Ocular compositions containing muscarinic receptor modulators and novel methods of ocular administration for treating ocular diseases

Abstract

The present invention provides an ocular drug delivery method comprising the method step of topically administering to the skin of the eyelids of a subject a therapeutically effective amount of a pharmaceutical composition, wherein the pharmaceutical composition comprises: (a) a therapeutically active agent comprising a muscarinic acetylcholine receptor (mAChRs) modulator; and (b) a pharmaceutically acceptable carrier.

Description

[0001] Related patent applications for cross-reference This application claims priority to U.S. Application No. 63 / 695198, filed September 16, 2024, and U.S. Application No. 63 / 799249, filed May 2, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of ophthalmic composition technology, and more particularly to an ophthalmic composition containing a muscarinic receptor modulator and a novel method for eyelid administration in the treatment of eye diseases. Background Technology

[0003] Eye diseases affecting eye health and function encompass a range of conditions, from age-related macular degeneration, diabetic retinopathy, and retinal vein occlusion to refractive errors such as myopia and hyperopia. Other conditions include astigmatism and chronic illnesses like dry eye syndrome, characterized by insufficient lubrication and discomfort; diseases particularly related to the posterior segment of the eye remain largely untreated.

[0004] Muscarinic acetylcholine receptors (mAChRs) are expressed in both the anterior and posterior segments of the eye (especially the retina and sclera) and play a crucial role in various physiological functions. (Caulfield, MP, & Birdsall, NJ (1998). International Union of Pharmacology. XVII. Classification of muscarinic acetylcholine receptors.) Pharmacological reviews , 50 (2), 279-290. Dysregulation or hyperactivity of ocular muscarinic receptors can lead to various eye diseases, such as glaucoma, myopia, and adaptive dysfunction. Muscarinic receptor modulators (such as agonists and antagonists) play an important role in the treatment of various eye diseases, with each drug having a different mechanism of action.

[0005] For example, atropine is a major ophthalmic drug used to prevent the progression of myopia. (A. Chierigo et al.,) Pharmaceutics , 2022, 14 (5), 900. WY Wang et al., Biomedicine&Pharmacotherapy(2021) 133, 111092. Pilocarpine, as a muscarinic receptor agonist, can reduce intraocular pressure in glaucoma patients through its interaction with muscarinic receptors. Mitchelson, F. Muscarinic receptor agonists and antagonists: effects on ocular function. Muscarinic Receptors , 2012, 263-298. Scopolamine possesses properties as a muscarinic antagonist and can effectively promote the dryness effect in certain eye diseases. Yu, P. et al., (2021). Huperzine A lowers intraocular pressure via the M3 mAChR and provides retinalneuroprotection via the M1 mAChR: A promising agent for the treatment of glaucoma. Annals of Translational Medicine , 9 (4), 332. Annals of Translational Medicine , 2021, 9 (4); Rahman, MM et al., (2021). Experimental models, induction protocols, and measured parameters in dry eye disease: focusing on practical implications for experimental research. International Journal of Molecular Sciences , 2021, 22 (22), 12102. The therapeutic applications of muscarinic receptor agonists and antagonists highlight their crucial role in treating ocular diseases. However, their clinical application requires careful consideration of potential side effects and routes of administration. Developing more selective ligands targeting specific receptor subtypes holds promise for more precise treatment while reducing adverse reactions.

[0006] Myopia, characterized by axial elongation of the eyeball, increases its anteroposterior diameter, leading to retinal displacement and focal shift. It is a common condition affecting a large segment of the population, and traditional treatments include corrective lenses and medication. Muscarinic acetylcholine receptor modulators (such as atropine and pirenzepine) have been extensively studied in animal experiments and human clinical trials. The exact mechanism by which atropine slows eyeball growth is not yet clear. However, in a study involving chick scleral tissue, atropine inhibited the synthesis of glycosaminoglycans in the extracellular matrix of scleral cells. Muscarinic receptors have also been found in retinal pigment epithelial cells, and the retina is involved in transmitting signals in a cascade to target tissues—namely the choroid and / or sclera. Atropine or pirenzepine needs to reach the posterior portion of the eyeball at optimal concentrations to produce a therapeutic effect. (Upadhyay, A. et al.) Eye&contact lens , 46 (3), 129–135. Atropine is a non-selective muscarinic antagonist with equal affinity for all five acetylcholine receptor subtypes in the retina. While this makes atropine effective even at diluted concentrations, its non-selectivity results in widespread side effects, adversely affecting many parts of the eye. There are also concerns about long-term use of atropine potentially causing systemic side effects, as several anticholinergic drugs and other medications with anticholinergic properties can produce central nervous system side effects, adversely affecting cognitive function. (Fox, C. et al.) Age and ageing , 43 (5), 604–615. Pirenzepine eye drops were developed in an attempt to slow the progression of myopia as an alternative to nighttime eye drops. Pirenzepine is a more selective muscarinic receptor 1 (MR1) antagonist that, compared to M2 and M3 antagonists, reduced axial elongation in a chick model of myopia, while M2 and M3 antagonists did not prevent axial elongation. Leech, EM et al., Ophthalmic and Physiological Optics , 1995, 15 (5), 351-356. This effect of pirenzepine on myopia was further verified in tree shrews and rhesus monkeys. Cottriall, CL et al., Investigative Ophthalmology& Visual Science , 1996, 37 (7), 1368-1379; Tigges, M. et al., Optometry Vission Science.1999 Jun;76(6):397-407. Pirenzepine, as a selective M1 antagonist, has been shown to prevent myopia through the same mechanism as atropine, but without the side effects of pupil dilation and decreased accommodation in outdoor light, which are mainly mediated by M3 receptors.

[0007] A 2003 study showed that pirenzepine was well tolerated in children. (Bartlett, JD, Niemann, K., Houde, B., Allred, T., Edmondson, MJ, & Crockett, RS (2003). A tolerability study of pirenzepine ophthalmic gel in myopic children) . Journal of ocular pharmacology and therapeutics , 19(3), 271-279. In the same year, a study on the tolerance of myopic children to pirenzepine ophthalmic gel was conducted. A report in 2008 indicated that pirenzepine could effectively slow the progression of refractive errors, but its effect on axial length was not statistically significant. Siatkowski RM et al., Journal of American Association for Pediatric Ophthalmology and Strabismus ,2008, 12 (4), 332-339. For decades, eye drops have been one of the most widely used pharmaceutical preparations for treating eye diseases. (Baranowski, P. et al., Ophthalmic drug dosage forms: characterisation and research methods.) The Scientific World Journal. 2014 Mar 18:2014:861904. Currently, eye drops account for approximately 90% of ophthalmic medications, mainly due to their convenience and good patient compliance. However, the use of eye drops also has some drawbacks. The conjunctival sac has a limited volume, and the amount of eye drops used cannot exceed its capacity. Most eye drops have low bioavailability, poor targeted efficacy, and are almost impossible to administer during sleep. Anatomical and physiological limitations such as tear turnover, nasolacrimal duct drainage, reflexive blinking, and static and dynamic ocular barriers hinder the bioavailability and controlled administration of eye drops. Ripal Gaudana, AAPS J 2010 Sep;12(3):348-6. To overcome all the aforementioned drawbacks, an improved method is desired to deliver ophthalmic drugs with high targeting capabilities while simultaneously improving drug absorption by ocular tissues. In particular, a novel and effective method (such as optimal administration and topical application) is desired for ophthalmic drugs used to prevent and / or treat eye diseases (e.g., muscarinic acetylcholine receptor modulators), offering improvements in efficacy, safety, and patient compliance compared to traditional eye drop routes. Summary of the Invention

[0008] This invention provides an innovative method for using therapeutic agents, such as muscarinic acetylcholine receptor (mAChR) modulators, via the eyelids for the prevention and / or treatment of ocular diseases. Because the eyelids are close to the conjunctiva, which has 2 to 30 times greater drug permeability than the cornea, eyelid administration is a promising drug delivery route. (Davies, NM (2000). Biopharmaceutical considerations in topical ocular drug delivery.) Clinical and experimental pharmacology and physiology , 27 (7), 558-562. Because the conjunctiva is in direct contact with the eyeball and adjacent tissues, drugs reaching this tissue can be effectively distributed to the main targets of many eye diseases—the anterior and posterior ocular regions. Transdermal drug delivery via the eyelid skin may have advantages over traditional eye drops, including maintaining drug concentration at the site of action, reducing adverse reactions, improving patient convenience (especially for chronic diseases such as glaucoma), and delivering drugs even during sleep, thereby improving comfort, prolonging drug retention time, and improving overall quality of life.

