Microemulsion pharmaceutical composition for treating anterior segment diseases of eyes

Abstract

The present invention relates to an oil-in-water microemulsion which has been proved to be a suitable drug depot system for the treatment of anterior ocular diseases, wherein the disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gel-drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves eye disease, Szifen syndrome (SJS), silkworm-erosive corneal ulceration and corneal transplant rejection, more particularly neovascularization disease (NV). The microemulsion according to the present invention is indeed capable of efficiently delivering and maintaining a high concentration of an active ingredient in the anterior segment of the eye after administration.

Description

Technical Field

[0001] The present invention relates to an oil-in-water microemulsion, which has been proven to be a suitable drug reservoir system for treating anterior segment diseases, particularly corneal diseases, more particularly corneal neovascularization diseases (NV). The microemulsion according to the present invention is indeed able to effectively deliver and maintain a high concentration of active ingredients in the anterior segment of the eye after administration, thus providing an effective drug reservoir system. Background Art

[0002] The anterior segment refers to the front-most area of ​​the eye, including the bulbar conjunctiva, conjunctiva, cornea, and sclera.

[0003] Treatments directed to diseases of this portion of the eye require that ophthalmically active ingredients be delivered and retained in that portion of the eye at effective concentrations and for a suitable period of time to produce their therapeutic effect.

[0004] At the same time, the barriers and drug elimination pathways in the anterior segment of the eye display unique properties, which make it difficult to maintain high concentrations of active ingredients after administration.

[0005] In fact, due to "blinking" and different mechanisms used for elimination, it is known that topically applied eye drops are eliminated from the nasolacrimal duct two minutes after instillation, and usually only 60% of the instilled amount remains on the ocular surface. (Clotilde J. Et al. J Control Release. 2020 May 10; 321: 1-22. oi:10.1016 / j.jconrel.2020.01.057. Page 2, second paragraph)

[0006] In this context, for example, the treatment of corneal diseases is one of the major and most challenging areas of research due to the special properties and characteristics of the ocular surface. The healthy cornea is actually a transparent avascular tissue located in front of the iris and pupil. The cornea is unique in that it is completely avascular and lymphatic, which is essential for its clarity and optimal vision. Therefore, maintaining transparency and avascularity is essential to maintain optimal vision and protect the eye from infection and structural damage.

[0007] Abnormal new blood vessels can invade the corneal stroma from pre-existing pericorna structures as the balance of angiogenic and anti-angiogenic factors that normally maintain corneal transparency is disrupted, leading to subsequent corneal neovascularization. This is caused by a variety of ocular insults, including infection, inflammation, ischemia, degeneration, trauma, and loss of the limbal stem cell barrier.

[0008] When blood vessels and lymphatic vessels from the pericorneal vascular plexus grow into the cornea, pathological conditions known as corneal angiogenesis and corneal lymphangiogenesis, respectively, result.

[0009] Vasculogenesis involves the de novo formation of blood vessels from vascular endothelial precursor cells (ie, hemangioblasts and angioblasts) that are derived from mesodermal precursors (via mesoderm induction).

[0010] In contrast, angiogenesis is a process in which endothelial cells of pre-existing blood vessels proliferate and form new blood vessels. In corneal neovascularization diseases, the endothelial cells of the newly formed corneal blood vessels are derived from pre-existing limbal blood vessels (i.e., angiogenesis). However, pericytes (another key cell type in blood vessel formation) are derived from bone marrow-derived precursor cells (i.e., vasculogenesis). Ozerdem and colleagues believe that both angiogenesis and vasculogenesis are involved in NV, and targeting these two mechanisms will be the most effective way to treat this disease (Danial Roshandel et al. OculSurf. 2018 October; 16(4): 398-414).

[0011] Corneal lesions that can lead to neovascularization include lipid keratopathy, corneal ulcers and scars, herpetic eye disease, infectious keratitis, chemical burns, transplant rejection, and hypoxic damage caused by wearing contact lenses. Corneal neovascularization is a vision-threatening disease and a growing public health problem. One study reported an estimated incidence of 1.4 million people per year, of whom 12% subsequently suffered blindness. In addition, 20% of corneal samples taken from corneal transplant surgeries showed evidence of corneal neovascularization (Sharif Zuhair et al. Romanian Journal of Ophthalmology, Volume 63, Issue 1, January-March 2019).

[0012] Currently, treatments for NV include surgery and corticosteroids and NSAIDs as effective inhibitors of inflammation, and immunomodulators such as cyclosporine and tacrolimus for ocular surface immune diseases. Tocilizumab is an IL-6 receptor antagonist that effectively reduces NV in animal models by reducing corneal inflammation and VEGF expression. TNF-α inhibitors have been used in experimental studies because of their simultaneous anti-inflammatory and anti-angiogenic activities. Infliximab is an anti-TNF-α monoclonal antibody.

[0013] Preclinical studies of the anti-VEGF family have been conducted recently, but to date there are no approved therapies for NV. Among the anti-VEGF agents, aflibercept, pegaptanib, and bevacizumab have been initially approved for use in a variety of cancers due to their antiangiogenic properties and are used (off-label) to treat ocular angiogenesis, including NV.

[0014] So far, the only topical antiangiogenic drug in phase II and III trials is aganirsen, an antisense oligonucleotide that inhibits NV by blocking the expression of insulin receptor substrate-1 (IRS-1) and downregulating the expression of VEGF and IL-1β (Danial Roshandel et al. Ocul Surf. 2018 October; 16(4): 398-414).

[0015] Despite extensive efforts, there is still no standard procedure for NV treatment.

[0016] Therefore, there is a great need to improve current treatments for NV as well as other anterior segment diseases, especially corneal diseases. Summary of the invention

[0017] It is therefore an object of the present invention to provide new and improved methods of treatment for diseases of the anterior segment of the eye, among which in particular corneal diseases, such as corneal neovascularization disease (NV). In particular, it is an object of the present invention to provide oil-in-water microemulsions that are able to effectively deliver and maintain high loads of ophthalmically active ingredients in the anterior segment of the eye for a prolonged period of time for the treatment of diseases, in particular NV. In this way, the present invention provides an effective ophthalmic drug reservoir system for the anterior segment of the eye.

[0018] The Applicant has indeed surprisingly found that the oil-in-water microemulsion object of the present invention allows absorption of ophthalmically active ingredients in the anterior segment of the eye and maintains unexpectedly high concentrations of the active ingredient even for a long time after application (ie up to 120 minutes after application).

[0019] Thus, in a first aspect of the invention, the present invention relates to an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, globulin-shaped corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0020] In a preferred embodiment, the present invention relates to an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system, preferably for treating at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably for treating the cornea, even more preferably for treating corneal neovascularization disease (NV).

[0021] It is noteworthy that in the first embodiment of this aspect of the invention, the present invention relates to an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, the oil-in-water microemulsion comprising:

[0022] an oil component, wherein the oil component is present in an amount of 0.4% to 1.4% weight / volume (w / v) of the microemulsion;

[0023] an aqueous component, wherein the content of the aqueous component is 55.85% w / v to 75.70% w / v of the microemulsion;

[0024] a surfactant or a mixture of a surfactant and a co-surfactant, wherein the surfactant or the mixture of a surfactant and a co-surfactant is present in an amount of 5.71% w / v to 22.82% w / v of the microemulsion;

[0025] The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0026] In this first embodiment, the oil-in-water microemulsion is used as an anterior segment ocular drug reservoir system, preferably for treating at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably for treating the cornea, and even more preferably for treating NV.

[0027] Advantageously, the combination of the components and their weight / volume composition allow the microemulsion according to the invention to achieve a finely dispersed system consisting of a lipid phase and an aqueous phase with very small particles, on average less than 30 nm, typically less than or equal to 15 nm, and a very narrow distribution of particle sizes, typically about 15±10 nm.

[0028] Therefore, in a second embodiment of the first aspect of the present invention, the present invention also relates to an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the average particle size is less than 30 nm, the oil-in-water microemulsion comprising:

[0029] a lipid phase comprising an oil component, one or more surfactants and one or more co-surfactants, and

[0030] A water phase comprising one or more surfactants and one or more co-surfactants, wherein:

[0031] The weight / volume ratio of the content of surfactant and co-surfactant in the lipid phase to the content of surfactant and co-surfactant in the aqueous phase is 2 to 10; and

[0032] The weight / volume ratio of the content of the oil component in the lipid phase to the content of the surfactant and the co-surfactant in the aqueous phase is 0.2 to 0.4;

[0033] The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0034] In this second embodiment, the oil-in-water microemulsion is used as an anterior segment ocular drug reservoir system, preferably for treating at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably for treating the cornea, and even more preferably for treating corneal neovascularization disease (NV).

