Hypotonic hydrogel formulations for enhanced transport of active agents at mucosal surfaces

Abstract

To provide hypotonic hydrogel formulations for enhanced transport of active agents at mucosal surfaces.SOLUTION: Hypotonic gelling vehicles are used as solubilizing agents for drugs and as a means to provide sustained drug delivery to a mucosal tissue. Solubilizing drugs at higher concentrations enhances drug penetration into the tissues of the body, while the hypotonic gelling vehicle further improves distribution of the drug over a larger surface area for increased absorption and sustained release for reduced side effects and longer duration of action. The invention can provide improved compositions for delivery of active agents with greater efficacy and safety to mucosal surfaces that act as barriers to pathogen transport into the mucosa.SELECTED DRAWING: None

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Application No. 62 / 596,578, filed December 8, 2017, and U.S. Provisional Application No. 62 / 627,559, filed February 7, 2018, which are incorporated by reference in their entireties.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with Government support under Grant No. RO1DK107806 awarded by the National Institutes of Health. The Government has certain rights in this invention.

[0003] FIELD OF THEINVENTION The present invention is generally in the field of formulations for enhanced drug delivery, particularly at mucosal surfaces. [Background technology]

[0004] 2. Background of the Invention Mucosa is the membrane that lines various cavities of the body, such as the oral cavity, digestive tract, uterus, vagina, colon, anal canal, trachea, lungs, bladder, etc. As used herein, skin may be considered a mucosal surface. The mucosa consists of the epithelium itself, and also the supporting loose connective tissue, called the lamina propria, that lies just below the epithelium. The deeper connective tissue that supports the mucosa is called the submucosa. In the GI tract, there is a thin smooth muscle layer, the muscularis mucosa, at the boundary between the mucosa and the submucosa.

[0005] Mucosal surfaces in the body are selectively permeable. Mucosal barrier damage (e.g., oral and gastrointestinal mucositis) is a common complication following cytoreductive cancer therapy and radiotherapy (Sonis et al., 2003). Cancer Supplement, 100(9):1995-2023, 2004). Some capsid viruses can spread through mucus as quickly as through water, even though they must spread "upstream" through continuously secreted mucus, thereby penetrating the epithelium. These viruses are able to penetrate the mucus meshwork (mucus membrane) and thus the mucus membrane. mesh spacing) and has a surface that does not stick to mucus (Cone RA, Adv. Drug Deliv Rev, 61(2):75-85, 2009). For example, women are disproportionately infected with HIV, due in part to the lack of female-controlled prevention methods (Ndesendo et al., AAPS PharmSciTech, 9:505-520, 2008). An easily administered, sensible, and effective method to protect women against vaginal HIV transmission could prevent millions of infections worldwide. However, the vaginal folds, or "vaginal rugae," that accommodate dilation during sexual intercourse and childbirth are typically folded by intraperitoneal pressure, making the surfaces of these folds less accessible to drugs and drug carriers (Alexander et al., 2009). (Eds. et al., Sex Transm Dis, 29:655-664, 2004). Insufficient distribution to the vaginal folds has been cited as a significant factor in the failure to protect susceptible vaginal surfaces from infection, even after simulated intercourse. Distribution across susceptible target surfaces has proven important for preventing and treating infection. Furthermore, to enhance user accessibility, drugs delivered to the vagina should be retained in the vaginal area in effective concentrations for extended periods of time.

[0006] Achieving sustained local drug concentration is difficult because vaginal epithelium is highly permeable to small molecules, as well as soluble drug dosage forms (gels, creams) can be expelled by intraperitoneal pressure and walking.Finally, drug delivery methods must be safe and non-toxic to vaginal epithelium.Improvements in the distribution, retention, and safety profile of vaginal dosage forms can lead to a substantial increase in efficacy and a decrease in side effects caused by largely ineffective systemic treatments for cervical vaginal infections and diseases (Thigpen T. Cancer J. 9:245-432, 2003; Robinson et al., Obstet Gynecol, 99:777-784, 2002).

[0007] Sustained drug delivery to mucosal surfaces of the body has the potential to improve the treatment and prevention of many diseases, including sexually transmitted diseases, inflammatory bowel disease, pulmonary inflammation, and degenerative conditions of the eye, to name just a few. Achieving sustained prophylactic or therapeutic drug concentrations using traditional soluble dosage forms remains difficult due to drug degradation, rapid shedding, and rapid systemic absorption. There is an unmet need for compositions for delivery to mucosal surfaces that provide a physical barrier against pathogen ingress. There is also an unmet need for compositions for mucosal delivery that provide retention and sustained release of prophylactic, therapeutic, or diagnostic agents at mucosal surfaces.