[0009] Despite this potential, eyelid-based therapies are generally more effective for anterior segment eye diseases (e.g., those involving the cornea, conjunctiva, iris, or aqueous humor) due to direct drug exposure and fewer anatomical barriers. However, the eye's natural defense mechanisms—tear film thinning, tight epithelial junctions, and nasolacrimal duct drainage—significantly limit drug absorption. Therefore, only 1–7% of topical medications typically reach the aqueous humor in the anterior chamber.

[0010] The posterior segment of the eye, including the retina and vitreous humor, presents greater challenges for drug delivery via the eyelids to the fundus. Barriers such as the blood-retinal barrier and the limited permeability of the sclera and choroid hinder the effective delivery of drugs through local administration. Therefore, treatment of posterior segment diseases often requires more invasive methods, such as intravitreal injection or systemic administration, to achieve therapeutically effective drug concentrations.

[0011] This invention addresses this need by providing a novel method for delivering ocular medications posteriorly through the eyelid skin, offering promising advancements for the treatment of posterior eye diseases. Eyelid administration provides a simpler and less frightening method of use, which is particularly beneficial for the elderly and parents administering medication to children. This method overcomes the challenges of eye drop administration, such as the risk of contamination or the challenge of keeping the eyes open during use. This approach not only improves patient compliance but also reduces the physical and emotional stress associated with eye drop administration, making it a more feasible, convenient, and effective ocular treatment option.

[0012] In this invention, an innovative eyelid delivery system combines a therapeutic agent with a pharmaceutical formulation for eyelid administration. The drugs used are muscarinic acetylcholine receptor (mAChR) modulators, particularly the mAChR antagonists atropine and pirenzepine. All selected drugs can be designed and combined with emerging delivery systems and technologies, such as hydrogels, nanomicelles, liposomes, lipid-based nanoparticles, suspensions, emulsions, microneedles, vesicles, and cyclodextrin inclusion complexes. These drug-containing systems are then formulated into innovative formulations, including gels, hydrogels, ointments, creams, films, patches, gel patches, poultices, sprays, liniments, wipes, film-forming solutions, gel-forming solutions, or eye drops, all of which can be applied directly to the eyelids. Following once-daily or twice-daily administration, the duration of drug release can range from a few seconds (e.g., a single wipe) to 12 hours (e.g., a sustained-release patch). Studies have found that application through the eyelid skin not only avoids contact with the corneal surface, reducing potential eye irritation, but also significantly reduces drug exposure in anterior ocular tissues such as the aqueous humor and iridocyclitis (ICB), thereby minimizing side effects such as adaptation and photophobia. Furthermore, this invention effectively delivers the drug to the fundus (posterior segment of the eye), achieving sufficient pharmacological therapeutic levels to treat ocular diseases, with minimal systemic absorption, demonstrating advantages over traditional methods (such as eye drops and invasive injections).

[0013] In this invention, mAChR modulators include agonists, antagonists, and positive allosteric modulators (PAMs), including but not limited to: atropine or atropine sulfate, scopolamine, phenylacetamide, choline, dicyclic amine, imiclin, fexostatin fumarate, homatropine, L-scopolamine, levamlodipine, levetiracetam, methylscopolamine, nortropine, octepistiprine, octinib bromide, etc. Pilocarpine, pirenzepine or pirenzepine hydrochloride, pyridinol methanesulfonate, scopolamine trihydrate HBr, sopiromemium bromide, TBPB, tirenzepine hydrochloride, arecoline hydrobromide, norarecoline hydrochloride, tropamide and cyclopentodilate, TAK-071, MK-7622, ​​VU0119498, BAY-2413555, clozapine-d8, VU 0238429, VU0152100, VU0486846, VU0238441, VU6000918, VU10010, LY 2033298, zenomeprazole, and the crystalline hydrates, acid salts or isotopically labeled derivatives of the above drugs. Pirenzepine or pirenzepine hydrochloride, atropine or atropine sulfate, and any of their crystalline hydrate or acid salt forms are preferably used as the development drugs of the present invention.

[0014] Atropine sulfate, traditionally used for pupil dilation, has been approved in China at a low concentration of 0.01% and recently in the European Union (EU) for the control of myopia in children. A low concentration of 0.025% eye drops is approved in Japan for the control of myopia in children. Although atropine sulfate eye drops have been licensed and approved, eyelid administration has not been previously reported. Atropine activation of M3 receptors can lead to adverse side effects such as mydriasis and photophobia, primarily caused by the anterior iris and ciliary body tissues. The proposed eyelid administration method aims to minimize the concentration of atropine in the anterior segment of the eye, ensuring effective delivery to the posterior segment for optimal efficacy while minimizing adverse reactions. Pirenzepine has a long clinical history as a gastrointestinal treatment in Europe and Asia with an excellent safety profile. Although the exact anti-myopia target in the eye is still under investigation, it is recognized that pirenzepine primarily affects neural structures located in the posterior segment of the eye. Previous animal studies have utilized intravitreal or subconjunctival injections to deliver pirenzepine to these posterior segment sites. Leech EM et al.,Pirenzepine prevents form deprivation myopia in a dose dependentmanner. Ophthalmic and Physiological Optics , 15(5), 351-356; Cottrial CL etal., Prevention of form-deprivation myopia with pirenzepine: a study of drug delivery and distribution. Ophthalmic and Physiological Optics , 1999, 19 (4),327-335; Nickla DL et al., Effects of time-of-day on inhibition of lens-induced myopia by quinpirole, pirenzepine and atropine in chicks. Experimental eye research (2019) 181 , 5-14; Qian, L et al.,Pirenzepine inhibits myopia inguinea pig model by regulating the balance of MMP-2 and TIMP-2 expression andincreased tyrosine hydroxylase levels. Cell Biochemistry and Biophysics , 2015, 71 (3), 1373-1378.

[0015] In human clinical studies, pirenzepine hydrochloride was formulated with hydroxypropyl methylcellulose (HPMC) to create a high-viscosity hydrogel eye drop. However, due to the hydrophilic nature of pirenzepine hydrochloride, its corneal permeability and ocular bioavailability were not optimal. See: Cottriall, CL, & McBrien, NA (1996). The M1 muscarinicantagonist pirenzepine reduces myopia and eye enlargement in the treeshrew. Investigative ophthalmology&visual science, 37(7), 1368-1379. Tan, DT, Lam, DS, Chua, WH, Shu-Ping, DF, Crockett, RS, & Asian Pirenzepine Study Group. (2005). One-year multicenter, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepineophthalmic gel in children with myopia. SE Olitsky, Ophthalmology , 112 (1), 84-91; Olitsky, SE (2005). Safety and Efficacy of 2% Pirenzepine OphthalmicGel in Children With Myopia: A 1-Year, Multicenter, Double-Masked, Placebo-Controlled Parallel Study. Journal of Pediatric Ophthalmology and Strabismus , 42 (1), 63; Siatkowski, RM et al., (2008). Two-year multicenter, randomized, double-masked, placebo-controlled, parallel safety and efficacy study of 2%pirenzepine ophthalmic gel in children with myopia. Journal of American Association for Pediatric Ophthalmology and Strabismus , 12 (4), 332-339. The primary objective of this invention is to develop a series of local eyelid delivery systems for the prevention and treatment of myopia, which incorporate the inherent M1 / 4 selectivity of pirenzepine. Therefore, this invention achieves lower potential anterior adverse reactions (compared to atropine) by combining lower anterior exposure via the eyelid route to minimize or potentially eliminate anterior segment side effects.

[0016] To achieve more effective drug delivery to the posterior segment of the eye, this invention combines selected therapeutic agents with emerging delivery systems and technologies, such as hydrogels, nanomicelles, liposomes, lipid-based nanoparticles, suspensions, emulsions, microneedles, vesicles, and cyclodextrin complexes. These systems, combined with drugs, are ultimately formulated into innovative formulations, including ophthalmic solutions (such as sprays, aerosols, film-forming solutions, liniments, and eye drops), semi-solid formulations (such as ointments, creams, gels, gel patches, poultices, and gel-forming solutions), and solid formulations (such as films, wipes, and patches), which can be directly and conveniently applied to the eyelids. By increasing drug adhesion to the eyelids, the formulations can facilitate drug delivery to the posterior segment of the eye and prolong drug retention time.

[0017] Compared to traditional eye drops, this invention provides an optimal delivery method for muscarinic acetylcholine receptor (mAChR) modulators, which is expected to achieve breakthroughs in the prevention or treatment of myopia and other posterior ocular diseases.