[0035] The advantages of the microemulsion according to this second embodiment have already been disclosed in the first embodiment of the first aspect of the present invention and are therefore not repeated.

[0036] Due to the unexpected ability to deliver ophthalmically active ingredients to the anterior segment of the eye and maintain high concentrations of the active ingredients on the anterior segment of the eye even for a long time after application, the oil-in-water microemulsion of the present invention is particularly effective as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, jellydrop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection, especially corneal neovascularization disease (NV).

[0037] Therefore, in another aspect of the present invention, the present invention also relates to a pharmaceutical composition for treating anterior segment diseases of the eye, which comprises at least one ophthalmically active ingredient in an oil-in-water microemulsion according to the present invention, wherein the disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, glottoid corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0038] In this further aspect, the pharmaceutical composition is for treating anterior segment diseases of the eye, preferably treating at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably treating the cornea, even more preferably treating NV.

[0039] The advantages of the pharmaceutical composition according to this aspect of the invention have already been disclosed with reference to the microemulsion according to the invention and are therefore not repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In the attached picture:

[0041] Figure 1 (AD) depicts stability data for recovery assays, zeta potential (pZ), mean particle size distribution, pH, polydispersity index (PDI), and mean particle size distribution (size) at 25°C for various periods of time (up to 24 months);

[0042] Figure 2 (AE) describes stability data for recovery determination, zeta potential (pZ), mean particle size distribution, pH, polydispersity index (PDI), and mean particle size distribution (size) at various temperatures, 5°C, 25°C, and 40°C, for various periods of time (up to 36 months); and

[0043] Figure 3 (AC) depicts the concentrations of sorafenib in cornea, conjunctiva, vitreous, sclera, retina, and plasma tissues at different time points after single-dose administration to NZW rabbits. DETAILED DESCRIPTION

[0044] In a first aspect, the present invention relates to an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, globulin-shaped corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection, and the disease is especially corneal neovascularization disease (NV).

[0045] Applicants have surprisingly found that the oil-in-water microemulsions object of the present invention allow absorption of ophthalmically active ingredients, including sorafenib, in the anterior segment of the eye and maintain unexpectedly high concentrations of the active ingredient even for a long time after administration (up to 120 minutes after administration).

[0046] Due to the unexpected ability to deliver ophthalmically active ingredients to the anterior segment of the eye and to maintain high concentrations of the active ingredients on the anterior segment of the eye after application, the oil-in-water microemulsion according to the present invention is particularly effective as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the diseases are a group consisting of corneal neovascularization disease (NV), ocular melanoma, jelly drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection, and the diseases are especially corneal neovascularization disease (NV).

[0047] It is therefore an object of the present invention to provide new and improved methods of treatment for diseases of the anterior segment of the eye, particularly corneal neovascularization (NV). In particular, it is an object of the present invention to provide an oil-in-water microemulsion that is capable of effectively delivering ophthalmically active ingredients, particularly anti-angiogenic agents, to the anterior segment of the eye for the treatment of diseases, particularly corneal neovascularization (NV).

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those skilled in the art to which the present invention belongs, which are generally understood. Unless otherwise stated, all patents, patent applications, disclosed applications and publications, GenBank sequences, databases, websites and other disclosed materials mentioned in the entire disclosure of this article are incorporated herein by reference as a whole. If the term herein has multiple definitions, then the definition in this section shall prevail. When referring to URL or other such identifiers or addresses, it is understood that such identifiers can change, and specific information on the Internet can change, but equivalent information can be found by searching the Internet. The reference to this document proves the availability and public dissemination of such information.

[0049] As used herein, an emulsion is a system consisting of two immiscible liquid phases, which are intimately mixed and dispersed one in the other. An emulsion refers to a colloidal dispersion of two immiscible liquids, such as oil and water (or other aqueous liquids, such as polar solvents), one of which is part of the continuous phase and the other is part of the dispersed phase. The emulsion herein is of the oil-in-water type, which includes any oil-soluble phase dispersed in any aqueous phase (also referred to as the water phase), wherein the oil phase is the dispersed phase and the water phase is the continuous phase.

[0050] Emulsions are usually stabilized by one or more surfactants and / or emulsion stabilizers. Surfactants form an interfacial film between the oil and water phases of the emulsion, providing a metastable system.

[0051] As used herein, microemulsion is a system consisting of a finely dispersed lipid phase and an aqueous phase. A microemulsion is a transparent, isotropic and stable liquid mixture in which the lipid phase and the aqueous phase are combined by a surfactant (usually in combination with a cosurfactant). A microemulsion is a clear, thermodynamically stable, isotropic liquid mixture of oil, water and a surfactant and an optional cosurfactant.

[0052] Microemulsions are formed spontaneously when the aqueous component and the lipid component are mixed, optionally in the presence of one or more surfactants. Thus, a microemulsion is a thermodynamically stable system in which particles are dispersed in a continuous phase. The droplet size of the dispersed phase in a microemulsion is less than 100 nm, typically between 5 nm and 50 nm, inclusive.

[0053] As used herein, "surfactant" refers to synthetic and naturally occurring amphiphilic molecules having a hydrophobic portion and a hydrophilic portion. Surfactants contain a hydrophilic domain and a hydrophobic domain, i.e., an amphiphilic molecule. In view of their properties, surfactants promote the formation of oil-in-water emulsions, in which interaction with the aqueous phase and the oil phase is required for the existence of micelles. Due to their amphiphilic (amphiphilic, amphipathic) properties, surfactants and co-surfactants can reduce the surface tension between two immiscible liquids (e.g., emulsions, such as the oil phase and the aqueous phase in microemulsions), thereby stabilizing the emulsion.

[0054] Surfactants can be characterized based on their relative hydrophobicity and / or hydrophilicity. For example, relatively lipophilic surfactants are more soluble in fats, oils, and waxes, typically having a hydrophobic-lipophilic balance (HLB) value of less than or about 10, while relatively hydrophilic surfactants are more soluble in aqueous compositions, such as water, typically having an HLB value of greater than or about 10. Relatively amphiphilic surfactants are soluble in oil-based and water-based liquids, typically having an HLB value of close to or about 10. Surfactants used in the compositions herein are biocompatible and have an HLB value of between at or about 8 and at or about 16, typically 10-16 or 12-14.

[0055] As used herein, a co-surfactant is a surfactant that further reduces the surface tension of a liquid in addition to another surfactant. A microemulsion containing a surfactant refers to a surfactant and a co-surfactant. Co-surfactants are hydrophilic in nature and reduce the surface tension of water. They are commonly used as wetting agents, for example, to increase the spreading ability of aqueous fluids by reducing the surface tension of water. Co-surfactants are also used and often required to increase the solubility of the primary surfactant.

[0056] As used herein, "particle size" and "average particle size" refer synonymously to the average diameter of particles in a provided liquid, such as the droplet diameter or micelle diameter in an emulsion.

[0057] As used herein, "oil phase" or "lipid phase" is used to refer to the portion (or phase) of a composition, such as those provided herein, which contains one or more lipophilic and / or amphiphilic components, such as oil, which is typically a fat-soluble phase. In an oil-in-water (o / w) microemulsion, the lipid phase is typically the dispersed phase, while water is the dispersion phase.

[0058] As used herein, oil phase ingredients refer to components of the provided compositions that are included in the oil phase in the provided methods for preparing the compositions. Typical oil phase ingredients include non-polar compounds, such as non-polar active ingredients; at least one surfactant; oil (e.g., non-polar solvent); preservative; and microemulsion stabilizer. Other lipophilic and / or amphiphilic ingredients may be included in the oil phase.

[0059] As used herein, "water phase (water phase, aqueous phase)" refers to a portion (phase) of a composition, such as those provided herein, which contains one or more hydrophilic components and / or amphiphilic components (water phase components), and is generally a water-soluble phase. Typically, in the microemulsion composition provided herein, the water phase is a continuous phase. "Water phase" is also used to refer to a liquid containing water phase components produced when a microemulsion is prepared. As used herein, the water phase component refers to a component of a composition contained in the water phase in the method for preparing the composition provided. Typical water phase ingredients may include, but are not limited to, polar solvents, typically polar protic solvents (e.g., water and alcohols), typically alcohols having more than one hydroxyl group (e.g., dihydric alcohols and trihydric alcohols, such as glycerol and propylene glycol); at least one surfactant; a preservative; and an emulsion stabilizer. Other hydrophilic and / or amphiphilic components may be contained in the water phase.