[0008] It is therefore an object of the present invention to provide improved compositions for delivering active agents with greater efficacy and safety to mucosal surfaces which act as a barrier to pathogen transport to the mucosa.

[0009] It is a further object of the present invention to provide improved compositions for delivery to mucosal surfaces that allow for retention and sustained release of prophylactic, therapeutic or diagnostic agents at the mucosal surface.

[0010] It is yet a further object of the present invention to provide methods of making improved compositions for delivery to mucosal surfaces. [Prior art documents] [Non-patent literature]

[0011] [Non-Patent Document 1] Sonis et al., Cancer Supplement, 100(9):1995-2023, 2004 [Non-Patent Document 2] Cone RA, Adv. Drug Deliv Rev, 61(2):75-85, 2009 [Non-Patent Document 3] Ndesendo et al., AAPS PharmSciTech, 9:505-520, 2008 [Non-Patent Document 4] Alexander et al., Sex Transm Dis, 29:655-664, 2004 [Non-Patent Document 5] Thigpen T. Cancer J. 9:245-432, 2003; Robinson et al., Obstet Gynecol, 99:777-784, 2002 Summary of the Invention [Means for solving the problem]

[0012] Summary of the Invention Hypotonic gelling vehicles are used as solubilizing agents for drugs with low water solubility. This approach contrasts with using nanoparticles or nanocrystals to improve the solubility / dissolution of hydrophobic drugs. While solubilization of the drug enhances mucosal penetration, hypotonic gelling vehicles further improve distribution and permeation. Many drugs have only minimal water solubility, limiting their delivery to mucosal surfaces.

[0013] Solubilization of drugs in thermosensitive gelling vehicles improves the distribution, retention and permeation of locally delivered drugs when administered hypotonic. Hypotonic formulations of hydrogel-forming polymers, preferably poloxamers (non-ionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene, such as poly(propylene oxide), flanked by two hydrophilic chains of polyoxyethylene, such as poly(ethylene oxide)), have been developed for enhanced delivery of therapeutic, diagnostic, prophylactic or other agents to epithelial tissues, particularly those with mucosal coverings. The polymers are administered in hypotonic solutions at concentrations below their nominal critical gelling concentration (CGC). Typically, poloxamer gels administered to the vagina or colorectum at their CGC form a gel "plug" in the lumen. In contrast, fluid from a poloxamer solution administered at a hypotonicity below its CGC is absorbed by the epithelial surface, pulling the poloxamer up against the epithelium into the mucus layer where the fluid then becomes concentrated enough to gel, thereby enhancing and facilitating delivery of the drug to the epithelial cells. As the poloxamer becomes concentrated at the tissue / mucosa interface, it mixes with the mucus and gels against the epithelial surface. Endogenous mucin glycopolymers affect the gelling properties of the hypotonic gelling agent, including the concentration of gelling agent required for gelation and the pore structure concentration of the resulting gel / mucin mixture. The hypotonic gelling vehicle coats the epithelium, including the folds, after vaginal and colorectal application.