[0018] On one hand, the present invention provides an ocular drug delivery method comprising applying a therapeutically effective amount of a drug composition topically to the eyelid skin of a subject, wherein the drug composition comprises: (a) a therapeutically active agent comprising a muscarinic acetylcholine receptor (mAChR) modulator; and (b) a pharmaceutically acceptable carrier.

[0019] In some embodiments, muscarinic acetylcholine receptor modulators include atropine, pirenzepine, or their crystalline hydrates or salts.

[0020] In some embodiments, the pharmaceutical composition comprises a muscarinic acetylcholine receptor modulator in a concentration range of about 0.01% (w / w) to about 10% (w / w). Preferably, the concentration range of the muscarinic acetylcholine receptor modulator is about 0.01% (w / w) to about 8% (w / w), or about 0.1% (w / w) to about 6% (w / w).

[0021] In some embodiments, the pharmaceutical composition includes a penetration enhancer to promote the penetration of the muscarinic receptor modulator.

[0022] Examples of penetration enhancers may include, but are not limited to, propylene glycol, polyethylene glycol (PEG) 200, polyethylene glycol 300, polyethylene glycol 400, hydroxypropyl-β-cyclodextrin (HP-β-CD), sulfonyl butyl ether-β-cyclodextrin (SBE-β-CD), ureoyl-β-cyclodextrin derivatives, and hydroxypropyl-γ-cyclodextrin. For example, penetration enhancers may include glycerol, polyethylene glycol, or propylene glycol at concentrations ranging from about 0.01% (w / w) to about 98% (w / w).

[0023] In some embodiments, the pharmaceutical composition comprises a surfactant.

[0024] Examples of surfactants may include, but are not limited to, polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, PEG-20 hexadecyl ether, PEG-35 castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-30 stearate, PEG-40 stearate, PEG-50 stearate, polyethylene glycol-100 stearate, Pluronic F68, Pluronics F127, povidone, tocopherol polyethylene glycol succinate, benzalkonium bromide, and benzalkonium chloride (BAK).

[0025] In some embodiments, the pharmaceutical composition comprises a gelling agent and / or a wetting agent.

[0026] Examples of gelling agents or wetting agents may include, but are not limited to, glycerin, propylene glycol, polyethylene glycol, hydroxypropyl methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, deacetylated gellan gum, polyvinyl alcohol, carbomer, sodium hyaluronate, sodium oleamide sulfonate, silicone oil, castor oil, white petrolatum, liquid petroleum, or lanolin.

[0027] In some embodiments, the concentration of the gelling agent and / or wetting agent ranges from about 0.1% (w / w) to about 20% (w / w), preferably from about 1.0% (w / w) to about 15% (w / w).

[0028] In some embodiments, the gelling agent may contain hydroxypropyl methylcellulose or sodium hyaluronate in a concentration range of about 0.01% (w / w) to about 10% (w / w).

[0029] In some embodiments, the pharmaceutical composition comprises one or more thickeners, osmotic pressure regulators, pH regulators, and preservatives.

[0030] Examples of thickeners include, but are not limited to, hydroxypropyl methylcellulose (HPMC), sodium hyaluronate, polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, microcrystalline cellulose, sodium carboxymethylcellulose (CMC-Na), anhydrous glucose, and any combination thereof.

[0031] In some embodiments, the thickener is hydroxypropyl methylcellulose (HPMC), sodium hyaluronate, sodium carboxymethyl cellulose (CMC-Na), or any combination thereof.

[0032] In some embodiments, the concentration of the thickener ranges from about 0.1% (w / w) to about 5.0% (w / w), or preferably from about 0.1% (w / w) to about 1.00% (w / w).

[0033] Examples of osmotic pressure regulators include, but are not limited to, mannitol, glucose, sorbitol, glycerol, polyethylene glycol, propylene glycol, and any combination thereof. The concentration of the osmotic pressure regulator can range from about 0.01% (w / w) to about 10.0% (w / w).

[0034] Examples of pH adjusters include, but are not limited to, tromethorphan, sodium hydroxide, hydrochloric acid, and any combination thereof. The concentration of the pH adjuster may range from about 0.01% (w / w) to about 5.0% (w / w).

[0035] In some embodiments, the pH range of the pharmaceutical composition is from about 4.0 to about 10.0.

[0036] In some embodiments, a pharmaceutically acceptable carrier may include a gel, hydrogel, ointment, cream, film, patch, gel patch, poultice, spray solution, aerosol, film-forming solution, gel-forming solution, liniment, wipe, or eye drops.

[0037] In some embodiments, this pharmaceutical composition is applied directly and primarily to the skin of the eyelids.

[0038] In some embodiments, the pharmaceutical composition is applied directly and primarily to the eyelid skin and covered by a film, patch, or gel patch. Examples of such films or patches include Tegaderm™, Mepitel® film, Opsite® Gentle and other commercially available medical films or patches.

[0039] In some embodiments, the pharmaceutical composition is one of the following formulations: gel, ointment, cream, film, patch, gel patch, poultice, spray, film-forming solution, gel-forming solution, liniment, wipe, and eye drops.

[0040] In some embodiments, the duration of drug delivery of the pharmaceutical composition ranges from about 1 second to about 12 hours.

[0041] In some embodiments, the pharmaceutical composition is applied by wiping, brushing, spraying, or using a sustained-release patch.

[0042] In some embodiments, the pharmaceutical composition is administered once, twice, or more daily.

[0043] In some embodiments, this method achieves lower anterior segment drug delivery and lower systemic drug exposure compared to methods that administer the same amount of muscarinic acetylcholine receptor modulator to the eye via eye drops.

[0044] In some embodiments, ocular drug delivery is used for the prevention or treatment of eye diseases.

[0045] In some embodiments, eye diseases include myopia or posterior segment eye diseases (e.g., age-related macular degeneration (AMD), diabetic retinopathy (DR), posterior segment eye diseases of glaucoma that cause optic nerve damage). For example, an eye disease may be myopia in a child or adolescent (e.g., a child under 18 years of age).

[0046] As used in this article, the term “or” may also imply “and”, unless such an interpretation leads to contradiction or impracticality.

[0047] As used herein, the terms “cure,” “treatment,” “medical,” or “therapy” do not necessarily mean a complete cure or elimination of a disease or condition. Any relief of the unpleasant signs or symptoms of a disease or condition to any degree is considered treatment and / or therapy.

[0048] As used herein, the terms “individual,” “patient,” or “subject” are used interchangeably. These terms do not require or are limited to situations where supervision by healthcare workers (such as physicians, registered nurses, nurse practitioners, physician assistants, service personnel, or hospice workers) is required (whether continuous or intermittent).

[0049] As used herein, a “therapeutic effective dose” refers to an adequate amount of muscarinic acetylcholine receptor (mAChR) modulator that provides a reasonable benefit / risk ratio for the ocular disease of a subject for whom treatment is appropriate. However, it should be understood that the total daily dose of muscarinic acetylcholine receptor (mAChR) modulator may be determined by the attending physician or personal trainer within the bounds of reasonable medical judgment. The specific effective dose level for any particular subject will depend on a variety of factors, including other diseases being treated and their severity; the specific ingredients used; the subject’s age, weight, general health condition, sex, and diet; the time and route of administration; the duration of administration; the drugs used in combination with or concurrently with the muscarinic acetylcholine receptor (mAChR) modulator; and factors well-known in the art of medicine or sports science. Furthermore, a “therapeutic effective dose” refers to the amount that will elicit a biological or medical response in the tissue, system, or subject sought by the investigator or clinician.

[0050] Those skilled in the art of preventing or treating eye diseases recognize that even if the condition is not completely eradicated or prevented, partial improvement or relief of its quantity or symptoms and / or effects in subjects can be considered "effective." Various indicators used to determine the effectiveness of a method are also known to those skilled in the art.

[0051] Unless otherwise defined herein, scientific and technical terms used in connection with this application should have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains. It should be understood that the invention is not limited to the specific methods, schemes, and reagents described herein, and therefore can be modified. Other terms are defined in the description of various aspects of the invention. Attached Figure Description

[0052] Figure 1 Skin penetration curves of the representative hydrogel formulation in Example 2 are described.

[0053] Figure 2 Skin penetration curves of the hydrogel formulations in Examples 3-F1 to F5 are described.

[0054] Figure 3 Skin penetration curves of the hydrogel formulations in Examples 3-F6 to F12 are described.

[0055] Figure 4 The skin penetration curves of the aqueous ophthalmic formulation in Example 1 are described.

[0056] Figure 5 The comparison of average ocular tissue and ocular fluid drug concentrations obtained by eyelid application (according to some embodiments of the invention) and ocular drop administration in Example 12 is shown.

