 4a20kPEG-NH2).

[0131] Additional Ingredients The insert of the present invention may contain other additional components in addition to the polymeric units forming the polymer network and the active ingredient disclosed above. Such additional components are, for example, salts derived from the buffer used during the preparation of the hydrogel, such as phosphates, borates, bicarbonates, or other buffering agents, such as triethanolamine. In a particular embodiment of the present invention, sodium phosphate buffers (particularly monobasic and dibasic sodium phosphate) are used.

[0132] In certain embodiments, the inserts of the present invention are free of antimicrobial preservatives or at least free of significant amounts of antimicrobial preservatives, including but not limited to benzalkonium chloride (BAK), chlorobutanol, sodium perborate, and stabilized oxychloro complexes (SOC).

[0133] In a more specific embodiment, the inserts of the present invention contain no animal or human derived components, only synthetic components.

[0134] In certain embodiments, the insert of the present invention comprises a visualization agent. The visualization agent used according to the present invention is any agent that can be conjugated to a component of the hydrogel or trapped within the hydrogel and is visible or can become visible, for example, when exposed to a certain wavelength of light, or is a contrast agent. Visualization agents suitable for use in the present invention include, but are not limited to, for example, fluorescein, rhodamine, coumarin, cyanine, europium chelate complex, boron dipyrromethene, benzofurazan, dansyl, bimane, acridine, triazapentalene, pyrene, and derivatives thereof. Such visualization agents are commercially available, for example, from TCI. In certain embodiments, the visualization agent is a fluorophore, such as fluorescein, or includes a fluorescein moiety. Visualization of the fluorescein-containing insert is possible with illumination using blue light and yellow filters. The fluorescein in the intracanalicular insert emits light when excited with blue light, making it possible to confirm the presence of the insert. In certain embodiments, the visualization agent is conjugated with one of the components that form the hydrogel. For example, the visualization agent, such as fluorescein, is conjugated with a crosslinking agent, such as trilysine or a trilysine salt or derivative (e.g., trilysine acetate), or with a PEG component. For example, NHS-fluorescein can be conjugated with trilysine acetate before crosslinking reaction with PEG precursor(s). The conjugation of the visualization agent prevents the visualization agent from eluting or being released from the insert. Since a sufficient amount of nucleophilic groups (at least one equivalent or more) is required for crosslinking, partial conjugation of the visualization agent with, for example, the crosslinking agent disclosed above can be performed.

[0135] The insert of the present invention may contain a surfactant in certain embodiments. The surfactant may be a non-ionic surfactant. The non-ionic surfactant may include a poly(ethylene glycol) chain. Exemplary non-ionic surfactants are poly(ethylene glycol) sorbitan monolaurates commercially available as Tween® (specifically Tween® 20, which is PEG-20-sorbitan monolaurate, or Tween® 80, which is PEG-80-sorbitan monolaurate), poly(ethylene glycol) esters of castor oil commercially available as Cremophor (specifically Cremophor 40, which is PEG-40-castor oil), and ethoxylated 4-tert-octylphenol / formaldehyde condensation polymers commercially available as Tyloxapol, and others such as Triton. The surfactant may aid in the dispersion of the active ingredient, prevent particle agglomeration, and may also reduce the likelihood of the hydrogel strands adhering to the tube during drying.

[0136] formulation In certain embodiments, an insert according to the invention comprises an antibiotic, such as besifloxacin, a polymer network (in the form of a hydrogel) made from one or more polymer precursors disclosed herein, and any additional components (e.g., visualization agents), salts (e.g., phosphates used as buffers), etc., that remain in the insert from the production process. In certain preferred embodiments, the antibiotic is besifloxacin. In certain embodiments, the insert is preservative-free.

[0137] In some embodiments, the insert according to the invention in a dry state contains about 25% to about 75% by weight of an antibiotic (e.g., besifloxacin) and about 75% to about 25% by weight of a polymer unit (e.g., those disclosed above). In further embodiments, the insert according to the invention in a dry state contains about 30% to about 60% by weight of an antibiotic (e.g., besifloxacin) and about 30% to about 60% by weight of a polymer unit (e.g., those disclosed above).

[0138] In certain embodiments, an insert according to the present invention in a dry state contains from about 40% to about 65% by weight of an antibiotic (e.g., besifloxacin) and from about 30% to about 50% by weight of a polymer unit (e.g., the polyethylene glycol units disclosed above).

[0139] In certain embodiments, the insert according to the invention may contain, in the dry state, about 0.1% to about 1% by weight of a visualization agent, such as fluorescein or a molecule containing a fluorescein moiety. Also, in certain embodiments, the insert according to the invention may contain, in the dry state, about 0.5% to about 5% by weight of one or more buffer salt(s) (separately or together). In certain embodiments, the insert in the dry state may contain, for example, about 0.01% to about 2% by weight, or about 0.05% to about 0.5% by weight of a surfactant.

[0140] In certain embodiments, the remainder of the dry insert (i.e., the remainder of the formulation when the antibiotic, such as besifloxacin, and the polymer hydrogel (e.g., trilysine-crosslinked PEG hydrogel), and optionally the visualization agent (e.g., fluorescein) have already been taken into account) may be salts remaining from the buffer used during the manufacture of the insert disclosed herein or other components used during the manufacture of the insert (e.g., surfactants, if used). In certain embodiments, such salts are phosphates, borates, or (bi)carbonates. In one embodiment, the buffer salt is sodium phosphate (monobasic and / or dibasic).

[0141] The amounts of antibiotic and polymer(s) may vary, and amounts of antibiotic and polymer hydrogel other than those disclosed herein may also be used to prepare an insert according to the present invention.

[0142] In certain embodiments, about 20% to about 50% (w / v) solids (where "solids" means the combined weight of the polymer precursor(s), optional visualization agent, salts, and drug in solution) are utilized to form an insert hydrogel according to the present invention.

[0143] In certain embodiments, the water content of a hydrogel in a dry (dehydrated / dried) state may be low, e.g., at most about 1% water by weight (e.g., determined as disclosed herein). In certain embodiments, the water content may also be lower, perhaps about 0.25% or less by weight, or about 0.1% or less by weight.

[0144] Insert dimensions and dimensional change upon moisture absorption The dry insert may have different shapes depending on the method of manufacture (e.g., the inner or outer diameter of the mold or tube into which the mixture containing the antibiotic-containing hydrogel precursor is cast prior to complete gelation). The insert according to the invention is also referred to as a "fiber" (a term used interchangeably herein with the term "rod"), and generally, the length of the fiber exceeds its diameter. The insert (or fiber) may have different shapes with the specific dimensions disclosed herein.

[0145] In one embodiment, the insert is cylindrical or essentially cylindrical in shape. Whenever "cylindrical" is mentioned herein in the specification or claims with respect to the outer shape of the insert, this always includes "essentially cylindrical". In this case, the insert has a circular or essentially circular cross section. In other embodiments of the invention, the insert is non-cylindrical. The insert according to the invention is optionally elongated in the dry state, the length of the insert being greater than the width of the insert, the width being the largest cross-sectional dimension substantially perpendicular to the length. For cylindrical or essentially cylindrical inserts, the width is also referred to as the diameter.