[0060] As used herein, the thermodynamic stability of a microemulsion refers to the stability of the dispersion such that the phases do not separate. The microemulsions provided herein exhibit high thermodynamic stability, as evidenced by their stability at elevated temperatures.

[0061] As used herein, a subject includes an animal, typically a mammal, usually a human.

[0062] As used herein, room temperature and ambient temperature are used to describe the temperature prevailing in one or more enclosed spaces where humans are typically located or inhabited. Room temperature can vary, but generally refers to a temperature between at or about 19° C. and at or about 25° C. When the composition is stored at room temperature, it should be understood that the temperature is generally maintained within or about this range.

[0063] As used herein, refrigeration temperature refers to temperatures commonly found in refrigerators (e.g., household or restaurant refrigerators), e.g., temperatures lower than room temperature, but generally a few degrees above the freezing point of water (0° C. or about 0° C., or -19° C. or -20° C.). Typically, refrigeration temperatures are between about 10° C. or about 10° C. and 0° C. or about 0° C., e.g., 4° C. or about 4° C. When the composition is stored at refrigeration temperature, it should be understood that it is maintained at a temperature commonly found in household or industrial refrigerators.

[0064] As used herein, freezing temperatures refer to temperatures near or below the freezing point of water, such as temperatures typically used in domestic refrigerators, such as 0°C or about 0°C, such as -19°C or about -20°C or about -20°C, or colder.

[0065] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context dictates otherwise.

[0066] As used herein, ranges and quantities can be expressed as "about" specific values ​​or ranges. "About" also includes exact quantities. Therefore, "about 5 grams" means "about 5 grams" and also means "5 grams". It should also be understood that the ranges expressed herein include integers and fractions thereof within the range. For example, the range between 5 grams and 20 grams includes integer values ​​of, for example, 5 grams, 6 grams, 7 grams, 8 grams, 9 grams, 10 grams, 11 grams, 12 grams, 13 grams, 14 grams, 15 grams, 16 grams, 17 grams, 18 grams, 19 grams, and 20 grams, and fractions within the range, such as, but not limited to, 5.25 grams, 6.72 grams, 8.5 grams, and 11.95 grams.

[0067] As used herein, "optional" or "optionally" means that the subsequently described event or circumstance occurs or does not occur, and the description includes instances where the event or circumstance occurs and instances where it does not occur. For example, an optional variant portion means that the portion is a variant or a non-variant. In another embodiment, an optional ligation step means that the process includes a ligation step or does not include a ligation step.

[0068] As used herein, ranges and amounts may be expressed as "about" a particular value or range. "About" also includes the exact amount. Thus, "about 10%" means "about 10%" and also means "10%."

[0069] As used herein, "optional" or "optionally" means that the subsequently described event, circumstance, or element occurs or does not occur, and that the description includes instances where the event, circumstance, or element occurs and instances where it does not occur. For example, an optionally substituted group means that the group is unsubstituted or substituted.

[0070] The present invention may, in one or more of its aspects and embodiments, exhibit one or more of the features disclosed hereinafter.

[0071] The oil-in-water microemulsion according to the present invention comprises an oil component, an aqueous component and a surfactant or a mixture of a surfactant and a co-surfactant, and the components form a finely dispersed two-phase system consisting of a lipid phase and an aqueous phase.

[0072] According to a first embodiment of the microemulsion of the present invention, there is provided an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, the oil-in-water microemulsion comprising:

[0073] an oil component, wherein the oil component is present in an amount of 0.4% to 1.4% weight / volume (w / v) of the microemulsion;

[0074] an aqueous component, wherein the content of the aqueous component is 55.85% w / v to 75.70% w / v of the microemulsion;

[0075] a surfactant or a mixture of a surfactant and a co-surfactant, wherein the surfactant or the mixture of a surfactant and a co-surfactant is present in an amount of 5.71% w / v to 22.82% w / v of the microemulsion;

[0076] The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0077] In this first embodiment, the oil-in-water microemulsion is used as an anterior segment ocular drug reservoir system, preferably for treating at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably for treating the cornea, and even more preferably for treating corneal neovascularization disease (NV).

[0078] Preferably, the oil-in-water microemulsion according to the present invention contains 0.4% weight / volume (w / v) to 1.4% weight / volume (w / v) of the oil component.

[0079] Preferably, the oil component comprises at least one oil. Advantageously, the oil is biocompatible.

[0080] Preferably, the oil is selected from natural oils or synthetic oils or mixtures thereof.

[0081] Preferably, suitable natural oils are selected from vegetable oils and / or animal oils, more preferably from the group consisting of soybean oil, corn oil, linseed oil, sunflower oil, krill oil, cod liver oil, fish oil, avocado oil, almond oil, babassu oil, borage oil, carob oil, cashew oil, grape seed oil, coconut oil, rice bran oil, castor oil, hemp seed oil, jojoba oil, peanut oil, poppy seed oil, sesame oil, walnut oil, olive oil, wheat germ oil, argan oil, cottonseed oil, black currant seed oil, and oils enriched with PUFAs in a fraction greater than 10%.

[0082] Preferably, the suitable synthetic oil is selected from the group consisting of medium-chain fatty acid esters and medium-chain triglycerides.

[0083] Preferably, the oil is a vegetable oil (eg coconut oil), or a medium-chain fatty acid ester (eg isopropyl myristate).

[0084] The oil component may also include other non-polar ingredients.

[0085] Preferably, the oil-in-water microemulsion according to the present invention comprises 55.85% weight / volume (w / v) to 75.70% weight / volume (w / v) of the aqueous component.

[0086] Preferably, the aqueous component comprises water and any other polar protic solvents and optionally co-surfactants and wetting agents used in the microemulsion according to the present invention.

[0087] Preferably, the oil-in-water microemulsion according to the present invention comprises 5.71% weight / volume (w / v) to 22.82% weight / volume (w / v) of surfactant and co-surfactant.

[0088] Preferably, the surfactant / co-surfactant according to the present invention is a non-ionic surfactant.

[0089] Preferably, the HLB of the surfactants and co-surfactants according to the present invention is from 8 to 16, for example wherein the HLB of each surfactant and co-surfactant is at least 10, more preferably from 10 to 16, even more preferably from 12 to 14.

[0090] Preferably, the oil-in-water microemulsion according to the present invention comprises one surfactant and a co-surfactant, or two surfactants and one co-surfactant, or two surfactants and two co-surfactants.

[0091] In some embodiments, the oil-in-water type microemulsion according to the present invention is formed by lipid and water, wherein the surfactant is identical, so the microemulsion of gained contains a kind of surfactant, and usually contains one or two co-surfactants.In other embodiments, the surfactant in every kind of phase is different.In some embodiments, the oil-in-water type microemulsion according to the present invention is formed by lipid component and aqueous component, wherein the water comprises surfactant and co-surfactant, and the lipid component comprises surfactant and co-surfactant.The co-surfactant in every kind of phase can be identical or different.

[0092] Typically, each phase of the microemulsion contains one surfactant and one co-surfactant. The surfactant and co-surfactant may be the same or different.

[0093] Technicians can easily select surfactants and co-surfactants for microemulsions. The selected surfactant will have an HLB within the necessary range and will be suitable for the intended application and activating agent. For example, an ophthalmic surfactant should be suitable for application to the eyes. Surfactants suitable for pharmaceutical compositions include ophthalmic surfactants. Such surfactants are well known (see, for example, U.S. Patent No. 6,267,985).

[0094] For example, in one embodiment, the lipid phase contains Tween 80 / propylene glycol as surfactant / co-surfactant and the aqueous phase contains Kolliphor RH40 / propylene glycol.

[0095] Preferably, the surfactant is selected from the group consisting of poloxamers, polyethylene glycolated fatty acids, polyoxyethylene, polyoxyethylene sorbitan fatty acid derivatives, polyoxyethylene, hydrogenated castor oil ethoxylates, fatty acid glycerides, polyethylene glycolated fatty acids, polyethylene glycol castor oil surfactants, poloxamers, amine oxides and alcohol ethoxylates (non-ionic). Exemplary surfactants are polyethylene glycol sorbitan monolaurate (polysorbate 20; TWEEN 20), polyethylene glycol sorbitan monooleate (polysorbate 80; TWEEN 80), and polyethylene glycol sorbitan monopalmitate (polysorbate 40; MONTANOX 40. In other embodiments, the surfactant is selected from polyethylene glycol 35 castor oil (CREMOPHOR EL, KOLLIPHOR EL), polyethylene glycol 40 hydrogenated castor oil (CREMOPHOR RH40; KOLLIPHOR RH40), PEG 40 castor oil (ETOCAS 40), PEG-60 hydrogenated castor oil (CRODURET 60), and polyethylene glycol 15-hydroxystearate (KOLLIPHOR HS15).