[0057] Figure 6 The comparison of average ocular tissue and ocular fluid drug concentrations obtained by eyelid application (according to some embodiments of the invention) and ocular drop administration in Example 13 is shown.

[0058] Figure 7 Minimal anterior segment exposure and negligible systemic absorption are shown in Example 13 (according to some embodiments of the invention). Detailed Implementation

[0059] The present invention will now be described in further detail with reference to preferred embodiments and illustrated by way of examples. While the invention will be described in conjunction with preferred embodiments, it should be understood that the invention is not limited to these specific embodiments. Rather, the invention is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the invention as defined in the claims. Furthermore, numerous specific details are set forth in the detailed description of the invention to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without these specific details. In other instances, well-known methods, processes, components, and other features have not been described in detail to avoid unnecessarily obscuring various aspects of the invention.

[0060] Generally, this invention provides a novel drug delivery system for muscarinic acetylcholine receptor (mAChR) modulators administered transocularly, including atropine (or atropine sulfate), pirenzepine (or pirenzepine hydrochloride), etc. This system allows for controlled and / or sustained drug release, bypassing the rapid drug clearance problem typically associated with conventional eye drop administration methods. The drug carrier can be an aqueous formulation, such as a hydrogel or polymer matrix, or a non-aqueous formulation, all designed to adhere to the eyelid skin and control drug release. Atropine sulfate or pirenzepine hydrochloride can be converted to their respective free base forms and form salts with other organic acids such as sorbic acid, maleic acid, fumaric acid, and citric acid to enhance their hydrophobicity. The concentration of atropine sulfate or pirenzepine hydrochloride in the formulation can vary between 0.001% and 10% (w / w), preferably between 0.01% and 8%.

[0061] The invention is further illustrated by specific examples to demonstrate the method. It should be noted that these examples are for illustrative purposes only and are not intended to limit its scope. Experiments will be conducted to enhance chemical stability and improve the efficacy of atropine sulfate and / or pirenzepine delivery to the posterior ocular segment. Experimental methods without specified conditions are generally prepared under standard conditions as described in the literature or as recommended by the excipient manufacturer. Unless otherwise stated, all percentages, ratios, proportions, or fractions in this invention are calculated on a weight (w / w) basis. All technical and scientific terms used herein are assumed to be understood by one of ordinary skill in the art. Furthermore, any methods and materials identical or equivalent to those described herein are also applicable to this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0062] Example 1. An aqueous formulation containing a muscarinic acetylcholine receptor modulator Pirenzepine hydrochloride has a wide solubility range in water (up to 110 mg / ml), but the solubility of its base form is limited, which restricts the development of formulations. Therefore, in order to obtain higher solubility, this invention investigated the solubility of the free base of pirenzepine in water and in various pharmaceutical excipients (such as PEG 400 and glycerin).

[0063] Method for testing the solubility of pirenzepine free base: Weigh an appropriate amount of pirenzepine free base into a capped 2 mL test tube. Then add water, PBS or PEG 400, and excipients such as glycerol to the test tube. Vortex to dissolve the bases and form a dispersed suspension. In some samples, water is added to the pirenzepine free base mixture to obtain a pharmaceutically acceptable solution at a predetermined percentage. All samples are filtered, and the filtrate is diluted with 50% methanol before determining the content of dissolved pirenzepine free base.

[0064] As shown in Table 1, the solubility of pirenzepine free base in water is relatively low compared to pure pharmaceutical excipients (PEG 400 and glycerin) or their 5% to 50% dilutions. From a dosage perspective, 50% or pure PEG 400 and pure glycerin can dissolve at least 2% of pirenzepine free base or 2.1% of pirenzepine free base hydrate, which is equivalent to 2.52% pirenzepine hydrochloride and is suitable for formulation development. Conversely, pirenzepine free base is virtually insoluble in oily excipients such as white petrolatum and lanolin, suggesting that aqueous formulations should be the preferred choice for composition formulation development.

[0065] Table 1. Solubility test of pirenzepine free alkaloid in water and pharmaceutical excipients.

[0066] To investigate the unique physicochemical properties and skin permeability of pirenzepine free base and pirenzepine hydrochloride, we prepared several aqueous formulations as listed in Table 2.

[0067] Table 2 Aqueous preparations containing pirenzepine hydrochloride or pirenzepine base

[0068] The preparation methods of the formulations shown in Table 2 are as follows: Taking Examples 1-F3 as an example: Accurately weigh the specified amount of pirenzepine hydrochloride and slowly add it to 1.5 g of purified water under continuous stirring until completely dissolved. Accurately weigh the specified amount of glycerol and add it to the above pirenzepine hydrochloride solution. Adjust the pH to approximately 5.0-5.3 using 10 M sodium hydroxide solution or 1 M hydrochloric acid solution. Mannitol may be added selectively to adjust the osmotic pressure to 200-3000 mOsmol / kg. Finally, add purified water to a final weight of 5.0 g. Taking Examples 1-F7 as an example: Accurately weigh the specified amount of pirenzepine free base and add it to 1.5 g of glycerol under continuous stirring until completely dissolved. If necessary, adjust the osmotic pressure to 200-3000 mOsmol / kg using mannitol. Add purified water to a final weight of 5.0 g. All formulations were prepared according to the compositions specified in this example, and the pH and osmotic pressure of these formulations were tested.

[0069] Example 2. An aqueous gel formulation for ophthalmology containing a muscarinic acetylcholine receptor modulator. To improve ocular bioavailability, we have developed formulations containing penetration enhancers, whose safety and efficacy in ocular products are well-established. This optimized formulation aims to improve the penetration of the active pharmaceutical ingredient (API) into the ocular barrier without causing irritation.

[0070] This formulation comprises an API, a hydrogel or ointment base, a wetting / gelling agent, a surfactant, and a penetration enhancer. mAChR modifiers such as atropine sulfate, pirenzepine hydrochloride, or their base form (or other suitable salt or hydrated form) are uniformly dispersed in the gel or white petrolatum to ensure uniform distribution, thereby improving the efficacy of the formulation and user comfort. The API concentration is precisely adjusted to ensure optimal efficacy and safety, for example, in the range of 0.01% to 10% (w / w), preferably between 0.1% and 6% (w / w).

[0071] Wetting agents or gelling agents, such as glycerin, propylene glycol, polyethylene glycol, hydroxypropyl methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, deacetylated gellan gum, polyvinyl alcohol, carbomer, sodium hyaluronate, sodium oleamide sulfonate, silicone oil, castor oil, white petrolatum, liquid paraffin, and lanolin, can be added to soften the gel texture and keep the eyelid skin moist. To promote API penetration through the ocular membrane, the inventors have introduced a series of penetration enhancers. These may include glycerin, propylene glycol, polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol, polypropylene glycol, hydroxypropyl-β-cyclodextrin, sulfobutyl ether-β-cyclodextrin, ureoyl-β-cyclodextrin derivatives, hydroxypropyl-γ-cyclodextrin, and γ-cyclodextrin, which can enhance its solubility and bioavailability. The formulation may also contain surfactants, including polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, PEG-20 cetyl ether, PEG-35 castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-30 stearate, PEG-40 stearate, PEG-50 stearate, PEG-100 stearate, Pluronic F68, Pluronic F127, povidone, tocopherol polyethylene glycol succinate, benzalkonium bromide, and benzalkonium chloride (BAK), etc.

[0072] In the formulation, the concentrations of these enhancers were optimized to promote drug penetration while ensuring ocular surface safety and comfort. The addition of various enhancers was carefully weighed to achieve a synergistic effect, enhancing overall ocular tissue permeability and thus more effectively delivering the API to the intraocular target. The final formulation underwent stability, pH, and viscosity testing to ensure its suitability for ocular administration. The optimized formulation is planned for ocular application or direct application to the ocular surface to ensure effective API delivery to the intraocular target tissue.

[0073] We prepared a series of aqueous ophthalmic gel formulations. These formulations contained different concentrations of pirenzepine hydrochloride (ranging from 0.01% to 8.0%) and HPMC (K100M or E4M) or sodium hyaluronate (0.5%–10%). A selection of samples was used for further research; their specific compositions are detailed in Table 3. Note: 2.52% pirenzepine hydrochloride is equivalent to 2.0% pirenzepine; 5.04% pirenzepine hydrochloride is equivalent to 4.0% pirenzepine; 7.56% pirenzepine hydrochloride is equivalent to 6.0% pirenzepine.