[0146] Various shapes of the outer insert's profile or its cross section may also be used in the present invention. For example, instead of a circular diameter fiber (i.e., in the case of a cylindrical insert), an elliptical (or oval) diameter fiber may be used. Elliptical or other cross-sectional shapes, such as rectangular, oblong, triangular, star, cross, etc., may generally be used. As disclosed herein, the exact cross-sectional shape is not critical since tissue will form around the insert, so long as the insert's diameter expands to the water-absorbed diameter when it absorbs water within the canaliculus. In certain embodiments, the ratio of the insert's length in the water-absorbed state to the insert's diameter is at least about 1, or at least about 1.1, or at least about 1.2, which helps to hold the insert in place within the canaliculus, prevents the insert from twisting and rotating within the canaliculus, and also helps to maintain intimate contact with the surrounding tissue. In certain embodiments, this ratio may be less than about 2, or less than about 1.75.

[0147] The polymer network (e.g., PEG network) of the hydrogel insert according to certain embodiments of the invention can be semi-crystalline in the dry state at or below room temperature and amorphous in the wet state. Even in the stretched form, the dry insert can be dimensionally stable at or below room temperature, which can be advantageous for administering the insert into the lacrimal canalicular canalicular canalicular canalveolar canalicular ...

[0148] Upon hydration of the insert in the canaliculus by the tear fluid (which can be simulated in vitro, for example, by immersing the insert in PBS at pH 7.4 at 37° C. after 24 hours, which is considered to be in equilibrium), the dimensions of the insert according to the present invention may change. In general, the diameter of the insert may increase, while its length may decrease, or in certain embodiments, may remain the same or substantially the same. The advantage of this dimensional change is that the insert in the dry state is thin enough to be administered and placed in the canaliculus through the punctum (whose diameter is smaller than the canaliculus) upon hydration, but thereby fits closely to the canaliculus through the expansion of its diameter, thereby acting as a canaliculus plug. Thus, the insert provides tear duct occlusion, thereby preserving tears, in addition to releasing the active ingredient in a controlled manner to the tear fluid over a period of time, as disclosed herein.

[0149] In certain embodiments, as also disclosed herein, this dimensional change is made possible, at least in part, by a "shape memory" effect introduced into the insert by longitudinally stretching the hydrogel strands during manufacture. In certain embodiments, this stretching can be performed in a wet state, i.e., before drying. However, in other certain embodiments, stretching of the hydrogel strands (after casting and curing) can be performed in a dry state (i.e., after drying the hydrogel strands). It is noted that if no stretching is performed, the insert may simply expand due to the absorption of water, but the dimensional changes of increasing diameter and decreasing length disclosed herein may not be achieved, or may not be achieved to a large extent. This may result in the insert not being optimally fixed in the canaliculus, and may result in the insert being cleared through the nasolacrimal duct or lacrimal punctum (potentially before the entire amount of active ingredient is released). If this is undesirable, the hydrogel strands may be stretched, for example, dry or wet, to cause an expansion of diameter upon rehydration.

[0150] In the hydrogels of the present invention, some degree of molecular orientation can be imparted by stretching the material and then fixing it to fix the molecular orientation. Molecular orientation provides one mechanism for anisotropic swelling when the insert is contacted with a moisture-absorbing medium, such as tears. Upon moisture absorption, the inserts of certain embodiments of the present invention expand only in the radial dimension, but reduce or maintain or substantially maintain their length. The term "anisotropic expansion" refers to preferential expansion in one direction rather than another, such as a cylinder that expands primarily in the diametric direction but does not expand (or shrink) significantly in the longitudinal direction.

[0151] The extent of the dimensional change upon water absorption may depend, inter alia, on the stretching factor. As a mere example to illustrate the effect of stretching, stretching (e.g., by wet stretching) with a stretching factor of, for example, about 1.3 may not have a significant effect or may not significantly change the length and / or diameter upon water absorption. In contrast, stretching (e.g., by wet stretching) with a stretching factor of, for example, about 1.8 may result in a shorter length and / or an increased diameter upon water absorption. Stretching (e.g., by dry stretching) with a stretching factor of, for example, about 3 or 4 may result in a much shorter length and a much larger diameter upon water absorption. Those skilled in the art will understand that factors other than stretching may also affect the swelling behavior.

[0152] Among other factors that influence the ability of the hydrogel to stretch and cause dimensional changes of the insert upon water absorption is the composition of the polymer network. When PEG precursors are used, those with fewer arms (e.g., 4-arm PEG precursors) tend to make the hydrogel more flexible than those with a larger number of arms (e.g., 8-arm PEG precursors). If the hydrogel contains more components with less flexibility (e.g., a higher amount of PEG precursors with a higher number of arms (e.g., 8-arm PEG units)), the hydrogel may be stiffer and less easily stretched without breaking. On the other hand, hydrogels containing more flexible components (e.g., PEG precursors with fewer arms, e.g., 4-arm PEG units) may be more easily stretched and flexible, but also swell more upon water absorption. Thus, the behavior and properties of the insert when administered and rehydrated can be tailored by altering the structural features and by modifying the treatment of the insert after it is initially formed.

[0153] The dimensions of the dry insert may depend, among other things, on the amount of antibiotic incorporated and the ratio of antibiotic to polymer units, and may further be controlled by the diameter and shape of the mold or tube in which the hydrogel is gelled. The diameter of the dry insert may be further controlled by stretching (wet or dry) the hydrogel strands formed as disclosed herein. The dry hydrogel strands (after stretching) are cut into pieces of desired length to form the insert; thus, the length may be selected as needed.

[0154] In the following, embodiments of inserts having specific dimensions are disclosed. The dimensional ranges or values ​​disclosed in certain embodiments herein relate to the length and diameter of cylindrical or essentially cylindrical inserts. However, all values ​​and ranges for cylindrical inserts may be used for non-cylindrical inserts as well. If measurements of the length or diameter of one insert are performed multiple times or multiple data points are collected during a measurement, the average (i.e., mean) value is reported as defined herein. The length and diameter of inserts according to the present invention may be measured, for example, by a microscope or a (optionally automated) camera system. Other suitable methods of measuring the dimensions of inserts may also be used.

[0155] In one embodiment, the present invention relates to a sustained release biodegradable intracanalicular insert comprising a hydrogel and an antibiotic, the length of the insert in a dry state being about 3.00 mm or less, hi a particular embodiment, the antibiotic is besifloxacin.

[0156] In certain embodiments of the invention, the dry insert is about 2.8 mm or more in length, or greater than about 2.6 mm, or about 2.5 mm in length. In certain embodiments of the invention, the dry insert is greater than about 1 mm in length, or greater than about 1.5 mm, or greater than about 2 mm in length. In certain embodiments, the dry insert is less than about 2.5 mm in length, and greater than about 1.5 mm in length.