[0096] Preferably, the surfactant is nonionic. For example, the nonionic surfactant can be selected from Polysorbate (Tween TM ), lauryl dimethylamine oxide, polyethoxylated alcohol, polyethylene glycol lauryl ether, Polyoxyethylene castor oil, lecithin, poloxamer, polyethylene glycol, fatty acid glycerides. Preferably, the surfactant is selected from the group consisting of castor oil and hydrogenated castor oil ethoxylate.

[0097] Preferably, the co-surfactant comprises glycerol and / or propylene glycol.For example, each phase may comprise the same or different co-surfactants.

[0098] The oil-in-water microemulsion according to the present invention optionally comprises other ingredients, such as one or more isotonizing agents or tonicity agents, stabilizers, antioxidants, antimicrobial agents, thickeners, and branched and linear polymers.

[0099] Microemulsions according to the present invention may include, for example, a buffer to maintain the pH in a desired range, typically between about 5.0 and 8, such as between 5.2 and 8, such as 7.4 or 7.5. Exemplary suitable biocompatible buffers include, but are not limited to, tromethamine (Tris buffer, 2-amino-2-(hydroxymethyl)propane-1,3-diol), Mcllvaine (citrate-phosphate buffer), Sprensen (0.133M Na2HPO4; 0.133M KH2PO4 pH 7.2), sodium lactate, sodium acetate, sodium borate, boric acid, and imidazole. Exemplary buffers are histidine and citrate with NaOH or HCl to adjust the pH. Suitable buffer concentrations are in the range of 10-50 mM.

[0100] In the microemulsion according to the present invention, isotonic agents can be used to achieve the tension required in the preparation. Exemplary isotonic agents are glycerol, sorbitol, mannitol, sucrose, trehalose, propylene glycol, glucose, ethylene glycol, sodium chloride, potassium chloride, magnesium chloride and calcium chloride. In one embodiment, the microemulsion comprises excipients, such as stabilizers, antioxidants, antimicrobial agents, thickeners, side chains and straight chain polymers. Isotonic agents are used at a concentration of, for example, 100-400mOsmol / kg compositions (including 100mOsmol / kg and 400mOsmol / kg) to ensure that the osmotic pressure of the preparation is.

[0101] Stabilizers can be selected from, for example, glycine, proline, cyclodextrin, calixarene, hydroxypropylmethylcellulose, histidine, betaine, albumin, L-carnitine, taurine, glyceryl monostearate, pectin, polyvinyl alcohol, propylene glycol. It is within the skill of the art to determine a suitable concentration, depending on, for example, the particular stabilizer and other components of the composition. For example, the amount of stabilizer can be between 0.0001% w / v and 20% w / v, including 0.0001% w / v and 20% w / v.

[0102] The microemulsion according to the present invention may also include a thickener. Thickeners include, but are not limited to, thickeners extracted from plants, microorganisms, and animals. Many thickeners are known to those skilled in the art. An example of a thickener extracted from plants is viscose. Examples of thickeners are gums, for example those extracted from plants of the genera Cyamopsis, Sterculia, Ipomoea, Trigonella, Cassia, Physaria, Tamarindus, Ceratonia, Caesalpinia; exudates of plant origin, for example those associated with species belonging to the genera Manilkara, Amorphophallus, Acacia, Anogeissus, Sterculia, Astragalus; gums of microbial origin, for example dextran, gellan gum, xanthan gum, gum); extracts of marine origin, such as sodium alginate, alginic acid, carrageenan, agar, and derivatives of Ulvalactuca, Alga nori, Arthrospira platensis; derivatives of animal origin, such as chitin and chitosan, hyaluronic acid; derivatives of cellulose, such as carboxymethylcellulose (CMC), hydroxyethylcellulose, hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), microcrystalline cellulose (MCC).

[0103] Antioxidants can also be included in the microemulsion according to the present invention. Examples of antioxidants are alpha-tocopherol, flavonoids (e.g., resveratrol, epigallocatechin-3-gallate, quercetin, naringenin, delphinidin), coenzyme Q10, NDGA (nordihydroguaiaretic acid), meso-NDGA, sodium ascorbate, L-ascorbic acid, N-acetylsarcosine, citric acid, isoascorbic acid, L-6-ascorbyl palmitate, L-carnosine, L-glutathione, L-cysteine, cysteine ​​ascorbate. The amount of antioxidant can be determined by the technician. This depends on the specific antioxidant used and other components of the composition. An exemplary range is between 0.0001% w / v and 5.0% w / v, including 0.0001% w / v and 5.0% w / v.

[0104] Advantageously, the combination of the components and their weight / volume composition enable the microemulsion according to the invention to achieve a finely dispersed two-phase system consisting of a lipid phase and an aqueous phase with very small particles having an average size of less than 30 nm (usually less than or equal to 15 nm), and a very narrow distribution of particle sizes, typically about 15±10 nm.

[0105] Advantageously, the size distribution of the particles in the microemulsion is 15 nm ± 10 nm. Preferably, the polydispersity index (PDI) of the microemulsion is from 0.02 to 0.380, preferably from 0.02 to 0.2, more preferably from 0.02 to 0.15, more preferably less than 0.12, even more preferably less than 0.1.

[0106] Therefore, according to the second embodiment of the first aspect of the present invention, the present invention also relates to an oil-in-water microemulsion for use as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the average particle size is less than 30 nm, the oil-in-water microemulsion comprising:

[0107] a lipid phase comprising an oil component, one or more surfactants and one or more co-surfactants, and

[0108] A water phase comprising one or more surfactants and one or more co-surfactants, wherein:

[0109] The weight / volume ratio of the content of surfactant and co-surfactant in the lipid phase to the content of surfactant and co-surfactant in the aqueous phase is 2 to 5, preferably 2.2 to 4.7, more preferably 2.4-4.5; and

[0110] The weight / volume ratio of the content of the oil component in the lipid phase to the content of the surfactant and the co-surfactant in the aqueous phase is 0.2 to 0.4, preferably 0.22 to 0.38, more preferably 0.24 to 0.34;

[0111] The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0112] In this second embodiment, the oil-in-water microemulsion is used as an anterior segment ocular drug reservoir system, preferably for treating at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably for treating the cornea, and even more preferably for treating corneal neovascularization disease (NV).

[0113] The advantages, exemplary features and preferred features of the microemulsion according to this second embodiment have already been disclosed in the first embodiment of the microemulsion according to the present invention and are therefore not repeated.

[0114] Preferably, in the microemulsion according to this embodiment of the invention, in the lipid phase, the weight / volume ratio of the oily component to the surfactant and co-surfactant is from 0.05 to 0.75, more preferably from 0.07 to 0.55, even more preferably from 0.1 to 0.35.

[0115] The fine particle dispersion enables the microemulsions according to the invention to exhibit advantageous properties, including resulting in high thermodynamic stability.

[0116] Microemulsions according to the present invention can be prepared by combining a specific ratio of surfactants in aqueous and lipid (lipophilic) phases, typically but not limited to combining two surfactants (surfactant and cosurfactant) in each phase. When aqueous and lipophilic phases are mixed, a microemulsion is formed. The resulting microemulsion has very small particles, less than 30nm on average, usually less than or equal to 15nm, and has a very narrow particle size distribution, usually about 15 ± 10nm. Compared with similar emulsions in the prior art, the final properties of the emulsion include increased thermal stability and the high bioavailability of any drug prepared in the emulsion.

[0117] According to a preferred aspect of the present invention, in order to obtain advantageous properties, including a small particle size, the microemulsion according to the present invention can be obtained by combining (preferably mixing) a lipid phase containing an oil component and a surfactant and a co-surfactant; and an aqueous phase also containing a surfactant and a co-surfactant, wherein the weight / volume ratio of the surfactant / co-surfactant in the lipid phase to the surfactant / co-surfactant in the aqueous phase is 2 to 5.0, preferably 2.2 to 4.7, more preferably 2.4 to 4.5, and wherein the weight / volume ratio of the oil component in the lipid phase to the surfactant / co-surfactant in the aqueous phase is 0.2 to 0.4, preferably 0.22 to 0.38, more preferably 0.24 to 0.34.