[0074] Table 3 Aqueous ophthalmic gel compositions of Examples 2-F1 to F30

[0075] All formulations were prepared according to the composition specified in this example. Taking the pirenzepine hydrochloride formulation containing HPMC (Examples 2-F1 to F21) as an example: Accurately weigh the specified amount of pirenzepine hydrochloride and slowly add it to 1.5 g of purified water under continuous stirring until completely dissolved. Accurately weigh the specified amount of HPMC K100M and dissolve it in purified water to prepare a high-concentration gel solution. Dissolve sodium acetate, benzalkonium chloride (BAK), and disodium edetate (EDTA·2Na) in purified water to prepare an inorganic salt solution. Add a certain volume of this inorganic salt solution to the pirenzepine hydrochloride solution. Adjust the pH of both the pirenzepine hydrochloride solution and the HPMC gel to approximately 5.0-5.3 using 10 M sodium hydroxide solution or 1 M hydrochloric acid solution. Subsequently, slowly add the HPMC gel to the pirenzepine hydrochloride solution under continuous stirring. Sodium chloride or mannitol may be selectively added to adjust the osmotic pressure to 200-1000 mOsmol / kg. Finally, purified water was added to bring the weight to 5.0 g. All formulations were prepared according to the composition specified in this example. The pH, osmotic pressure, and average viscosity of the formulations in Examples 2-F1 to F30 were measured. Viscosity was determined using a DHR-2 rheometer (TA Instruments) at 20°C and a shear rate of 1 s⁻¹. - The determination was carried out under the conditions of ¹.

[0076] Example 3. Aqueous gel formulation containing wetting agent Based on the gel formulation in Example 2, a wetting agent, including glycerin, propylene glycol, or polyethylene glycol (PEG), was added to the aqueous ophthalmic gel formulation to keep the applied formulation moist on the eyelid and to ensure continuous drug diffusion. A selection of samples was used for further research; the specific composition is detailed in Table 4.

[0077] Table 4. Wetting agent-containing hydrogel compositions of Examples 3-F1 to F13

[0078] All formulations were prepared according to the composition specified in this example. Taking the pirenzepine hydrochloride formulation containing HPMC (Examples 3-F1 to F13) as an example: Accurately weigh the specified amount of pirenzepine hydrochloride and slowly add it to 1.5 g of purified water under continuous stirring until completely dissolved. Accurately weigh the specified amount of HPMC K100M and dissolve it in purified water to prepare a concentrated gel. Dissolve sodium acetate, benzalkonium chloride (BAK), and disodium edetate (EDTA·2Na) in purified water to prepare an inorganic salt solution. Add a certain volume of this inorganic salt solution to the pirenzepine hydrochloride solution. Subsequently, add glycerol or PEG400 to the pirenzepine hydrochloride solution according to the specific formulation. Adjust the pH of both the pirenzepine hydrochloride solution and the HPMC gel to approximately 5.0-5.3 using 10 M sodium hydroxide solution or 1 M hydrochloric acid solution. Then, slowly add the HPMC gel to the pirenzepine hydrochloride solution under continuous stirring. Sodium chloride or mannitol may be selectively added to adjust the osmotic pressure to 200-1000 mOsmol / kg. Finally, purified water is added to bring the final weight to 5.0 g. All formulations were prepared according to the composition specified in this example. The pH, osmotic pressure, and average viscosity of the formulations in Examples 3-F1 to F13 were determined. Viscosity was measured using a DHR-2 rheometer (TA Instruments) at 20°C and a shear rate of 1 s⁻¹. - The determination was carried out under the conditions of ¹.

[0079] Example 4. Ointment-based ophthalmic formulation Ointment formulations can form a physical barrier on the skin surface, reducing moisture evaporation and isolating the eyelids from external irritants. We prepared ointment formulations containing pirenzepine free base or pirenzepine hydrochloride, an oily base, and a lubricant or wetting agent. Table 5 details some of the samples selected for further research and their composition.

[0080] Table 5 Ointment base compositions of Examples 4-F1 to F6

[0081] All formulations were prepared according to the composition specified in this example. Taking the pirenzepine hydrochloride formulation containing white petrolatum (Example 4-F1) as an example: Accurately weigh the specified amount of pirenzepine hydrochloride and slowly add it to 0.15 g of liquid paraffin under continuous stirring until completely dispersed. Accurately weigh the specified amount of molten white petrolatum and add it to the pirenzepine hydrochloride dispersion to bring the total weight to 5.0 g.

[0082] For Examples 4-F3 and 4-F6: Accurately weigh the specified amount of pirenzepine hydrochloride (or pirenzepine free base) and slowly add it to purified water with continuous stirring. Adjust the pH of the pirenzepine hydrochloride solution to approximately 5.0-5.3 using 10 M sodium hydroxide solution or 1 M hydrochloric acid solution. For pirenzepine free base, no pH adjustment is required, resulting in an alkaline solution. Subsequently, disperse the pirenzepine hydrochloride (or pirenzepine free base) solution into the measured amount of lanolin. Finally, slowly add the molten white petrolatum to the solution with continuous stirring until the total weight reaches 5.0 g.

[0083] All formulations were prepared according to the compositions specified in this example. The pH and average viscosity of the formulations from Examples 4-F1 to F6 were determined. Viscosities were measured using a DHR-2 rheometer (TA Instruments) at 20°C and a shear rate of 1 s⁻¹. - The determination was carried out under the conditions of ¹.

[0084] Example 5. Method of administering medication through the eyelid According to the present invention, it is easy to apply aqueous gel formulations or non-aqueous ointment formulations to the eyelids. In some embodiments, to apply the formulation to the upper eyelid, a specified amount can be placed on the fingertip. Using a gentle, precise motion, the formulation can be spread along the skin of the upper eyelid, starting from the inner corner of the eye and spreading evenly towards the outer corner. This ensures even distribution and contact with the ocular epidermis. Similarly, for the lower eyelid, the application method is the opposite of that for the upper eyelid. The fingertip with the formulation can be slid along the edge of the lower eyelid, but in the opposite direction—from the outer corner to the inner corner. This method can be repeated for both eyelids to ensure complete coverage and absorption.

[0085] Accurate dosage of the formulation is crucial because it depends on the specific surface area of ​​the eyelid and the required API concentration. This personalized approach ensures that the application is both effective and comfortable for the user, maximizing drug bioavailability while minimizing waste.

[0086] Applying aqueous gel formulations or non-aqueous ointment formulations to the eyelids can be covered with films, patches, or gel patches to provide enhanced drug retention, dehydration prevention, and / or controlled delivery of active pharmaceutical formulations.

[0087] The membrane or patch may include Tegaderm™ membranes, Mepitel® membranes, Opsite® soft membranes, and other commercially available medical membranes or patches. Membranes or patches are chosen for their flexibility and moisture permeability, allowing them to comfortably conform to the skin while maintaining proper barrier function.

[0088] Similarly, drug delivery systems such as films, poultices, patches, and gel patches can be applied directly to the eyelids. After once or twice daily administration, the duration of drug release can range from a few seconds (e.g., a single wipe) to 12 hours (e.g., a sustained-release patch). This method of eyelid application is simple and precise to design, allowing for consistent and reproducible results across different patient populations. It can leverage the unique properties of gel or ointment formulations to provide controlled and sustained drug release, directly targeting the tissues behind the eye.

[0089] Example 6. Skin penetration assay of API in hydrogel ophthalmic formulations The in vivo ocular pharmacokinetic results from Examples 12 and 13 show that the eye drops containing 2% pirenzepine and HPMC K100M (a formulation from patent WO / 02096418A1, studied in clinical trials for topical ocular use) exhibited effective drug distribution in the retina / choroid. However, upon application to the eyelids, both this and similar formulations containing 6% pirenzepine (Examples 2-F2 and F10) significantly exceeded or approached the high drug concentrations in the retina / choroid achieved through ocular administration. In other words, Examples 2-F2 and F10 serve as reliable control samples for formulation development for eyelid applications. Corresponding to the in vivo eyelid model, this example establishes a classic in vitro permeation test (IVPT) method for evaluating drug percutaneous penetration, largely simulating the process of drug entry into the eyelid.

[0090] This embodiment details an IVPT method for evaluating the skin permeability of exemplary formulations containing mAChR modifiers (including atropine sulfate, pirenzepine hydrochloride, and their crystalline hydrates and salt forms) applied through the eyelids.

[0091] In vitro transdermal assays were performed using a Franz diffusion cell to measure the amount of active ingredient permeated through the skin. Small pieces of excised Bama pig skin (average thickness 1 mm) were placed in the diffusion cell (volume: 18 ml) to ensure the integrity and viability of the skin as a barrier. The sample chamber of the diffusion cell was loaded with a predetermined amount of formulation sample, ensuring uniform distribution. The recipient chamber was filled with isotonic phosphate-buffered saline (PBS) and maintained at 32°C ± 1°C with a stirring speed of 600 rpm. Periodically, 1 ml aliquots were collected from the recipient chamber, and an equal volume of fresh buffer was added to maintain the diffusion conditions. The collected samples were analyzed using high-performance liquid chromatography (HPLC) to calculate the amount of drug permeated through the skin.