[0157] In alternative embodiments, the length of the insert may be from about 0.5 mm to about 3 mm (e.g., from about 0.5 mm to about 2.5 mm, from about 1 mm to about 2.5 mm, from about 1.25 mm to about 2.5 mm, from about 1.5 mm to about 2.25 mm, about 0.5 mm, about 0.75 mm, about 1 mm, about 1.25 mm, about 1.5 mm, about 1.75 mm, about 2.0 mm, about 2.25 mm, about 2.5 mm, about 2.75 mm, or about 3 mm).

[0158] In certain embodiments of the invention, the diameter of the insert in its dry state is less than about 1 mm, or less than about 0.8 mm, or less than about 0.75 mm, or less than about 0.6 mm, or between about 0.40 mm and about 0.6 mm, or about 0.5 mm, or about 0.6 mm.

[0159] In certain embodiments, the insert according to the invention is cylindrical or essentially cylindrical, and upon hydration (in the canaliculus in vivo or in vitro after 24 hours in phosphate buffered saline at pH 7.2 at 37° C.), the diameter of the insert increases and the length of the insert decreases. In particular, the diameter of the insert may increase by a factor ranging from about 1.5 to about 4 times, or from about 2 to about 3.5 times, or from about 3 times. In other words, the ratio of the diameter of the insert in the hydrated state to the diameter of the insert in the dry state may range from about 1.5 to about 4, or from about 2 to about 3.5, or about 3.

[0160] In certain embodiments, the length of the insert according to the present invention is reduced after moisture absorption to about 0.99 times or 0.95 times the length in the dry state, or to about 0.75 times the length in the dry state, or to about two-thirds of the length in the dry state. In other words, the ratio of the length of the insert in the moisture-absorbing state to the length of the insert in the dry state can be about 0.99 or less, or about 0.95 or less, or about 0.9 or less, or about two-thirds or less, and can be at least about 0.25 or at least about 0.4.

[0161] Thus, in certain embodiments, the insert according to the present invention has a diameter in the range of about 1 to about 2.5 mm in a hydrated state, and has a length shorter than the length of the insert in a dry state. In certain embodiments, in a hydrated state, for example when the insert is placed in the canaliculus, the length to diameter ratio of the insert is suitably greater than 1, i.e., the length of the insert is longer than the diameter. This helps to hold the insert in place in the canaliculus without any twisting or rotation. This helps to occlude the canaliculus / punctum, retain tears in the eye, and ensure contact of the surface of the insert with the tears to release the antibiotic, such as besifloxacin.

[0162] In certain embodiments, the inserts according to the invention in their hydrated state have diameters ranging from about 1.4 mm to about 2.2 mm, or from about 1.6 mm to about 2.0 mm, or about 1.8 mm.

[0163] In certain embodiments, the dimensional change may be achieved by wet stretching the hydrogel strands with a stretch factor ranging from about 1.5 to about 3, or from about 2.2 to about 2.8, or from about 2.5 to about 2.6, while in other embodiments, such dimensional change may be achieved by dry stretching.

[0164] In certain embodiments, such stretching creates a shape memory, meaning that the insert will shrink in length and expand in diameter upon water absorption and contact with tear fluid when administered to the canaliculus until it approaches (more or less) its equilibrium dimensions (determined by, among other things, the original molded dimensions and compositional variables). A narrow dry dimension facilitates administration of the insert to the canaliculus through the punctum, whereas the expansion in diameter and shortening in length after administration results in a shorter and wider insert that closely fits and occludes the canaliculus while releasing the active agent primarily at its proximal surface (the surface of the insert in contact with tear fluid and directed towards the punctal opening).

[0165] In certain embodiments, the total weight of an insert of the present invention is in the range of about 50 to about 1500 μg, such as in the range of about 100 to about 1000 μg, or in the range of about 200 to about 800 μg.

[0166] Release of active substances and biodegradation of inserts In one embodiment, the invention relates to a sustained release biodegradable intraocular (e.g., intracanalicular) insert comprising a hydrogel and an antibiotic, wherein the insert releases a therapeutically effective amount of the antibiotic for up to about 14 days, up to about 21 days, up to about 30 days, or up to about 42 days after administration (i.e., after insertion into the canaliculus). In a particular embodiment, the antibiotic is besifloxacin.

[0167] In certain embodiments, the active agent gradually dissolves and diffuses out of the hydrogel into the tear fluid, primarily in one direction, beginning at the interface of the insert and the tear fluid at the proximal surface of the insert, with the "drug front" generally progressing in the opposite direction, i.e., away from the proximal surface, until eventually the entire insert is depleted of active agent.

[0168] In certain embodiments, after administration, the level of active agent released from the insert per day is sustained, constant, or remains essentially constant for a period of time (e.g., about 7 days, or about 11 days, or about 14 days) in the case of besifloxacin (due to release limitations based on the solubility of the active agent). The amount of active agent released per day may then decrease (also referred to as "tapering") for another period of time, e.g., about another 7 days (or more in certain embodiments) in the case of besifloxacin, until all or substantially all of the active agent has been released, and the "empty" hydrogel remains in the lacrimal canaliculus until it is completely degraded and / or cleared (excreted / flowed out) through the nasolacrimal duct.

[0169] In certain embodiments, when drug is released primarily from the proximal surface of the insert, this region of the hydrogel insert is devoid of drug particles and may therefore also be referred to as the "clearance zone." In certain embodiments, upon hydration, the "clearance zone" becomes a region of the insert that has a lower concentration of active drug than another region of the hydrated hydrogel. As the clearance zone increases, a concentration gradient is created within the insert that may cause the release rate of the drug to taper off.

[0170] In certain embodiments, as the drug diffuses out of the hydrogel (even after the entire amount of drug has diffused out of the hydrogel), the hydrogel may slowly degrade, for example, by ester hydrolysis in the aqueous environment of the tear fluid. As the degradation stage progresses, distortion and erosion of the hydrogel begins to occur. As this occurs, the hydrogel becomes softer and more liquid (and thus distorts its contour) until eventually the hydrogel dissolves and is completely resorbed. However, as the hydrogel becomes softer, thinner, and distorts, at some point it may no longer remain at the intended site within the canaliculus where it was administered, but may progress deeper into the canaliculus and eventually be cleared (excreted / flowed out) through the nasolacrimal duct.

[0171] In one embodiment, the persistence of the hydrogel in an aqueous environment, such as the human eye (including the lacrimal canaliculus), depends, among other things, on the structure of the linker that crosslinks the polymer units (e.g., PEG units) in the hydrogel. In certain embodiments, the hydrogel is biodegraded within a period of about 2 weeks, or about 1 month, or about 2 months, or about 3 months, or up to about 4 months after administration. However, during the degradation process in an aqueous environment (e.g., tears in the lacrimal canaliculus), the hydrogel gradually softens and deforms, and the insert may be cleared (flowed / excreted) through the nasolacrimal duct before it is completely biodegraded.

[0172] In embodiments of the invention, the hydrogel, and thereby the implant, remains within the lacrimal canaliculus for up to about 2 weeks, 1 month, or up to about 2 months, or up to about 3 months, or up to about 4 months after administration.