[0118] Preferably, when the microemulsion according to the present invention is obtainable by the above-mentioned mixing method, in the lipid phase, the weight / volume ratio of the oil component to the mixture of surfactant / co-surfactant in the lipid phase is from 0.05 to 0.75, more preferably from 0.07 to 0.55, even more preferably from 0.1 to 0.35.

[0119] Preferably, when the microemulsion according to the present invention can be obtained by the above-mentioned mixing method, the content of the oil component is 0.4 to 1.4% (w / v) of the microemulsion, the content of the surfactant and the co-surfactant of the lipid phase is 4.0% to 18.67% (w / v) of the microemulsion; the content of the surfactant and the co-surfactant of the aqueous phase is 1.66% to 4.15% (w / v) of the microemulsion.

[0120] Preferably, in the lipid phase, the surfactant comprises at least one polyoxyethylene sorbitan fatty acid derivative and at least one polyethylene glycol castor oil surfactant, the co-surfactant comprises propylene glycol, and the weight ratio of surfactant:co-surfactant is 3:1.5, wherein preferably, in the surfactant, the ratio of polyoxyethylene sorbitan fatty acid derivative:polyethylene glycol castor oil surfactant is 1:2.

[0121] Preferably, in the aqueous phase, the surfactant comprises at least one polyethylene glycol castor oil surfactant, the co-surfactant comprises propylene glycol, and the ratio of surfactant:co-surfactant is 3:1.

[0122] Preferably, the polyoxyethylene sorbitan fatty acid derivative is selected from polyethylene glycol sorbitan monolaurate (polysorbate 20; TWEEN 20), polyethylene glycol sorbitan monooleate (polysorbate 80; TWEEN 80) and polyethylene glycol sorbitan monopalmitate (polysorbate 40; MONTANOX 40), more preferably polyethylene glycol sorbitan monooleate.

[0123] Preferably, the polyethylene glycol castor oil surfactant is selected from polyethylene glycol 35 castor oil (CREMOPHOR EL, KOLLIPHOR EL), polyethylene glycol 40 hydrogenated castor oil (CREMOPHOR RH40; KOLLIPHOR RH 40), PEG 40 castor oil (ETOCAS 40), PEG-60 hydrogenated castor oil (CRODURET 60) and polyethylene glycol 15-hydroxystearate (KOLLIPHOR HS15), more preferably polyethylene glycol 40 hydrogenated castor oil.

[0124] In a preferred embodiment, the microemulsion according to the present invention obtainable by the above method can be obtained by the following steps:

[0125] a) preparing a lipid phase by dissolving a surfactant / co-surfactant mixture in oil, mixing 1 to 10 parts of the mixture per part of oil;

[0126] b) preparing an aqueous phase, wherein one or more surfactants and / or co-surfactants are dissolved in water;

[0127] c) titrating the lipid phase with the aqueous phase to obtain a microemulsion, taking into account the titration rate, which is preferably described by the following formula:

[0128] V tit = k × (vtot / 1000 ml);

[0129] Where V tit = titration speed, unit is mL*min -1 , k = 2mL*min -1 , Vtot = total volume of the preparation, in mL;

[0130] Among them: 0.4-1.4% (w / v) of the microemulsion is composed of the oil component of the lipid phase; 4.0%-18.67% (w / v) of the microemulsion is composed of the surfactant / co-surfactant of the lipid phase; 1.66%-4.15% (w / v) of the total surfactant / co-surfactant is the surfactant / co-surfactant of the aqueous phase.

[0131] In another embodiment, the microemulsion according to the present invention obtainable by the above method can be obtained by the following steps:

[0132] a) preparing a lipid phase, if preparing a pharmaceutical composition according to the invention, which optionally comprises a pharmaceutically active agent, and wherein a surfactant / cosurfactant mixture is dissolved in oil, 1 to 10 parts of the mixture per part of oil;

[0133] b) preparing an aqueous phase, wherein one or more surfactants and / or co-surfactants are dissolved in water;

[0134] c) titrating the lipid phase with the aqueous phase to obtain a microemulsion, wherein: 0.4-1.4% (w / v) of the microemulsion consists of the oil component of the lipid phase; 4.0%-18.67% (w / v) of the microemulsion consists of the surfactant / co-surfactant of the lipid phase, and 1.66%-4.15% (w / v) of the microemulsion consists of the surfactant / co-surfactant of the aqueous phase.

[0135] If a pharmaceutical composition according to the present invention is prepared, the pharmaceutically active agent is preferably included in an amount of 0.001 mg / mL to 50 mg / mL of the composition, more preferably 0.01 mg / L to 50 mg / mL, even more preferably 0.01 mg / mL to 30 mg / mL.

[0136] Pharmaceutically active agents included or added to the compositions so prepared include any drug suitable for treating a particular disease, including any of the drugs listed above and below.

[0137] According to these methods, the titration rate is preferably described by the formula:

[0138] V tit = k × (vtot / 1000 ml);

[0139] Where V tit = titration speed, unit is mL*min -1 , k = 2mL*min -1 , Vtot = total volume of the preparation, in mL.

[0140] The resulting microemulsions and compositions advantageously exhibit dispersed particles with fine dispersion, preferably with an average size of ≤30 nm, and preferably with a size distribution of particles of 15 nm ± 10 nm, and / or a polydispersity index (PDI) less than or equal to 0.380, more preferably in the range of 0.01 to 0.380, more preferably 0.01 to 0.20, more preferably 0.01 to 0.15, more preferably less than 0.2, even more preferably less than 0.1.

[0141] In other methods, the microemulsions and compositions according to the present invention can be obtained by a process comprising the following steps:

[0142] a) preparing a lipid phase comprising an oil component, one or more surfactants and one or more co-surfactants and, if a pharmaceutical composition according to the invention is to be prepared, optionally a pharmaceutically active agent, and

[0143] b) an aqueous phase comprising one or more surfactants and one or more co-surfactants,

[0144] wherein the weight / volume ratio between the content of surfactant and co-surfactant in the lipid phase and the content of surfactant and co-surfactant in the aqueous phase is 2 to 5, and wherein the weight / volume ratio between the content of oil component in the lipid phase and the content of surfactant and co-surfactant in the aqueous phase is 0.2 to 0.4; and

[0145] c) Combine the lipid phase with the aqueous phase.

[0146] In this way, oil-in-water microemulsions and compositions according to the invention are formed, wherein preferably the average particle size is less than 30 nm.

[0147] Step c) is preferably achieved by titrating the lipid phase with the aqueous phase, wherein the titration rate is described by the following formula:

[0148] V tit = k × (vtot / 1000 ml);

[0149] in

[0150] V titis the speed, the unit is mL*min -1 , k = 2mL*min -1 , Vtot = total volume of the preparation, in mL.

[0151] In these methods, the weight / volume ratio of the content of surfactant and co-surfactant in the lipid phase to the content of surfactant and co-surfactant in the aqueous phase is preferably 2.2 to 4.7, more preferably 2.4 to 4.5.

[0152] The microemulsion according to the present invention provided herein is used as a pharmaceutically acceptable reservoir system for formulating an ophthalmic active ingredient for the anterior segment of the eye, preferably for an ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably for the cornea. The provided microemulsion is used to formulate such an active agent into a stable form and can also be stored at room temperature.

[0153] Due to the unexpected ability to deliver ophthalmically active ingredients to the anterior segment of the eye and to maintain high concentrations of the active ingredients on the anterior segment of the eye even for a long time after application, the oil-in-water microemulsion according to the present invention is particularly effective as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the anterior segment of the eye is preferably at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably cornea, and even more preferably for the treatment of corneal neovascularization diseases (NV).

[0154] Therefore, in another aspect of the present invention, the present invention also relates to a pharmaceutical composition for treating anterior segment diseases of the eye, said pharmaceutical composition comprising at least one ophthalmically active ingredient in an oil-in-water microemulsion according to the present invention, wherein said disease is preferably selected from diseases of at least one of the following eye structures selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably diseases of the cornea, and even more preferably for treating corneal neovascularization disease (NV).

[0155] It is noteworthy that in a first embodiment of another aspect of the present invention, the present invention therefore relates to a pharmaceutical composition for treating anterior segment diseases of the eye, said pharmaceutical composition comprising at least one ophthalmically active ingredient in an oil-in-water microemulsion, said pharmaceutical composition comprising:

[0156] an oil component, wherein the oil component is present in an amount of 0.4% to 1.4% liquid weight / volume (w / v) of the microemulsion;

[0157] an aqueous component, wherein the content of the aqueous component is 55.85% w / v to 75.70% w / v of the microemulsion;

[0158] a surfactant or a mixture of a surfactant and a co-surfactant, wherein the surfactant or the mixture of a surfactant and a co-surfactant is present in an amount of 5.71% w / v to 22.82% w / v of the microemulsion;

[0159] The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0160] In a first embodiment of this other aspect, the pharmaceutical composition is used to treat anterior segment diseases of the eye, preferably to treat at least one ocular structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably to treat the cornea, and even more preferably to treat corneal neovascularization disease (NV).