[0092] Plot the cumulative drug penetration over time and calculate key pharmacokinetic parameters, such as the apparent permeability coefficient (P0.05). app(cm / s) and the cumulative amount of drug permeation through the skin. These parameters provide a deeper understanding and basis for formulation of drug delivery efficiency and potential therapeutic effects.

[0093] To investigate the in vitro and in vivo correlations of the aqueous gel formulation, referring to the ocular pharmacokinetic study in Example 12, this example examined the skin penetration of the aqueous gel formulation from Example 2 using the IVPT method. Franz pooling permeation tests were performed using Example 2-F2 and F10 as representative samples, and the results are shown in Table 6. Figure 1 As shown. The results indicate that the gel formulation of Example 2-F2 exhibited less permeability compared to Examples 2-F2 and 2-F10, which were applied to the skin surface and covered with a Tegaderm film. This film reduces moisture evaporation from the applied sample, preventing it from drying out. Examples 2-F2 and F10 showed an increasing dose-response relationship in skin penetration, essentially consistent with the ocular distribution of pirenzepine applied to the eyelids. Therefore, these IVPT results can serve as the gold standard for rapid screening of formulations developed in this invention. More directly, formulations with cumulative drug levels significantly greater than or close to those of Example 2-F2 covered with the film stand out and proceed to the next stage of research.

[0094] Table 6. Skin penetration study of the hydrogel formulation in Example 2

[0095] Example 7. Skin penetration of active pharmaceutical ingredients in a gel formulation containing a wetting agent It is well known that gels, when applied to the skin immediately within one or several hours, dry out, thus hindering the penetration of drugs from the gel carrier into the skin. To address this issue, Example 3 provides an aqueous gel formulation incorporating a wetting agent to enhance the moisturizing properties of some of the aqueous gel formulations described in Example 2. Several aqueous gel formulations containing HPMC K100M as a gelling agent and PEG 400 as a wetting agent were prepared in this example, and their IVPT studies were then conducted using the method described in Example 6.

[0096] The results of the osmotic curve investigation of pirenzepine in Examples 3-F1 to F3 are shown in Table 7 and Figure 2As shown. The wetting agent-free formulations shown in Example 6 (including Examples 2-F2 and F10) were used as control samples. The permeation curves show that, despite comparable viscosities, Examples 3-F1 and F2 had significantly higher transdermal drug delivery and apparent permeability coefficients than the control formulations. The formulations of Examples 3-F1 and F2, with lower active pharmaceutical ingredient content, even exceeded the control Example 2-F10, achieving three times the transdermal drug delivery. In contrast, the results also showed that Example 3-F3, even with lower viscosity, still exhibited slightly higher drug permeability than the wetting agent-free Example 2-F2. This significant difference highlights the superior skin penetration performance of PEG 400 in aqueous gel formulations compared to HPMC K100M alone.

[0097] Table 7. Skin penetration studies of hydrogel formulations in Examples 3-F1 to F5

[0098] Interestingly, other aqueous gel formulations using hydroxyethyl cellulose or deacetylated gellan gum as gelling agents and PEG 400 as a wetting agent, namely Examples 3-F4 and F5, exhibited only very low pirenzepine skin penetration. This suggests that the combination of ophthalmic hydrogel formulations with PEG400 as a wetting agent and HPMC K100M is more effective than gelling agents such as hydroxyethyl cellulose or deacetylated gellan gum. Furthermore, after application to the skin, PEG 400 helps maintain the moisture and softness of gel formulations containing HPMC K100M.

[0099] The findings of Example 6 and this example confirm that, compared to the control formulation without PEG 400 and administered via the upper eyelid (Example 13), the ophthalmic hydrogel formulation containing HPMC K100M and PEG 400 exhibits superior skin penetration for pirenzepine hydrochloride. Furthermore, regardless of viscosity, from as low as 20,000 mPa·s to as high as 60,000 mPa·s, the combination of HPMC K100M and PEG 400 provides sufficient drug penetration to achieve efficacy. This finding highlights the innovative value of this invention in optimizing ophthalmic gel formulations for eyelid application.

[0100] Example 8. Skin penetration study of an aqueous gel formulation containing sodium hyaluronate and a wetting agent. In addition to PEG used in the composition of Example 7, glycerin, a common humectant used in the preparation of hydrogels, provides hydration to the gel product and the skin, and facilitates drug penetration through the skin. This example prepared an aqueous gel formulation containing pirenzepine hydrochloride and a gel carrier conjugated with glycerin and sodium hyaluronate or HPMC K100M.

[0101] To achieve good drug penetration through the skin and eyelids, a medium to high viscosity is required. In this example, formulations from Examples 3-F2 to F6 were selected for IVPT studies. The viscosity of formulation 3-F1 was close to that of Examples 2-F2 and F10, while the viscosity of formulations 3-F2 to F6 was adjusted to range from 3000 mPa·s to 70000 mPa·s. Table 8 and... Figure 3 Detailed ingredient characteristics and skin penetration results are provided.

[0102] Table 8. Skin penetration studies of hydrogel formulations in Examples 3-F6 to F12

[0103] The hydrogel formulations of Examples 3-F6 exhibited lower cumulative permeability of pirenzepine hydrochloride than Control Examples 2-F2 (without a wetting agent) and Example 3-F1 (containing PEG 400 as a wetting agent). In the series of formulations containing sodium hyaluronate and glycerin, the drug permeability of Example 3-F7 was significantly higher than that of Control Examples 2-F2 and F10 tested in Example 6. These results indicate that glycerin has a significant positive promoting effect on the drug permeation of sodium hyaluronate, while having the opposite effect on the drug permeation of HPMC K100M. Simultaneously, glycerin helps maintain the moisture of the skin and the sodium hyaluronate-containing gel formulations, thereby achieving sustained drug permeation.

[0104] This example demonstrates that the gel formulation in combination with sodium hyaluronate and glycerin exceeds the transdermal levels of pirenzepine in the control sample, indicating that the drug effectively promotes distribution in the posterior part of the eye after passing through the upper eyelid. Furthermore, this gel formulation enhances the moisturizing properties of both the gel itself and the skin at the application site, demonstrating significant advantages for transdermal drug delivery via the eyelid. In summary, this example provides an alternative prospective transdermal gel delivery system option for eyelid applications using sodium hyaluronate and glycerin combinations.

[0105] Example 9. Skin penetration study of APIs in aqueous ophthalmic formulations This embodiment prepared several aqueous ophthalmic formulations containing pirenzepine hydrochloride and pirenzepine free base, comparing formulations with or without wetting agents or penetration enhancers, and then evaluating their skin permeability using the IVPT method, as shown in Example 6.

[0106] This example evaluated the Franz permeation curves of aqueous formulations Examples 1-F1 to F9, and the results are shown in Table 9 and... Figure 4 As shown. Compared to pirenzepine hydrochloride aqueous solution (Example 1-F1), Example 1-F5 containing pirenzepine free base showed significantly greater permeation drug volume and higher P. app (1.288×10) -7Further analysis showed that, although P in Examples 1-F6 and F7 was [missing information - likely a value] cm / s. app The parameters were higher, but the actual penetration volume of Examples 1-F2 and F3 was greater. When compared with the control and results in Example 6, Examples 1-F7 achieved drug penetration effects comparable to the control group with significantly lower active ingredient content, demonstrating that aqueous formulations containing pirenzepine can achieve eyelid penetration effects similar to those of Control Examples 2-F2.

[0107] Table 9. Skin penetration study of aqueous ophthalmic formulation in Example 1

[0108] It is noteworthy that Examples 1-F4 showed greater drug penetration through the skin compared to Examples 1-F8, even though both were prepared in a 15% glycerol solution. This suggests that glycerol facilitates the permeation of pirenzepine hydrochloride through the skin but is detrimental to the permeation of the free pirenzepine base. On the other hand, Examples 1-F9, containing 15% PEG400, exhibited increased permeability of the free pirenzepine base through the skin compared to Examples 1-F8 and Control Examples 2-F2 (in Example 6), indicating that PEG400 is more beneficial than glycerol for the transdermal penetration of the free pirenzepine base. The results suggest that the permeability of pirenzepine hydrochloride or its free base is weak in certain aqueous solutions, but this can be improved by adding permeation enhancers such as glycerol and PEG400, which also help maintain the continuous moisture of the sample on the skin surface.