[0173] In certain embodiments of the invention, when the antibiotic is besifloxacin, the entire amount of besifloxacin may be released prior to complete degradation of the hydrogel, and the insert may persist in the canaliculus thereafter for a total of up to about 2 weeks, up to about 1 month, or up to about 2 months, or up to about 3 months, or up to about 4 months after administration. In other specific embodiments, the hydrogel may be completely biodegraded when the antibiotic, such as besifloxacin, has not yet been completely released from the insert. In other embodiments, the insert may be completely degraded after release of at least about 90%, or at least about 92%, or at least about 95%, or at least about 97% of the antibiotic.

[0174] In certain embodiments, in vitro release testing may be used to compare different inserts (e.g., those of different manufacturing batches, different compositions, different dosage strengths, etc.) with each other, for example, for quality control or other qualitative evaluation purposes. The in vitro release of antibiotics from the inserts of the present invention can be measured in various ways, for example, under non-settling artificial physiological conditions in PBS (phosphate buffered saline, pH 7.4) at 37° C. (daily replacement of an amount of PBS equivalent to the tear fluid of the human eye).

[0175] Manufacturing of inserts In certain embodiments, the present invention also relates to methods of making the sustained release biodegradable intracanalicular insert disclosed herein, comprising a hydrogel and an antibiotic, such as besifloxacin.

[0176] In certain embodiments, a method of manufacture according to the present invention includes forming a hydrogel including a polymer network (e.g., including PEG units) and antibiotic particles dispersed within the hydrogel, molding or casting the hydrogel, and drying the hydrogel. In one embodiment, an antibiotic such as besifloxacin may be used in micronized form to prepare an insert, as disclosed herein. In another embodiment, an antibiotic such as besifloxacin may be used in micronized form to prepare an insert.

[0177] Precursors suitable for forming hydrogels of certain embodiments of the invention are as disclosed above in the section relating to the insert itself. In certain embodiments, the hydrogels are made from polymer networks comprising cross-linked polyethylene glycol units as disclosed herein. The polyethylene glycol (PEG) units in certain embodiments are multi-armed, such as 4-armed, PEG units having an average molecular weight of about 2,000 to about 100,000 daltons, or about 10,000 to about 60,000 daltons, or about 15,000 to about 50,000 daltons, or about 20,000 daltons. Suitable PEG precursors having reactive groups, such as electrophilic groups, as disclosed herein, are cross-linked to form polymer networks. Cross-linking can be performed with a cross-linking agent, either a small molecule compound or another polymeric compound (including another PEG precursor) having a reactive group, such as a nucleophilic group, as also disclosed herein. In certain embodiments, a PEG precursor having an electrophilic end group is reacted with a cross-linking agent (a small molecule compound or another PEG precursor) having a nucleophilic end group to form a polymer network.

[0178] In a specific embodiment, a method for making an insert of the invention comprises mixing and reacting an electrophilic group-containing multi-arm polyethylene glycol (e.g., 4a20kPEG-SG) with a nucleophilic group-containing crosslinker (e.g., trilysine acetate) in a buffer solution in the presence of besifloxacin particles, and allowing the mixture to gel. In certain embodiments, the molar ratio of electrophilic groups in the PEG precursor to nucleophilic groups in the crosslinker is about 1:1, but can range from about 2:1 to about 1:2.

[0179] In certain embodiments, the visualization agent disclosed herein is included in the mixture that forms the hydrogel so that the insert can be visualized when administered into the lacrimal canaliculus.For example, the visualization agent can be a fluorophore such as fluorescein, or a molecule that contains a fluorescein moiety, or another visualization agent as disclosed above.In certain embodiments, the visualization agent can be tightly conjugated to one or more components of the polymer network so that the visualization agent remains in the insert at all times until the insert is biodegraded.

[0180] The visualization agent can be conjugated to either a polymer such as PEG, a precursor, or a (polymeric or low molecular weight) crosslinker. In certain embodiments, the visualization agent is fluorescein, which is conjugated to a trilysine acetate crosslinker before reacting the crosslinker with a PEG precursor. For example, in the case of fluorescein, NHS-fluorescein (N-hydroxysuccinimidyl-fluorescein) can be reacted with trilysine acetate, and the completion of the formation of the trilysine-fluorescein conjugate can be monitored (e.g., by RP-HPLC with UV detection). This conjugate can then be used to further crosslink polymer precursor(s), such as 4a20kPEG-SG.

[0181] In certain embodiments, during the manufacture of the inserts of the invention, a mixture / suspension (optionally buffered) of antibiotic and PEG precursor(s) (e.g., besifloxacin and 4a20kPEG-SG) is prepared in water. The antibiotic / PEG precursor mixture is then mixed with a solution (optionally buffered solution) containing a crosslinker and a visualization agent conjugated thereto (e.g., lysine acetate / fluorescein conjugate). The resulting mixed mixture then contains antibiotic, polymer precursor(s), crosslinker, visualization agent, and (optionally) a buffer. In certain embodiments, once the mixture of electrophilic group-containing polymer precursor, nucleophilic group-containing crosslinker, antibiotic such as besifloxacin, optionally a visualization agent (optionally conjugated with a crosslinker), and optionally a buffer has been prepared (i.e., after these components are mixed), the resulting mixture is cast into a suitable mold or tube prior to complete gelation, for example, to provide a hydrogel strand and, ultimately, a hydrogel of the desired final configuration. The mixture is then allowed to gel. The resulting hydrogel is then dried.

[0182] If the final shape of the insert is cylindrical or essentially cylindrical, the hydrogel strands are prepared by casting the hydrogel precursor mixture containing the antibiotic particles into a tube of small diameter, such as a polyurethane (PU) tube. Depending on the desired final cross-sectional shape of the hydrogel strand and thus the final insert, its initial diameter (which may be further reduced by stretching), and the ability of the reaction mixture to fill the tube uniformly and be removed from the tube after drying, different shapes and diameters of tubes can be used. Thus, the inside of the tube may have a circular shape or a non-circular shape, for example an elliptical (or other) shape.

[0183] In certain embodiments, after the hydrogel strands have been formed and left in the tube to complete the curing and gelling process, the hydrogel strands may be stretched longitudinally in a wet or dry state, as disclosed herein. Stretching may result in a change in the dimensions of the insert upon water absorption, for example, after placement of the insert in the canaliculus. In certain embodiments, the hydrogel strands are stretched with a stretch factor in the range of about 1 to about 3, or about 1.5 to about 3, or about 2.2 to about 2.8, or about 2.5 to about 2.6, before (complete) drying. In certain embodiments, stretching may be performed while the hydrogel strands are still in the tube. Alternatively, the hydrogel strands may be removed from the tube before being stretched. In certain embodiments of the present invention, when dry stretching is performed, the hydrogel strands are first dried and then stretched (while still in the tube or after removal from the tube). In certain embodiments of the invention, when wet stretching is performed, the hydrogel is stretched in a wet state (i.e., before it is completely dry) and then dried under tension, optionally with the application of heat during stretching.

[0184] After stretching and drying the hydrogel strands may be removed from the tube and cut into segments of desired length as disclosed herein to produce the final insert (if cut within the tube, the cut segments are removed from the tube after cutting). Particularly desirable lengths for purposes of the present invention are, for example, lengths of about 3.0 mm or less, or about 2.75 mm or less, e.g., lengths ranging from about 2.0 mm to about 2.6 mm, or about 2.5 mm.