[0161] Therefore, in a second embodiment of this other aspect, the present invention also relates to a pharmaceutical composition for treating anterior segment diseases of the eye, the pharmaceutical composition comprising at least one ophthalmically active ingredient in an oil-in-water microemulsion with an average particle size of less than 30 nm, the pharmaceutical composition comprising:

[0162] a lipid phase comprising an oil component, one or more surfactants and one or more co-surfactants, and

[0163] A water phase comprising one or more surfactants and one or more co-surfactants, wherein:

[0164] The weight / volume ratio of the content of surfactant and co-surfactant in the lipid phase to the content of surfactant and co-surfactant in the aqueous phase is 2 to 5, preferably 2.2 to 4.7, more preferably 2.4 to 4.5; and

[0165] The weight / volume ratio of the content of the oil component in the lipid phase to the content of the surfactant and the co-surfactant in the aqueous phase is 0.2 to 0.4, preferably 0.22 to 0.38, more preferably 0.24 to 0.34;

[0166] The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0167] In a second embodiment of this further aspect, the pharmaceutical composition is for treating anterior segment diseases of the eye, preferably treating at least one ocular structure selected from the group consisting of bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably treating the cornea, even more preferably treating NV.

[0168] The advantages of the pharmaceutical composition according to this aspect of the invention have already been disclosed with reference to the microemulsion according to the invention and are therefore not repeated here.

[0169] With regard to the pharmaceutical composition according to the present invention, the oil-in-water microemulsion preferably exhibits the advantages, exemplary features and preferred features of the microemulsion disclosed herein above.

[0170] In the pharmaceutical composition, the ophthalmically active ingredient is preferably selected from the group consisting of anti-angiogenic agents or multikinase inhibitors, immunosuppressive and immunomodulatory agents, antioxidants and anti-inflammatory agents.

[0171] Preferably, the anti-angiogenic agent or multikinase inhibitor is selected from the group consisting of sorafenib, sorafenib tosylate, regorafenib, regorafenib tosylate, regorafenib isethionate, regorafenib, apremilast ethionate, radotinib, spironolactone, and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof or their polymorphic crystalline forms.

[0172] Preferably, the antioxidant is selected from the group consisting of nordihydroguaiaretic acid, meso-nordihydroguaiacic acid (masoprocol), and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof, or polymorphic crystalline forms thereof.

[0173] Preferably, the anti-inflammatory agent is selected from the group consisting of: nonsteroidal anti-inflammatory drugs (NSAIDs), preferably selected from the group consisting of: diclofenac, diflunisal, etodolac, fenoprofen, flurbiprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, mefenamic acid, meloxicam, nabumetone, naproxen, oxaprozin, piroxicam, sulindac, tolmetin, COX-2 selective NSAIDs, celecoxib, rofecoxib and valdecoxib; and corticosteroid anti-inflammatory drugs, preferably selected from the group consisting of: betamethasone, prednisone, triamcinolone, methylprednisolone, dexamethasone, hydrocortisone, cortisone, betamethasone (ethamethasoneb), and their pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts or their polymorphic crystalline forms.

[0174] Preferably, the immunosuppressant and immunomodulator are selected from the group consisting of: interleukin inhibitors, preferably apremilast, daclizuma, natalizumab, tocilizumab, mepolizumab, ixekizumab, secukinumab, reslizumab, and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof or polymorphic crystalline forms thereof; and TNFα inhibitors, preferably certolizumab, etanercept, adalimumab, golimumab, infliximab, and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof, or polymorphic crystalline forms thereof.

[0175] In a preferred embodiment, in the pharmaceutical composition according to the present invention, the at least one ophthalmically active ingredient is an anti-angiogenic agent, more preferably selected from the group consisting of sorafenib, sorafenib tosylate and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof, or polymorphic crystalline forms thereof.

[0176] In the pharmaceutical composition, the amount of the ophthalmically active ingredient may vary depending on the active ingredient itself and its intended indication, posology, and administration regimen.

[0177] In a preferred embodiment, the pharmaceutical composition comprises 0.001 mg / mL to 50 mg / mL, more preferably 0.01 mg / mL to 50 mg / mL, even more preferably 0.01 mg / mL to 30 mg / mL of at least one ophthalmically active ingredient.

[0178] The microemulsions and pharmaceutical compositions according to the invention can be used for external and topical applications. Preferably, the microemulsions and pharmaceutical compositions according to the invention are formulated for external applications, such as eye drops.

[0179] The microemulsions and pharmaceutical compositions according to the invention can be used to treat several anterior segment diseases.

[0180] Preferably, the anterior segment of the eye is at least one eye structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera, more preferably the cornea.

[0181] The diseases treated with the microemulsion and the pharmaceutical composition according to the present invention are selected from the group consisting of bulbar conjunctival diseases, conjunctival diseases, corneal diseases, scleral diseases, more preferably corneal diseases.

[0182] Diseases that can be treated with the microemulsion and pharmaceutical composition according to the present invention are selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma (particularly uveal melanoma and conjunctival melanoma), gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Steven Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

[0183] Ocular melanoma is the second most common melanoma after the skin. It originates from melanocytes located in the conjunctival membranes and uveal tracts of the eye. It can also arise from melanocytes located in the orbit, although this is rare. The uvea is the most common site of origin for ocular melanoma, accounting for 82.5% of all melanomas, while conjunctival melanoma is far less common. Most ocular melanomas are primary, however, metastatic melanomas from a primary skin site can also occur in the ocular region, accounting for less than 5% of all melanomas that metastasize to the eye and orbit.

[0184] Iris or anterior uveal melanoma is the least common uveal melanoma but has a more benign clinical course than posterior uveal melanoma. Most patients with uveal melanoma are between 50 and 80 years old, with the most common patients in their 70s, and the average age of diagnosis is 58 years. Iris melanoma is more common in younger patients.

[0185] Conjunctival melanoma originates from melanocytes located in the basal layer of the conjunctival epithelium. Unlike other mucous membranes, the bulbous part of the conjunctiva is directly exposed to solar radiation. Conjunctival melanoma is very rare, accounting for about 5% of all melanomas of the eye. Conjunctival melanoma occurs almost exclusively in white people, with less than 1% of patients being African-American. It does not show any gender predilection. The incidence of conjunctival melanoma increases with age; more than half of patients are over 60 years old (54%), while patients younger than 20 years old are extremely rare (1%).

[0186] Gelatinous drop-like corneal dystrophy (GDLD) is an autosomal recessive disease characterized by subepithelial and stromal deposits of gelatinous amyloid material in the cornea with an insidious onset, usually presenting in the first two decades of life. The disease was first described by Nakaizumi1 in 1914 and named gelatinous drop-like dystrophy; prior to this, it was known as primary familial amyloidosis or subepithelial amyloidosis. It is bilaterally symmetric with low penetrance, usually presenting between 8 and 18 years of age [2,3]. GDLD is a monogenic disease caused by homozygous biallelic loss-of-function mutations in the tumor-associated calcium signaling transducer 2 (TACSTD2) gene located on the short arm of chromosome 1 [4]. This gene encodes the TACSTD2 protein, which is implicated in the pathogenesis of the disease.

[0187] Secondary corneal amyloidosis-GDLD type is known to occur after chronic ocular irritation / inflammatory / infectious diseases such as trichiasis, entropion, keratoconus, etc. It is divided into three subtypes based on its clinical presentation. GDLD type secondary corneal amyloidosis is morphologically similar to GDLD lesions with milky white soft masses on the corneal surface. Correlation with clinical history is crucial in its differentiation from primary corneal amyloidosis. The deposits appear to be confined to the site of inflammation or chronic irritation.

[0188] Graves' ophthalmopathy (also known as Graves' disease) is an autoimmune disease caused by antibodies against receptors on the surface of thyroid cells and cells behind the eye. Rarely, it affects the skin, usually the skin on the front of the legs. This often leads to an overactive thyroid gland (hyperthyroidism). Up to half of people with Graves' ophthalmopathy experience eye symptoms. The most common clinical features of Graves' ophthalmopathy are upper eyelid retraction, edema, erythema of the periorbital tissue and conjunctiva, and proptosis. About 3-5% of people with Graves' ophthalmopathy have severe disease with severe pain, inflammation, and vision-threatening corneal ulcers or compressive optic neuropathy [Rebecca S. Bahn et al. N Engl J Med. 2010 February 25; 362(8):726-738].