[0109] Unlike gel formulations with high viscosity, aqueous formulations have low viscosity and flow easily on the skin, but can be prevented from drying out by adding wetting agents. Aqueous formulations can be processed into various dosage forms, such as liniments, sprays, and ointments, and filled into appropriate containers to control flowability during use. In this example, the prepared aqueous ophthalmic formulations were relatively more flowable than viscous gel formulations, and some formulations still outperformed the control group in IVPT tests, especially the pirenzepine free base formulations with significantly lower API content (Examples 1-F7).

[0110] Therefore, compared with the control group, aqueous ophthalmic preparations containing pirenzepine hydrochloride or pirenzepine base generally have satisfactory effects. The addition of wetting agents or penetration enhancers facilitates drug penetration in aqueous ophthalmic preparations. For ease of use on the eyelids, the present invention can process aqueous ophthalmic preparations into forms including liniments, sprays, foams, and wipes.

[0111] Example 10. Skin penetration study of ointment formulation composition In this embodiment, ointment formulations Examples 4-F3 and F6 were selected for IVPT testing, and the results are shown in Table 10. The ointment formulations containing pirenzepine free base or pirenzepine hydrochloride showed virtually no drug penetration through the skin, and their penetration was significantly inferior to the aqueous gel formulations (Examples 6, 7, and 8) and the aqueous formulations (Table 9 in Example 9). Therefore, the ointment formulations do not have a significant advantage over the aqueous formulations in terms of skin permeability, and further formulation optimization is necessary to improve their performance for subsequent studies.

[0112] Table 10 Results of skin penetration studies of ointment formulation compositions

[0113] Example 11. Atropine-containing formulation composition for ophthalmic application This embodiment provides a series of formulations in which the active pharmaceutical ingredient (API) is atropine and atropine sulfate or alternative forms (or other suitable salts or hydrated forms), and includes a hydrogel matrix or ointment matrix, a gelling agent, a wetting agent, a surfactant and a penetration enhancer, a pH adjuster, a metal ion chelating agent, and an osmolality adjuster. Specific formulation compositions are detailed in Table 11.

[0114] Table 11 Compositions containing atropine and atropine sulfate for ophthalmic application

[0115] Preparation methods of the formulations described in Table 11 (applicable to Examples 11-F1 to F6): Accurately weigh the specified amount of atropine and slowly add it to 1.5 g of purified water under continuous stirring until completely dissolved. Dissolve sodium acetate, benzalkonium chloride (BAK), and disodium edetate (EDTA·2Na) in purified water to prepare an inorganic salt solution. Add a certain volume of this inorganic salt solution to the atropine solution. Accurately weigh the specified amount of PEG or glycerol according to the formulation and add it to the atropine solution. Accurately weigh the specified amount of HPMC or sodium hyaluronate and dissolve it in purified water to prepare a concentrated gel stock solution. Then, add an appropriate percentage of the HPMC or sodium hyaluronate gel stock solution to the atropine solution according to the formulation. Mannitol or sodium chloride may be selectively added to adjust the osmotic pressure to 200-3000 mOsmol / kg. Finally, add purified water to bring the weight to 5.0 g.

[0116] The preparation methods for Examples 11-F7 to F12 are similar: Accurately weigh a specified amount of atropine sulfate and slowly add it to 1.5 g of purified water under continuous stirring until completely dissolved. Adjust the pH of the atropine sulfate solution to approximately 4.0-6.0 using sodium hydroxide or hydrochloric acid solution. Add a certain volume of the inorganic salt solution (containing sodium acetate, benzalkonium chloride, and disodium edetate) to the atropine solution. Accurately weigh a specified amount of PEG or glycerol according to the formulation and add it to the atropine sulfate solution, then add an appropriate percentage of HPMC or sodium hyaluronate gel stock solution to the atropine solution. Mannitol or sodium chloride may be selectively added to adjust the osmotic pressure to 200-3000 mOsmol / kg. Finally, add purified water to a final weight of 5.0 g.

[0117] Example 12. Stability Evaluation This example illustrates a concise stability assessment process for formulations used to verify the integrity and efficacy of the drug over a longer period. These formulations were stored at varying temperature and humidity levels, and their physical and chemical properties were monitored over a six-month period. The assessment included physicochemical properties such as appearance, active pharmaceutical ingredient (API) content, impurities, pH, and viscosity to confirm the formulation's stability and efficacy. Quality control specifications included appearance, content, impurities, pH, and viscosity. The comprehensive data obtained will guide the development of appropriate shelf-life and storage guidelines to ensure these formulations maintain high standards of safety, efficacy, and quality throughout their use.

[0118] Example 13. Screening study of ocular pharmacokinetics and tissue distribution. Ocular pharmacokinetic and tissue distribution studies were conducted to evaluate and compare the bioavailability of 2% pirenzepine gel applied topically to the eyelid skin versus topical eye drops. Ocular tissue distribution was assessed using New Zealand white male rabbits after a single dose. For eye drops, 40 μl of 2% pirenzepine gel was instilled into the lower conjunctival sac of each eye using a calibrated positive displacement pipette. For eyelid application, approximately 80 μl of 2% pirenzepine gel was applied to the eyelid skin. Hair on the upper eyelid was trimmed one day prior to administration, and care was taken to ensure the gel was evenly applied to the eyelid skin surface during administration.

[0119] Before euthanizing the animals, all abnormalities should be observed and recorded, and their weight changes should be measured and recorded. Samples of aqueous humor, iris-ciliary body, retina, choroid, and sclera should be collected approximately 1, 2, and 4 hours after administration, and the pirenzepine content in ocular tissues and fluids should be analyzed by liquid chromatography-tandem mass spectrometry (LC-MS / MS).

[0120] The concentrations of pirenzepine in the aqueous humor, iris-ciliary body, sclera, and retina / choroid at 1, 2, and 4 hours after a single eye drop and eyelid administration, as well as the total area under the curve (AUC), are shown in Table 12. Comparative Data Figure 5 The figure shows a comparison of the average concentration of ocular tissue and body fluids measured by the eyelid (dashed line) and the eye drops (solid line).

[0121] The results showed that this transdermal administration method resulted in lower drug concentrations in posterior tissues (such as the retina, choroid, and sclera) compared to traditional eye drop administration. Furthermore, drug concentrations in the aqueous humor and iridocillary body were also significantly reduced with eyelid-dermal administration. These results suggest that eyelid-dermal administration of pirenzepine may bypass anterior tissues, providing a more direct and effective route for the drug to reach the posterior segment of the eye. This finding was unexpected because muscarinic acetylcholine receptor antagonists (such as atropine and tropicamide) typically cause ocular side effects such as mydriasis and cycloplegia by inhibiting M3 receptors in the iris sphincter and ciliary body. These effects are usually observed with standard eye drop administration. However, transdermal administration may effectively bypass anterior tissues, thereby reducing or even eliminating related adverse reactions.

[0122] Table 12 Mean concentrations and areas under the curve of pirenzepine in aqueous humor, iridocillary body, sclera, and retina / choroid after unilateral administration in New Zealand white rabbits.

[0123] Example 14. Confirmatory ocular pharmacokinetic and tissue distribution study To further evaluate the results of the experiment, an ocular pharmacokinetic study was conducted. Three groups were designed: (1) 2% pirenzepine-HPMC K100M gel (Example 2-F2) eye drops; (2) 2% pirenzepine-HPMC K100M gel (Example 2-F2) eyelid application; and (3) 6% pirenzepine-HPMC K100M gel (Example 2-F10) eyelid application. Each group included six New Zealand rabbits weighing between 1.5 and 2.8 kg. In group (1), 40 μl of Example 2-F2 was injected into both eyes of the rabbits, while in groups (2) and (3), 80 μl of Example 2-F2 or Example 2-F10 was applied to the upper eyelids of the rabbits, respectively, and treated with Tegaderm. TMA thin film covering was applied. Eye fluid and vitreous humor were aspirated from two rabbits in each group at 1, 2, and 4 hours post-administration, with four eyes collected at each time point. Pirenzepine concentrations in plasma, aqueous humor, iridociliary body, sclera, and retina / choroid were analyzed using LC-MS / MS. Results showed that the vitreous humor concentration was below the limit of quantitation (10 ng / ml). Table 13 lists the average concentrations of pirenzepine in the aqueous humor, sclera, and retina / choroid at different time points. Figure 6 This shows a comparison of the average drug concentration in the eye tissue and eye drops (dashed line) with that in the eye drops (solid line).

[0124] Table 13. Mean concentrations of pirenzepine in plasma, aqueous humor, iris-ciliary body, sclera, and retina / choroid at different time points after a single topical application in New Zealand white rabbits.