[0185] After cutting, the insert may then be packaged in a moisture-resistant package, such as a sealed foil pouch. The insert may be secured to a mount or support to hold it in place, to avoid damage to the insert, and also to facilitate gripping / holding the insert for removal from the package and administration to the patient. For example, the insert of the present invention may be secured to an opening in a foam carrier, with a portion of the insert protruding for easy removal and gripping (as shown in FIG. 1). The insert may be removed from the foam carrier with tweezers and then immediately inserted into the patient's lacrimal canaliculus.

[0186] Particular embodiments of the manufacturing process according to the invention are disclosed in detail in the examples.

[0187] In certain embodiments, the insert is manufactured by melt extrusion or injection molding.

[0188] The method may include feeding the polymer composition and the active agent into an extruder; mixing the components in the extruder; extruding the strands; and cutting the strands into unit dose inserts or implants.

[0189] In certain embodiments, the polymer composition and the active agent are fed separately into the extruder. In other embodiments, the polymer composition and the active agent are fed simultaneously into the extruder. In certain embodiments, the polymer composition is premixed (e.g., melt blended) before being introduced into the extruder. The mixing can be by methods such as using an orbital mixer, an acoustic mixer, or a V-shell blender. In certain embodiments, the polymer composition and the active agent are melt mixed, milled, and then fed into the extruder.

[0190] In certain embodiments, the method further includes cooling the extruded strands, for example, prior to cutting the strands.

[0191] In certain embodiments, the method further includes stretching the extruded strands, for example, prior to cutting the strands.

[0192] In certain embodiments, stretching is performed under wet or humid conditions, heated conditions, or a combination thereof. In other embodiments, stretching is performed under dry conditions, heated conditions, or a combination thereof. In certain embodiments, strands that are stretched after crosslinking in a humid environment (e.g., a humidity chamber) may have shape memory or partial shape memory when dried and placed in an aqueous environment. In certain embodiments, extruded strands that are stretched or otherwise made to have a smaller diameter immediately after extrusion while still warm and before crosslinking may not have shape memory.

[0193] In certain embodiments, the extruded composition is subjected to a curing step (e.g., exposure to humidity). When one reactant is a salt, such as an amine salt, the salt is insoluble in the dried polymer melt. In this case, curing is achieved by exposing the dried extruded composition to humidity, allowing the extruded composition to absorb water from the environment, thereby dissolving the salt and allowing it to react to crosslink the precursor and form the matrix. In certain embodiments, curing crosslinks the polymer composition.

[0194] In certain embodiments, the method further includes drying the extruded strands after stretching the strands.

[0195] In other embodiments, any of the steps of the methods disclosed herein may be performed simultaneously or sequentially.

[0196] In certain embodiments, the method further includes melting the polymer in the extruder at a temperature below the melting point of the active agent. The optimal temperature of the molten polymer is determined by experimentation depending on its extrusion properties. In certain embodiments, the unmolten active agent remains unchanged throughout this melt extrusion process. In certain embodiments, the extrusion is performed at a temperature above the melting point of the polymer and the active agent. This may result in a color change and / or a change in morphology of the active agent, for example, from amorphous to crystalline. The temperature may be, for example, less than about 180°C, less than about 150°C, less than about 130°C, less than about 120°C, less than about 100°C, less than about 90°C, less than about 80°C, less than about 70°C, less than about 60°C, less than about 50°C. In some embodiments, the temperature is about 50°C to about 80°C. In other embodiments, the temperature is about 50°C to about 200°C, about 60°C to about 180°C, or about 80°C to about 140°C. Exemplary temperatures are from about 40° C. to about 90° C. According to certain embodiments of the present invention, the temperature is kept as low as possible to protect the excipient powders and active ingredients and optimize stability. In certain embodiments, the active drug is nepafenac and the polymer is melted in the extruder at a temperature of from 57° C. to about 175° C., from about 65° C. to about 150° C., or from about 70° C. to about 90° C.

[0197] In certain embodiments, the extruded composition is dried in strand form or unit dose. In certain embodiments, drying is performed after stretching of the strands. Drying can be, for example, evaporative drying at ambient temperature or can include heat, vacuum, or a combination thereof.

[0198] In certain embodiments, the hydrogel strands are stretched with a stretch factor ranging from about 1.1 to about 10, 1.2 to about 6, or about 1.5 to about 4.

[0199] In certain embodiments, the strands are cut into pieces having an average length of about 20 mm, 17 mm, 15 mm, 12 mm, 10 mm, 8 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, or 0.5 mm or less, in certain embodiments, the size is about 0.5 mm to about 10 mm, about 1 mm to about 8 mm, or about 1.5 mm to about 5 mm.

[0200] In certain embodiments, the active agent is suspended in the polymer composition.

[0201] In certain embodiments, the active agent is homogeneously dispersed in the polymer composition.

[0202] In certain embodiments, the extrusion process is carried out without a solvent (e.g., water). In certain embodiments, a solvent is used in an amount of less than about 10% w / w, less than about 5% w / w, or less than about 1% w / w. The solvent can be, for example, water or oil. The oil can increase the release rate of lipophilic active agents. The oil can be a biocompatible vegetable oil, synthetic oil, or mineral oil, a liquid fatty acid or triglyceride composition, or it can be a hydrophobic biodegradable liquid polymer, or a combination thereof. In certain embodiments, the oil is selected from the group consisting of triethyl citrate, acetyl triethyl citrate (ATEC), acetyl tributyl citrate (ATBC), alpha-tocopherol (vitamin E), alpha-tocopherol acetate, vegetable oils such as sesame oil, olive oil, soybean oil, sunflower oil, coconut oil, canola oil, rapeseed oil, nut oils such as hazelnut, walnut, pecan, almond, cottonseed oil, corn oil, safflower oil, linseed oil, ethyl oleate, castor oil and its derivatives (Cremo), and the like. The lipids may include lipids that are liquid at or below 37° C., such as saturated or unsaturated fatty acids, monoglycerides, diglycerides, triglycerides (Myglyols®), phospholipids, glycerophospholipids, sphingolipids, sterols, prenol, polyketides, hydrophobic biodegradable liquid polymers (such as low molecular weight PLGA, PGA, or PLA), low melting point waxes, such as vegetable, animal, or synthetic waxes, lanolin, jojoba oil, or combinations thereof.

[0203] treatment In one aspect, the present invention relates to a method of treating an ocular infection in a patient in need of treatment, the method comprising administering to the patient a sustained release biodegradable intraocular (e.g., intracanalicular) insert disclosed herein.

[0204] The patient to be treated according to the present invention may be a human or animal subject in need of ocular infection treatment, including acute ocular infection treatment, hi certain embodiments, the patient may be a subject in need of acute treatment of intermittent recurring ocular infections.

[0205] In certain alternative embodiments, the treatment of the eye infection may be a long-term (or longer term) treatment of the eye infection.

[0206] In one embodiment, the present invention also relates to a sustained release biodegradable intraocular (eg, intracanalicular) insert as disclosed herein for use in treating an ocular infection in a patient in need of such treatment.