[0189] Steven-Johnson syndrome (SJS) is a toxic epidermal necrolysis (TEN) that represents a different end of the spectrum of the same clinical entity, typically causing severe mucocutaneous reactions to medications characterized by intraepidermal cell death leading to blistering and excoriation. The severe cutaneous manifestations of this spectrum of disease often lead to neglect of ocular sequelae, which are very common and may lead to loss of visual acuity. Eyelid complications include discharge, eyelid margin ulceration and crusting, eyelid edema, eyelash adhesion, tarsal gland inflammation, blepharitis, trichiasis, and eyelid skin peeling. Conjunctival complications include conjunctivitis, conjunctival membranes, subconjunctival hemorrhage, and symblepharon. Corneal complications include superficial punctate epithelial keratitis, corneal ulcers, and punctate epithelial erosions [Abrol, et al.: Ocular manifestations of SJS / TEN, Indian Dermatology Online Journal|Volume 11|Issue 4|July-August 2020].

[0190] Mooren's ulcer is a rapidly progressive, painful ulcerative keratitis that initially affects the peripheral cornea and can spread peripherally and then centrally. Mooren's ulcer can only be diagnosed in the absence of an infectious or systemic etiology and must be differentiated from other corneal abnormalities such as Terrien's marginal degeneration. Although the etiology remains unknown, recent studies have suggested a potential immune process and a possible link to the hepatitis C virus. Response to medical and surgical interventions is often poor, with potentially devastating consequences for vision. These ulcers often respond poorly to conventional treatments because of limited understanding of the pathophysiology of the disease. Evidence for an autoimmune component supports the use of steroids and immunosuppressants.

[0191] Corneal transplant rejection: Penetrating keratoplasty is the most widely performed transplantation procedure in humans. Irreversible immune rejection of the transplanted cornea is the leading cause of mid- to late-stage failure of human allografts. Despite the use of intensive immunosuppressive therapy, this immune process causes reversible or irreversible damage to the transplanted cornea in some cases. Corneal transplant rejection involves a complex series of immune responses, including recognition of foreign histocompatibility antigens of the corneal transplant by the host immune system, leading to the initiation of an immune response cascade. The host immune system generates an efferent immune response against these foreign antigens, which ultimately leads to rejection and graft decompensation in irreversible cases. A variety of donor- and host-related risk factors contribute to the development of corneal rejection. Epithelial rejection, chronic stromal rejection, hyperacute rejection, and endothelial rejection constitute several different types of corneal transplant rejection, which may occur alone or in combination. Corneal transplant failure after transplant rejection remains a major cause of blindness, and there is an urgent need to develop new strategies to inhibit transplant rejection [Anita Panda et al. Surv Ophthalmol 52(4)July--August 2007].

[0192] In a preferred embodiment, the microemulsion and pharmaceutical composition according to the present invention are used to treat corneal neovascularization disease (NV).

[0193] Other characteristics and advantages of the invention will become more apparent from the following description of some preferred embodiments, which are described hereinafter by way of non-limiting example with reference to the following exemplary embodiments.

[0194] Experimental Section

[0195] Example 1: Exemplary Microemulsions

[0196] Two formulations were obtained using sorafenib tosylate as an active ingredient, isopropyl myristate as an oil phase, water, Tween 80 and Kolliphor RH40 as emulsifiers (surfactants), propylene glycol (co-surfactant) as a wetting agent, sodium citrate dihydrate as a buffer, and citric acid as a pH adjuster. As described in detail below, the emulsifier and wetting agent are surfactants and co-surfactants in the lipid phase and / or the aqueous phase, respectively.

[0197] Microemulsion formulation 2-F1:

[0198] Components %w / v Sorafenib Tosylate 0.300 Isopropyl myristate 1.410 Twain 80 4.150 Kolliphor RH40 11.410 Propylene glycol 7.260 Sodium citrate dihydrate 0.500 Purified water qs100mL

[0199] Formulation 2-F1 was prepared using isopropyl myristate as the oil phase component, water as the dispersant, Tween 80, propylene glycol, and Kolliphor RH40 as surfactants / co-surfactants of the lipid phase. In the lipid phase, the ratio of Tween 80, propylene glycol, and Kolliphor RH40 was 1:2:1.5. Kolliphor RH40 and propylene glycol were surfactants / co-surfactants of the water phase, wherein the ratio of Kolliphor RH40 to propylene glycol in the water phase was 3:1.

[0200] In this formulation, the surfactant / co-surfactant of the lipid phase accounts for 18.67% (w / v) of the microemulsion, and the surfactant / co-surfactant of the aqueous phase accounts for 4.15% (w / v) of the microemulsion.

[0201] Microemulsion formulation 2-F2:

[0202] Components %w / v Sorafenib Tosylate 0.300 Coconut Oil 1.410 Twain 80 4.150 Kolliphor RH40 11.410 Propylene glycol 7.260 Sodium citrate dihydrate 0.500 Purified water qs100mL

[0203] Formulation 2-F2 was prepared using coconut oil as an oil phase component, water as a dispersant, Tween 80 and Kolliphor RH40 as emulsifiers, propylene glycol as a wetting agent, sodium citrate dihydrate as a buffer, and citric acid as a pH adjuster.

[0204] Tween 80, propylene glycol and Kolliphor RH40 are surfactants / co-surfactants of the lipid phase, wherein in the lipid phase, the ratio of Tween 80, propylene glycol and Kolliphor RH40 is 1:2:1.5; Kolliphor RH40 and propylene glycol are surfactants / co-surfactants of the aqueous phase, wherein in the aqueous phase, the ratio of Kolliphor RH40 and propylene glycol is 3:1. In this preparation, the surfactant / co-surfactant of the lipid phase accounts for 4.05% (w / v) of the microemulsion, and the surfactant / co-surfactant of the aqueous phase accounts for 1.66% (w / v) of the microemulsion.

[0205] The chemical and physical characterization parameters of the preparations are shown in Tables 1 and 2.

[0206]

[0207]

[0208] The long-term stability data at 25 °C highlighted the high stability of Formulation 2-F1 under all considered chemical and physical parameters ( Figure 1 AD). The recovery of sorafenib was determined to be within the recommended specifications for all study phases ( Figure 1A). Comparison of the polydispersity index (PDI) to the mean particle distribution (size) shows that the droplet size is very small (≤ 20 nm) and the polydispersity index is very low and uniform (≤ 0.20).

[0209] Stability data of formulation 2-F2 ( Figure 2 AE) highlights all considered chemical and physical parameters ( Figure 2 The recovery of sorafenib was determined to be within the recommended specification range for all study phases under long-term conditions ( Figure 2 A). Polydispersity index ( Figure 2 D) shows very low and uniform values ​​(PDI ≤ 0.34), with droplets showing a low average particle distribution (size ≤ 22 nm).

[0210] Example 2: Bioavailability study after single-dose administration of sorafenib microemulsion (formulation 2-F1)

[0211] A bioavailability study after a single dose administration (50 μL topically applied to the right eye) was conducted in NZW rabbits, and the levels of sorafenib tosylate in plasma (PL), bulbar conjunctiva (BCJ), aqueous humor (AH), cornea (C), vitreous (V), retina (R), and sclera (SC) were assessed by LC-MS at t=5, 15, 30, 60, 90, 120 minutes after treatment.

[0212] Thirty-six NZW male rabbits weighing approximately 2 kg were used in this study. The study was performed in the testing facilities of IRIS PHARMA in accordance with GLP standards. All animals were handled in accordance with Directive 2010 / 63 / UE European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes and ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. All animals were individually housed in standard cages under the same temperature (18°C ± 3°C), relative humidity (45%-80%) and controlled enrichment conditions and exposed to a continuously ventilated room (15-20 air volumes per hour) and a 12-hour light and dark cycle. They received a standard dry pellet diet and water ad libitum. Only animals without visible signs of irritation were included in this study and were randomly divided into 6 time point groups with 6 animals in each group (Table 3).