[0125] The results clearly demonstrate that, compared to conventional eye drops, the concentration of pirenzepine administered via the upper eyelid skin route is significantly lower in the anterior segment of the eye, validating the findings of preliminary ocular pharmacokinetic studies. For the posterior segment of the eye, concentrations at 2 and 4 hours after eyelid administration are higher than at 1 hour, reflecting its sustained-release capability. Compared to eye drops of the same dose, the eyelid route results in lower pirenzepine concentrations in the retina / choroid and sclera. The 6% pirenzepine HPMC 100M gel formulation exhibits a significant advantage in drug delivery over the 2% pirenzepine formulation, indicating that therapeutic drug concentration levels in the posterior segment of the eye can be achieved via the upper eyelid skin route. This finding represents an unexpected breakthrough in ocular drug delivery systems.

[0126] Total exposure to pirenzepine in ocular tissues, fluids, and plasma is shown in Table 14 and Figure 7 Specifically, Figure 7 The results showed that pirenzepine had very little exposure in the anterior segment of the eye, and systemic absorption was negligible.

[0127] Table 14. Area under the curve (AUC) of pirenzepine in aqueous humor, iridocillary body, retina / choroid, sclera, and plasma after administration of 2% PIR eyelids and 2% PIR eye drops.

[0128] Compared to topical eye drops, administration via the eyelid resulted in significantly lower drug exposure in the anterior segment and relatively lower plasma concentrations, suggesting lower systemic risk. These results indicate that using the eyelid skin route of administration avoids anterior segment side effects associated with eye drops (such as pupillary dilation and impaired accommodation) and reduces systemic safety issues due to systemic absorption.

[0129] In summary, eyelid delivery, as a novel ocular drug delivery route, shows potential for effectively delivering drugs to the posterior segment of the eye, achieving therapeutic concentrations while minimizing exposure to anterior segment tissues and systemic circulation. This targeted delivery method is expected to reduce side effects such as pupillary dilation and photophobia.

[0130] Studies have shown that, compared to other skin sites, eyelid skin has a thinner stratum corneum and lower resistance, thus facilitating greater drug penetration. This characteristic makes the eyelid a highly promising site for ophthalmic drug administration, potentially improving drug delivery efficiency within ocular tissues. Furthermore, local drug administration via the eyelid skin may bypass some common anatomical and physiological barriers that hinder drug penetration into the posterior segment of the eye. This approach could provide a non-invasive alternative to traditional drug delivery methods, thereby improving patient compliance and reducing systemic side effects.

[0131] According to the present invention, by utilizing the skin of the upper eyelid as a route of drug administration, a highly promising strategy for targeted ocular drug delivery is provided, which is expected to improve therapeutic efficacy while reducing the occurrence of adverse reactions.

[0132] Although specific embodiments and examples of the invention have been described herein, those skilled in the art will understand that any modifications and alterations can be made without departing from the spirit of the invention. The foregoing examples and descriptions are not intended to limit the scope of the invention. Any combination of embodiments of the invention, as well as any obvious extensions or similar schemes, are within the scope of protection of the invention. Furthermore, the invention is intended to cover any arrangement designed to achieve the same purpose, and all such variations and modifications fall within the scope of the appended claims.

[0133] All features disclosed in this specification (including any appended claims, abstracts, and drawings) may be replaced by alternative features having the same, equivalent, or similar function, unless otherwise expressly stated. Therefore, unless otherwise expressly stated, each disclosed feature is an example of a series of equivalent or similar features.

Claims

1. A method for ocular drug delivery, comprising the step of topically applying a therapeutically effective amount of a pharmaceutical composition to the eyelid skin of a subject, wherein the pharmaceutical composition comprises: (a) A therapeutically active agent containing a muscarinic acetylcholine receptor (mAChR) modulator; (a) and (b) a pharmaceutically acceptable carrier.

2. The method according to claim 1, wherein the muscarinic acetylcholine receptor modulator comprises atropine, pirenzepine, or their crystalline hydrates or salts.

3. The method according to claim 1 or 2, wherein the muscarinic acetylcholine receptor modulator comprises pirenzepine or pirenzepine hydrochloride, or atropine or atropine sulfate.

4. The method according to any one of claims 1 to 3, wherein the pharmaceutical composition comprises a muscarinic acetylcholine receptor modulator in a concentration ranging from about 0.01% (w / w) to about 10% (w / w).

5. The method of claim 4, wherein the pharmaceutical composition comprises a muscarinic acetylcholine receptor modulator in a concentration range of about 0.01% (w / w) to about 8% (w / w) or about 0.01% (w / w) to about 6% (w / w).

6. The method according to any one of claims 1 to 5, wherein the pharmaceutical composition further comprises a penetration enhancer to promote the penetration of the muscarinic receptor modulator through the eyelid skin.

7. The method of claim 6, wherein the penetration enhancer comprises glycerol, propylene glycol, polyethylene glycol (PEG) 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol, polypropylene glycol, hydroxypropyl-β-cyclodextrin (HP-β-CD), sulfobutyl ether-β-cyclodextrin (SBE-β-CD), ureoyl-β-cyclodextrin derivative, hydroxypropyl-γ-cyclodextrin (HP-γ-CD), or γ-cyclodextrin (γ-CD).

8. The method of claim 7, wherein the penetration enhancer comprises glycerol, polyethylene glycol or propylene glycol in a concentration range of about 0.01% (w / w) to about 98% (w / w).

9. The method according to any one of claims 1 to 8, wherein the pharmaceutical composition further comprises a surfactant.

10. The method of claim 9, wherein the surfactant comprises polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, PEG-20 hexadecyl ether, PEG-35 castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-30 stearate, PEG-40 stearate, PEG-50 stearate, PEG-100 stearate, Pluronic F68, Pluronic F127, povidone, tocopherol polyethylene glycol succinate, benzalkonium bromide, or benzalkonium chloride (BAK).

11. The method according to any one of claims 1 to 10, wherein the pharmaceutical composition further comprises a gelling agent and / or a wetting agent.

12. The method of claim 11, wherein the gelling agent and / or wetting agent comprises glycerin, propylene glycol, polyethylene glycol, hydroxypropyl methylcellulose, sodium carboxymethyl cellulose, hydroxyethyl cellulose, deacetylated gellan gum, polyvinyl alcohol, carbomer, sodium hyaluronate, sodium oleate amide sulfonate, silicone oil, castor oil, white petrolatum, liquid paraffin, or lanolin.

13. The method of claim 12, wherein the gelling agent comprises hydroxypropyl methylcellulose or sodium hyaluronate in a concentration range of about 0.01% (w / w) to about 10% (w / w).

14. The method according to any one of claims 1 to 13, wherein the pharmaceutical composition further comprises a thickener, an osmotic pressure regulator, a pH regulator, a buffer regulator, a preservative, a film-forming agent, a propellant, a tissue material, or a backing material.

15. The method according to any one of claims 1 to 14, wherein the pharmaceutically acceptable carrier comprises a gel, hydrogel, ointment, cream, film, patch, gel patch, spray solution, aerosol, film-forming solution, gel-forming solution, or eye drops.

16. The method according to any one of claims 1 to 15, wherein the pharmaceutical composition is applied directly and primarily to the eyelid skin.

17. The method according to any one of claims 1 to 16, wherein the pharmaceutical composition is applied directly and primarily to the eyelid skin and covered with a film, patch, or gel patch.

18. The method according to any one of claims 1 to 17, wherein the dosage form of the pharmaceutical composition is selected from: gels, hydrogels, ointments, creams, films, patches, gel patches, poultices, sprays, liniments, wipes, film-forming solutions, gel-forming solutions, and eye drops suitable for eyelid application.

19. The method according to any one of claims 1 to 18, wherein the drug delivery duration of the pharmaceutical composition ranges from about 1 second to about 12 hours.

20. The method according to any one of claims 1 to 19, wherein the pharmaceutical composition is applied by wiping, brushing, spraying or using a sustained-release patch.

21. The method according to any one of claims 1 to 20, wherein the pharmaceutical composition is administered once, twice, or more daily.

22. The method according to any one of claims 1 to 21, wherein the method has lower anterior segment drug delivery and lower systemic drug exposure compared to the method of administering the same amount of muscarinic acetylcholine receptor modulator to the eye via eye drops.

23. The method according to any one of claims 1 to 22, wherein the ocular drug delivery is used for the prevention or treatment of an eye disease.

24. The method of claim 23, wherein the eye disease is myopia.

25. The method of claim 24, wherein the eye disease is myopia in children or adolescents.

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