[0207] In one embodiment, the present invention also relates to the use of the sustained release biodegradable intraocular (e.g., intracanalicular) inserts disclosed herein in the manufacture of a medicament for treating an ocular infection in a patient in need of treatment.

[0208] Administration of the insert according to the invention is performed through the opening of the lacrimal punctum into the lower and / or upper canaliculus.

[0209] In certain embodiments, as disclosed herein, upon in vivo water absorption following administration to the canalicular canaliculus, a sustained release biodegradable intracanalicular insert administered to a patient can increase in diameter and decrease in length.

[0210] In certain embodiments, the insert is administered into the vertical portion of the lower canaliculus and / or the vertical portion of the upper canaliculus.

[0211] In certain embodiments, the sustained release biodegradable intracanalicular insert contains a visualization agent, such as fluorescein, to allow for rapid and non-invasive visualization of the insert when placed in the canaliculus. When the visualization agent is fluorescein, the insert can be visualized by illuminating with a blue light source and using a yellow filter.

[0212] In certain embodiments, an antibiotic such as besifloxacin is released from the insert and dissolves in the tear film, and is delivered from the insert to the ocular surface via the tear film. The antibiotic is released primarily from the proximal end of the insert at the interface of the hydrogel and the tear. The sustained release rate of the antibiotic is controlled by the solubility of the antibiotic in the hydrogel matrix and the tear. In certain embodiments, the antibiotic is besifloxacin.

[0213] In certain embodiments, even after the antibiotic such as besifloxacin is completely depleted from the insert, the insert remains in the canaliculus until the hydrogel biodegrades and / or is excreted (flows out / cleared) through the nasolacrimal duct. Because the hydrogel matrix of the insert is formulated to biodegrade (e.g., by ester hydrolysis) in the aqueous environment of the tears in the canaliculus, the insert softens and liquefies over time and is cleared from the nasolacrimal duct without the need for removal, thereby avoiding unpleasant removal. However, if the insert must be removed, for example, due to a potential allergic reaction or other situation that requires removal of the insert (e.g., an unpleasant foreign body sensation felt by the patient), or because the treatment should be stopped for another reason, the insert can be released from the canaliculus, for example, manually.

[0214] In certain embodiments, the implant remains within the lacrimal canaliculus for up to about 2 weeks, about 1 month, or up to about 2 months, or up to about 3 months, or up to about 4 months after administration.

[0215] In certain embodiments, the systemic concentration of antibiotics such as besifloxacin after administration of the insert of the present invention is very low, e.g., below quantifiable levels, which significantly reduces the risk of drug-drug interactions or systemic toxicity, which can be beneficial, for example, for elderly patients who frequently suffer from eye diseases and who also take other medications.

[0216] In certain embodiments, the inserts of the present invention are placed within the canaliculus and therefore not on the surface of the eye, only a single dose is required to provide for extended release of antibiotic as disclosed herein, and the inserts do not interfere or do not substantially interfere with contact lenses, thereby making them particularly suitable and convenient for patients who wear contact lenses.

[0217] In certain embodiments, patients treated with the present inserts require treatment of ocular infections prior to cataract and refractive surgery in order to improve the outcome / satisfaction of such surgery.

[0218] In certain embodiments, patients treated with the inserts of the present invention require short-term treatment of signs and symptoms of eye infection following cataract or refractive surgery.

[0219] In certain embodiments of the invention, while a first sustained release biodegradable intracanalicular insert is still retained within the canaliculus (either while the first insert is still releasing antibiotic or after the antibiotic in the first insert has been completely depleted or after the antibiotic in the first insert has been partially depleted, at least about 70%, or at least about 80%, or at least about 90%, and / or the first insert has released less antibiotic than initially after administration), an additional sustained release biodegradable intracanalicular insert is administered into the canaliculus through a lacrimal punctum of the eye (this procedure is called "insert stacking" or "stacking" for short).

[0220] In certain embodiments, stacking of inserts allows for long-term treatment with an antibiotic such as besifloxacin, hi certain embodiments, stacking of inserts provides release of a therapeutically effective amount of antibiotic for a total period of up to about 14 days, or up to about 28 days, or up to about 42 days, or up to about 50 days, or up to about 2 months after administration of the first insert.

[0221] kit In certain embodiments, the present invention further relates to kits comprising one or more insert(s) disclosed herein or produced according to the methods disclosed herein.

[0222] In certain embodiments, the kit comprises one or more sustained release biodegradable intracanalicular insert(s) disclosed herein. In certain embodiments, the kit further comprises instructions for using the one or more sustained release biodegradable intracanalicular insert(s). The instructions for using the one or more sustained release biodegradable intracanalicular insert(s) may be in the form of an operating manual for a physician to administer the insert(s). The kit may further comprise a package insert having product-related information.

[0223] In certain embodiments, the kit may further comprise one or more means for administering one or more sustained release biodegradable intracanalicular insert(s). The administration means may be, for example, one or more suitable tweezers(s) or forceps, for single use or repeated use. For example, suitable forceps are blunt (no teeth). The administration means may also be an injection device, such as a syringe or applicator system.

[0224] In certain embodiments, the kit may further include an ophthalmic dilator to dilate the punctum prior to administration of one or more sustained release biodegradable intracanalicular insert(s), thereby facilitating insertion of the insert(s) through the punctum and into the canaliculus. The dilator may also be combined / integrated with a forceps or applicator, for example, such that one end of the device is a dilator and the other end of the device is suitable for administering an insert. Alternatively, the kit may also contain a modified applicator, for example, with a tapered tip that can be used for both dilation and insertion.

[0225] In certain embodiments, one or more sustained release biodegradable intracanalicular insert(s) are individually packaged for single administration. In certain embodiments, one or more sustained release biodegradable intracanalicular insert(s) are individually packaged for single administration by securing each insert in a foam carrier sealed in a foil pouch. The foam carrier may have, for example, a V-shaped notch or a circular cut with an opening at the bottom of the V-shaped notch, for holding the insert.

[0226] When the kit contains more than one sustained release biodegradable intracanalicular insert, the inserts may be the same or different and may contain the same or different doses of an antibiotic, such as besifloxacin.

[0227] In addition to the above disclosure, the following other embodiments are also disclosed herein. EXAMPLES

[0228] The following examples are included to demonstrate certain aspects and embodiments of the claimed invention, however, those of ordinary skill in the art should understand that the following description is illustrative only and should not be construed as limiting the invention in any way.

[0229] Example 1: Preparation of besifloxacin insert Manufacturing process for besifloxacin intracanalicular insert Conversion to micronized besifloxacin base In the manufacture of besifloxacin insert, the first step of the process is to convert besifloxacin hydrochloride to the solid form of free base by the addition of base. In a controlled environment, besifloxacin hydrochloride is dissolved in water, then 1N NaOH is added dropwise with stirring to a pH of about 10.2, then 1N HCl is added dropwise to adjust to pH 9.8. The resulting suspension is allowed to stir for 2 hours. The precipitated besifloxacin free base is collected on a filter paper by vacuum filtration, washed with water for injection (WFI), removed, and vacuum dried overnight at room temperature in a vacuum chamber protected from light. Besifloxacin base is stored in refrigerated conditions in amber glass vials under nitrogen atmosphere.