[0213] Table 3. Study design

[0214]

[0215] Animals received a single 50 μL topical application to the right eye, were anesthetized by intramuscular injection of a mixed xylazine / ketamine mixture at the time points listed in Table 3, and then euthanized by intracardiac injection of an overdose of pentobarbital. Whole blood was sampled by intracardiac puncture and placed in EDTA anticoagulated tubes, and plasma was prepared and frozen at -23°C ± 7°C. Immediately after euthanasia, the bulbar conjunctiva (BCJ), aqueous humor (AH), cornea (C), vitreous (V), retina (R), and sclera (SC) were quickly and carefully dissected from both eyes and weighed, frozen in dry ice and then frozen at -23°C ± 7°C until analysis. According to rapid separation liquid chromatography / tandem mass spectrometry, the sorafenib content in the retina (R) and plasma (PL) of both eyes was preferentially determined, and then the aqueous humor (AH), bulbar conjunctiva (BCJ), cornea (C), vitreous (V), and sclera (SC) of both eyes were frozen.

[0216] Under the experimental conditions described, after a single instillation of 50 μL of NaMESys-SOR into the right eye of an albino rabbit, it was observed that:

[0217] In the retina of the treated eyes, the maximum level of sorafenib (170 ng / g) was observed at 5 min after treatment and decreased rapidly at 2 h after administration. For all rabbits, sorafenib was not quantified in the untreated left eye;

[0218] Sorafenib was not quantified in plasma in all rabbits from 5 to 30 minutes after dosing, and in 5 of 6 rabbits, 2 of 6 rabbits, and 1 of 6 rabbits at 1, 1.5, and 2 hours after dosing, respectively. The maximum level of sorafenib (1.7 ng / mL) was observed 2 hours after treatment;

[0219] For all rabbits, sorafenib was quantified in the bulbar conjunctiva, cornea, and sclera of the treated eyes, and not in the untreated eyes (except for 2 rabbits in the bulbar conjunctiva of 36, 3 rabbits in the cornea of ​​36, and 3 rabbits in the sclera of 36). Sorafenib quantified in the bulbar conjunctiva, cornea, and sclera of the left eye was associated with contamination by the animal (rubbing the eye with its paw). The maximum amount of sorafenib was observed in the bulbar conjunctiva and sclera 5 min after treatment and in the cornea 15 min after treatment, and slowly decreased until 2 h after dosing;

[0220] In the vitreous humor of treated eyes, the maximum level of sorafenib was observed at 5 min after treatment and decreased rapidly at 30 min after administration. Sorafenib was not quantified in untreated eyes and in the treated eyes of some rabbits (18 of 36).

[0221] In biodistribution studies, the diffusion of a drug is affected by many factors:

[0222] The molecular weight of the drug;

[0223] The drug's partition coefficient;

[0224] The size and charge of the drug reservoir system;

[0225] · Lipophilicity across membranes.

[0226] Smaller and more lipophilic drugs are cleared primarily in the posterior segment of the eye due to their ability to cross the blood-retinal barrier (BRB).

[0227] Positively charged nanoparticles appear to have more difficulty crossing the membrane barrier than neutrally and negatively charged nanoparticles.

[0228] Due to the ratio of lipid and aqueous phases, the microemulsions described in this application consist of an appropriate hydrophilic / lipophilic balance, are characterized by negatively charged particles, and show the ability to cross the blood-retinal barrier (BRB), as shown by the data ( Figure 3 A), where the maximum content of Sorafenib was observed in the retina of the treated eye 5 min after treatment, which was equal to 170 ng / g. In addition, it is clear that for these tissues, no amount of Sorafenib was detected in the untreated left eye. The highest detectable amount of Sorafenib was found in plasma 2 hours after treatment, which was equal to 2 ng / g. This excludes the possibility of systemic storage of Sorafenib ( Figure 3 B).

[0229] Surprisingly, this study showed that a large amount of sorafenib ( Figure 3 C). In particular, this study highlighted high concentrations of Sorafenib (1712 ng / g, SD = ±596) in the cornea 120 min (2 hours) after treatment, whereas in other tissues (sclera and vitreous), Sorafenib concentrations decreased 30 min after treatment.

[0230] It can be concluded that this novel drug reservoir system stabilizes sorafenib in liquid formulations and has higher bioavailability to the ocular surface, as if promoting a reserve effect; the sorafenib-loaded reservoir system is proven to be a tool to improve the medical treatment of corneal neovascularization diseases.

Claims

1. An oil-in-water microemulsion used as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, the oil-in-water microemulsion comprising: an oil component, wherein the content of the oil component is 0.4% w / v to 1.4% w / v of the microemulsion; an aqueous component, wherein the content of the aqueous component is 55.85% w / v to 75.70% w / v of the microemulsion; a surfactant or a mixture of a surfactant and a co-surfactant, wherein the surfactant or the mixture of a surfactant and a co-surfactant is present in an amount of 5.71% w / v to 22.82% w / v of the microemulsion; The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

2. An oil-in-water microemulsion used as an anterior segment ocular drug reservoir system in the treatment of anterior segment diseases, wherein the average particle size is less than 30 nm, the oil-in-water microemulsion comprising: a lipid phase comprising an oil component, one or more surfactants and one or more co-surfactants, and A water phase comprising one or more surfactants and one or more co-surfactants, wherein: The weight / volume ratio of the content of surfactant and co-surfactant in the lipid phase to the content of surfactant and co-surfactant in the aqueous phase is 2 to 5; and The weight / volume ratio of the content of the oil component in the lipid phase to the content of the surfactant and the co-surfactant in the water phase is 0.2 to 0.4; The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

3. The oil-in-water microemulsion used according to claim 1 or 2, wherein the size distribution of the particles in the microemulsion is 15 nm ± 10 nm.

4. The oil-in-water microemulsion for use according to any one of claims 1 to 3, wherein the polydispersity index (PDI) of the microemulsion is from 0.02 to 0.

380.

5. The oil-in-water microemulsion for use according to any one of claims 1 to 4, wherein the surfactant and the co-surfactant have a hydrophobic-lipophilic balance (HLB) of 8 to 16.

6. The oil-in-water microemulsion for use according to any one of claims 1 to 5, wherein the oil component is selected from the group consisting of natural oils, synthetic oils or mixtures thereof.

7. The oil-in-water microemulsion for use according to claim 6, wherein the oil is a vegetable oil or a medium-chain fatty acid ester or a long-chain fatty acid ester.

8. A pharmaceutical composition for treating anterior segment diseases of the eye, comprising at least one ophthalmically active ingredient in an oil-in-water microemulsion according to any one of claims 1 to 7, The disease is selected from the group consisting of corneal neovascularization disease (NV), ocular melanoma, gelatinous drop corneal dystrophy (GDLD), secondary corneal amyloidosis-GDLD type, Graves' ophthalmopathy, Stevens-Johnson syndrome (SJS), Mooren's ulcer and corneal transplant rejection.

9. The pharmaceutical composition for use according to claim 8, wherein the ophthalmically active ingredient is selected from the group consisting of anti-angiogenic agents or multikinase inhibitors, immunosuppressants and immunomodulators, antioxidants and anti-inflammatory agents.

10. The pharmaceutical composition for use according to claim 9, wherein the anti-angiogenic agent or multikinase inhibitor is selected from the group consisting of sorafenib, sorafenib tosylate, regorafenib, regorafenib tosylate, regorafenib isethionate, regorafenib, radotinib, pemitinib ethionate, and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof, or polymorphic crystalline forms thereof.

11. The pharmaceutical composition for use according to claim 9 or 10, wherein the immunosuppressive agent and immunomodulatory agent are selected from the group consisting of interleukin inhibitors and TNFα inhibitors.

12. A pharmaceutical composition for use according to any one of claims 9 to 11, wherein the antioxidant is selected from the group consisting of nordihydroguaiaretic acid, meso-nordihydroguaiaretic acid (masorol), and pharmaceutically acceptable derivatives, hydrates, solvates, metabolites and salts thereof, or polymorphic crystalline forms thereof.

13. A pharmaceutical composition for use according to any one of claims 9 to 12, wherein the anti-inflammatory agent is selected from the group consisting of non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroid anti-inflammatory drugs.

14. A pharmaceutical composition for use according to any one of claims 8 to 13, wherein the pharmaceutical composition comprises 0.001 mg / mL to 50 mg / mL of the ophthalmically active ingredient.

15. The oil-in-water microemulsion for use according to any one of claims 1 to 7 or the pharmaceutical composition for use according to any one of claims 8 to 14, wherein the anterior segment of the eye comprises at least one eye structure selected from the group consisting of: bulbar conjunctiva, conjunctiva, cornea and sclera.

16. The oil-in-water microemulsion for use according to any one of claims 1 to 7 or the pharmaceutical composition for use according to any one of claims 8 to 14, wherein the anterior segment of the eye is the cornea and the disease is corneal neovascularization disease (NV).

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