[0230] Analysis of multiple development batches of besifloxacin free base shows consistency in yield between batches and, by XRPD, shows agreement of the crystal structure of the hydrochloride salt form.

[0231] Micronized besifloxacin base (see figure below) was analyzed for particle size distribution by laser light scattering in the Ocular, assay and purity by HPLC, and by Karl Fischer USP <921> The particles were analyzed intraocularly for water content according to the method of claim 1. The particle sizes of representative batches converted to base form are given in the table below. [Table 1]

[0232] Preparation of besifloxacin hydrogel inserts The formulation process is carried out by preparing a syringe containing trilysine acetate / NHS-fluorescein / disodium phosphate and a syringe containing besifloxacin / PEG-SG / monosodium phosphate. The two syringes are combined and then mixed to create a hydrogel / besifloxacin suspension, which is cast into a tube, cured, stretched, dried, and cut to length prior to packaging and sterilization.

[0233] Four-arm polyethylene glycol is synthesized from a core molecule of pentaerythritol, resulting in four polyethylene glycol chains per molecule with an approximate molecular weight of about 20,000 Da. The hydroxyl end groups of PEG (one on each arm) are esterified with a linear α,ω-dicarboxylic acid end group. Each terminal carboxylic acid is esterified with an N-hydroxysuccinimidyl (NHS) leaving group of reactive 4-arm 20K PEG SG (succinimidyl glutarate). This activated ester provides a site for reaction with the amino groups on trilysine to form the hydrogel network. In a similar mechanism, a small portion of the reactive amines on trilysine are covalently reacted with NHS-fluorescein prior to crosslinking of the hydrogel network, allowing fluorescent visualization of the hydrogel in the final product using blue light and yellow filters.

[0234] Preparation of trilysine acetate / NHS-fluorescein (TLA / FL) syringes (Part A) TLA / FL syringes are a combination of trilysine acetate, NHS fluorescein, and disodium phosphate solution. The bulk solution is prepared by mixing the components for a controlled period of time under basic pH conditions and allowing to react at room temperature for 1-24 hours.

[0235] Preparation of Besifloxacin / PEG (Besi / PEG) Syringes (Part B) Two separate syringes are prepared, which are then combined to create the besifloxacin / PEG-SG syringe used to fabricate the hydrogel. The first syringe contains a suspension of sieved micronized besifloxacin in water. The second syringe contains a PEG-SG solution in monobasic sodium phosphate buffer. The besifloxacin suspension syringe is then connected to the PEG-SG syringe with a Luer connector and the contents of the syringes are pumped back together until mixed. The suspension is then transferred to the two syringes, forming the besifloxacin / PEG-SG syringe.

[0236] Hydrogel Mixing and Casting To form the hydrogel / besifloxacin suspension, the TLA / FL syringe (part A) and the besifloxacin / PEG-SG syringe (part B) are connected with a Luer connector. The contents of the syringes are mixed together until combined, producing a reactive suspension of hydrogel / besifloxacin, which is transferred to one syringe. The hydrogel precursor / besifloxacin suspension syringe is then connected to the barb fitting of the tubing, and the suspension is injected into the tubing. Typical tubing diameters utilized are 2.0-2.2 mm, but may be adjusted as needed to produce insets of different diameters that have dried and / or absorbed moisture. Once the tubing is full, the tubing is removed from the syringe and the barb fitting of the tubing is capped. The remaining pieces of tubing are then filled in a similar manner. At this point, the filled tube containing the hydrogel / besifloxacin suspension is referred to as a cast strand. The formulation and casting process is repeated as necessary to prepare the desired number of strands per batch. The cast strands are then aligned vertically and stored for approximately 2 to 24 hours to allow the gel to fully react (harden).

[0237] Stretching and drying An incubator set at approximately 32.0°C with nitrogen flow is used for drying. Once the curing time has elapsed, the cast strand is placed in a tension fixture and clamped in place with a dynamic clamp. The cast strand is stretched in the tension fixture to approximately 2.5 times the original tube length. The tension fixture is then transferred to the incubator for approximately 3 days (or until the strand is completely dry) before being removed and cut.

[0238] Cutting and Inspection After the drying time has elapsed, the stretching fixture with the dried strands is removed from the incubator. The tube containing the cast strands is cut from the stretching fixture. The dried strands are removed from the tube. The strands are processed through a cutter and cut into lengths of approximately 2.5 mm. The cut inserts are stored in vials under nitrogen until packaging.

[0239] Packaging and Container Closure Systems The inserts are placed into a foam carrier and sealed in a heat sealable, low vapor permeable, aluminum-LDPE laminate foil pouch (Amcor Dessiflex™) impregnated with a desiccant under a nitrogen environment. The pouched inserts are terminally sterilized by gamma irradiation. The packaged product is stored under refrigerated conditions at 2°C to 8°C. A schematic diagram of the packaging configuration is shown in Figure 1.

[0240] Example 2 - Besifloxacin Insert Used in a Beagle Pharmacokinetic Study The inserts were formulated to contain approximately 0.45 mg of besifloxacin with a dry diameter of 0.59 mm and a length of 2.49 mm. After 24 hours of hydration in PBS (pH 7.4) at 37° C., the inserts hydrated to a diameter of 1.84 mm and shortened to a length of 2.37 mm. Key variables covering formulation, casting / stretching variables, packaging, and sterilization, along with dimensions and mass output, are listed in the table below. [Table 2]

[0241] These inserts were evaluated in a 42-day pharmacokinetic study in beagle dogs to assess the drug release profile of besifloxacin into tears. On day 0, hydrogel besifloxacin intracanalicular inserts were placed on both sides of the lower canaliculus in 20 beagle dogs. After visual confirmation of the presence of the inserts in the canaliculus, tears were collected from the eyes (n=10) using pre-cut 10 mm Schirmer strips at 0.5, 1, 2, 4, and 8 hours and at 1, 3, 7, 10, 14, 21, 28, 35, and 42 days after insertion. Tear samples were analyzed for besifloxacin by liquid chromatography tandem mass spectrometry.

[0242] The mean besifloxacin levels in tear samples after insertion are presented in the figure below. The release profile of the drug showed sustained release for approximately 14 days, followed by a gradual taper over time and near complete disappearance from tear measurements by the completion of the study. See Figure 4.

[0243] The area under the curve / minimal inhibitory concentration (AUC / MIC) is considered the best predictor of killing based on in vitro time-kill studies for fluoroquinolones [Nielsen et al., 2011; Mueller, 2004] and clinical efficacy [Khimdas et al., 2011], with an AUC / MIC of at least 100 being the best predictor of killing. 90 Values ​​are generally required for prediction of bacterial and clinical efficacy [Wright, 2000]. MICs for the four most common pathogens (Haemophilus influenzae (26.0%), Streptococcus pneumoniae (22.8%), Staphylococcus aureus (14.4%), and Staphylococcus epidermidis (8.4%)) in three studies supporting 0.6% besifloxacin ophthalmic solution [Hass, 2011]. 90 The AUC value [Proksch, 2009] was used together with the OTX-BFI PK data to estimate the AUC 0-24 / MIC 90 The results showed that AUC values ​​of over 100 were obtained for H. influenzae, S. aureus, S. epidermis, and S. pneumoniae. 0-24 / MIC 90 The results showed that besifloxacin concentrations released from OTX-BFI persisted in tears of beagle dogs for 21 days, suggesting that the inserts produced bactericidal levels of besifloxacin against common ocular isolates from conjunctivitis. [Table 3]

[0244] A hydrogel-based intracanalicular insert containing besifloxacin produced clinically effective drug levels capable of killing the most common isolates from bacterial conjunctivitis for 21 days. A single-dose intracanalicular insert of besifloxacin may reduce the need for patients to self-administer antibacterial therapy.

[0245] the purpose Topical ophthalmic antibiotics are often prescribed for antibacterial prophylaxis after ocular surgery or for the treatment of bacterial conjunctivitis. Sustained release delivery of antibiotics may overcome some of the limitations of topical therapy, such as reliance on patient self-administration. Herein, we evaluate the pharmacokinetics of besifloxacin 0.45 mg delivered from a biodegradable hydrogel intracanalicular insert in a canine model.

[0246] method On day 0, hydrogel besifloxacin intracanalicular inserts were placed bilaterally into the inferior canaliculus of 20 beagle dogs. After visual confirmation of the presence of the inserts in the canaliculus, tears were collected from the eyes (n=10) using pre-cut 10 mm Schirmer strips at 0.5, 1, 2, 4, 8 hours and at 1, 3, 7, 10, 14, 21, 28, 35, and 42 days after insertion. Tear samples were analyzed for besifloxacin by liquid chromatography tandem mass spectrometry. Remaining inserts were removed from the animals on day 42 and analyzed for drug content.

[0247] result The mean besifloxacin levels in tear samples after insertion are presented in Figure 1. The mean besifloxacin levels in tear samples gradually decreased over time and were cleared from tears in 35 to 42 days. The AUC / MIC values ​​for H. influenzae, S. aureus, S. epidermis, and S. pneumoniae were all above 100 over the 21-day period, indicating that the insert produced bactericidal levels of besifloxacin against common ocular isolates from conjunctivitis.

[0248] conclusion A hydrogel-based intracanalicular insert containing besifloxacin produced clinically effective drug levels capable of killing the most common isolates from bacterial conjunctivitis for 21 days. A single-dose intracanalicular insert of besifloxacin may reduce the need for patients to self-administer antibacterial therapy.

Claims

1. A sustained-release biodegradable intraocular insert comprising a hydrogel and 0.01 to 0.8 mg of besifloxacin or a pharmaceutically acceptable salt thereof, wherein the besifloxacin is dispersed within the hydrogel.

2. 10. The sustained-release biodegradable insert of claim 1, wherein the insert provides release of a therapeutically effective amount of besifloxacin for a period of up to one month after administration.

3. 2. The sustained-release biodegradable intraocular insert of claim 1, wherein the besifloxacin is besifloxacin base.

4. The sustained-release biodegradable intraocular insert of claim 1 , wherein the insert is an intracanalicular insert.

5. 10. The sustained-release biodegradable intraocular insert of claim 1, wherein the insert is cylindrical or essentially cylindrical and has a length in a dry state of less than 3.0 mm.

6. 2. The sustained-release biodegradable intraocular insert of claim 1, wherein the insert is cylindrical or essentially cylindrical, and upon absorption of water (after 24 hours in phosphate buffered saline at pH 7.2 at 37°C), the diameter of the insert increases and the length of the insert decreases.

7. 7. The sustained-release biodegradable intraocular insert of claim 6, wherein the ratio of the diameter of the insert in a hydrated state to the diameter of the insert in a dry state is in the range of 1.5 to 4.

8. 2. The sustained-release biodegradable intraocular insert of claim 1, wherein the insert is cylindrical or essentially cylindrical and has a length-to-diameter ratio greater than 1 or greater than 1.2 in a water-absorbed state (after 24 hours in phosphate-buffered saline at 37°C and pH 7.2).

9. 2. The sustained-release biodegradable intraocular insert of claim 1, having a total weight in the range of 50 to 1200 μg.

10. 10. The sustained-release biodegradable intraocular insert of claim 1, wherein the insert provides release of a therapeutically effective amount of besifloxacin for 12 hours or more after administration.

11. 10. The sustained-release biodegradable intraocular insert of claim 1, wherein the insert is biodegraded within 1 month, or 2 months, or 3 months, or 4 months after administration.

12. 2. The sustained-release biodegradable intraocular insert of claim 1, wherein the hydrogel comprises a polymer network comprising one or more units of polyalkylene glycol, polyethylene glycol (PEG), polyalkylene oxide, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, poly(vinylpyrrolidone), polylactic acid, polylactic-co-glycolic acid, random or block copolymers, or any combination or mixture thereof, or one or more units of polyamino acids, glycosaminoglycans, polysaccharides, or proteins.

13. 2. The sustained release biodegradable intraocular insert of claim 1, wherein the insert is an intracanalicular insert, contains 0.01 mg to 0.8 mg of besifloxacin, is cylindrical or essentially cylindrical, and the hydrogel comprises crosslinked 4a20k PEG units, wherein the crosslinks between the PEG units comprise groups represented by the following formula: 【Chemistry 1】 (wherein m is 2).

14. 2. The sustained release biodegradable intraocular insert of claim 1, wherein the insert is an intracanalicular insert, contains 0.05 mg to 0.45 mg of besifloxacin, is cylindrical or essentially cylindrical, has a diameter in the range of 0.5 mm to 0.7 mm and a length in the range of 2.0 mm to 3.0 mm in a dry state, and has a diameter in the range of 1.5 mm to 2.0 mm in a hydrated state (after 24 hours in phosphate buffered saline at 37° C., pH 7.2) and a length to diameter ratio of greater than 1, and the hydrogel comprises crosslinked 4a20k PEG units, and the crosslinks between the PEG units comprise groups represented by the following formula: 【Chemistry 2】 (wherein m is 2).

15. The sustained-release biodegradable intraocular insert of claim 1 , which contains a visualization agent.

16. 16. The sustained-release biodegradable intraocular insert of claim 15, wherein the visualization agent is a fluorophore such as fluorescein.

17. 10. The sustained-release biodegradable intraocular insert of claim 1, wherein the insert is free or substantially free of antimicrobial preservatives.

18. A sustained-release biodegradable intraocular insert as described in any one of claims 1 to 17 for use in a method for treating an ocular infection comprising administering to a patient a sustained-release biodegradable intraocular insert as described in any one of claims 1 to 17.

19. 18. The sustained-release biodegradable intraocular insert of any one of claims 1 to 17 for use in a method for treating an eye infection in a patient in need thereof, said method comprising intracanalicularly administering to said patient a sustained-release biodegradable intraocular insert comprising a hydrogel and besifloxacin, wherein besifloxacin particles are dispersed within said hydrogel.

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