[0014] Studies have demonstrated the advantages of these hypotonic polymer gel formulations, particularly for drug delivery across mucosal epithelia. The present invention provides, for example, the following items. (Item 1) 1. A formulation for delivery of a therapeutic agent, a prophylactic agent, a diagnostic agent, or a functional nutritional factor, said formulation comprising: Therapeutic agents, preventive agents, functional nutritional factors or diagnostic agents, A gel-forming polymer for application to mucosal tissue or skin, the gel-forming polymer being formulated such that the gel-forming polymer is at a concentration below the critical gel concentration (CGC) of the polymer under isotonic conditions and at a temperature between room temperature and body temperature (about 25 to about 37° C.); and excipients for forming a pharma- ceutically acceptable hypotonic formulation of said polymer suitable for delivery to an individual in need thereof; A formulation comprising: (Item 2) 2. The formulation according to item 1, in dry or liquid form. (Item 3) 3. The formulation according to any one of items 1 to 2, wherein the gel-forming polymer is a temperature-sensitive gel-forming polymer. (Item 4) 4. The formulation according to item 3, wherein the temperature-sensitive gel-forming polymer has a lower critical solution temperature of less than 30° C., preferably less than 21° C. (Item 5) 5. The formulation according to any one of items 1 to 4, wherein the polymer is a poloxamer. (Item 6) 6. The formulation according to any one of items 1 to 5, wherein the polymer in combination with an excipient forms a gel on a mucosal or epithelial surface selected from the group consisting of oral, pharyngeal, esophageal, pulmonary, ocular, aural, nasal, buccal, lingual, vaginal, cervical, urogenital, gastrointestinal, anorectal, and cutaneous surfaces. (Item 7) 7. The formulation of item 6, wherein the epithelial surface is on or in the eye. (Item 8) 8. The formulation according to any one of items 1 to 7, wherein the drug is water-soluble. (Item 9) 8. The formulation according to any one of items 1 to 7, wherein the drug is poorly water soluble. (Item 10) 10. The formulation according to any one of items 1 to 9, wherein the formulation releases the therapeutic, prophylactic or diagnostic agent at the epithelial surface for a period of at least 12 hours. (Item 11) 11. The formulation of claim 10, wherein the formulation releases the therapeutic, prophylactic, or diagnostic agent at the epithelial surface for a period of at least 24 hours. (Item 12) 12. The formulation according to any one of the preceding claims, wherein the gel-forming polymer is between more than 12% and less than 24% F98 in the aqueous vehicle. (Item 13) 12. The formulation according to any one of the preceding items, wherein the gel-forming polymer is between 10 and 18% F127. (Item 14) 14. The formulation according to any one of items 1 to 13, wherein the gel-forming polymer forms a uniformly thick layer upon administration onto the epithelial surface. (Item 15) 15. The formulation according to any one of items 1 to 14, for administration in the form of a dry powder, a gel, or a liquid. (Item 16) 16. The formulation according to item 15, wherein the formulation is provided in a single dosage unit or multiple dosage units for administration. (Item 17) 17. The formulation according to any one of items 1 to 16, wherein the agent is a protein or peptide, a small molecule, a sugar or polysaccharide, a lipid, a glycolipid, a glycoprotein, a nucleic acid, an oligomer or polymer thereof, or a small molecule. (Item 18) 16. The formulation according to any one of items 1 to 15, wherein the drug is selected from the group consisting of steroids, glaucoma drugs, tyrosine kinase inhibitors, immunosuppressants, antifibrotic drugs, anti-infective drugs, hormones and chemotherapeutic drugs. (Item 19) 19. A method for administering a drug to a mucosal or epithelial surface, said method comprising administering to a site in need thereof a formulation according to any one of items 1 to 18. (Item 20) 20. The method of claim 19, wherein the surface is on or in the eye. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a scheme for solubilization of a hydrophobic drug (e.g., cyclosporine A or budesonide) by the solvent evaporation method.

[0016] [Diagram 2] FIG. 2 is a scheme for solubilization of hydrophobic drugs (eg, moxifloxacin) by bead milling.

[0017] [Diagram 3] FIG. 3 is a scheme for solubilization of a hydrophobic drug (eg, cyclosporine A or brimonidine) by dialysis.

[0018] [Figure 4] FIG. 4 is a scheme for solubilization of a hydrophobic drug (eg, Brinzolamide) by the solvent evaporation method.

[0019] [Figure 5A] FIG. 5A is a graph showing the effect of various concentrations of Pluronic F127 (10%, 12%, 15%, and 18%) on the cumulative increase in tear production induced by cyclosporine in healthy rabbit eyes over a 12-hour period after a single eye drop. FIG. 5B is a graph of tear production in healthy rabbit eyes 10 hours after each of a 5-day dose of gelCsA, drug-free gel vehicle (gelCsA vehicle), Restasis, Restasis vehicle (Endura), or no treatment (non-treatment). FIGs. 5C and 5D are line graphs showing the concentration of cyclosporine in rat corneal (FIG. 5C) and conjunctival (FIG. 5D) tissues over an 8-hour period after administration of cyclosporine eye drops formulated as gelCsA (hypotonic), gelCsA (isotonic), gelCsA (conventional), or Restasis. [Figure 5B]FIG. 5A is a graph showing the effect of various concentrations of Pluronic F127 (10%, 12%, 15%, and 18%) on the cumulative increase in tear production induced by cyclosporine in healthy rabbit eyes over a 12-hour period after a single eye drop. FIG. 5B is a graph of tear production in healthy rabbit eyes 10 hours after each of a 5-day dose of gelCsA, drug-free gel vehicle (gelCsA vehicle), Restasis, Restasis vehicle (Endura), or no treatment (non-treatment). FIGs. 5C and 5D are line graphs showing the concentration of cyclosporine in rat corneal (FIG. 5C) and conjunctival (FIG. 5D) tissues over an 8-hour period after administration of cyclosporine eye drops formulated as gelCsA (hypotonic), gelCsA (isotonic), gelCsA (conventional), or Restasis. [Figure 5C] FIG. 5A is a graph showing the effect of various concentrations of Pluronic F127 (10%, 12%, 15%, and 18%) on the cumulative increase in tear production induced by cyclosporine in healthy rabbit eyes over a 12-hour period after a single eye drop. FIG. 5B is a graph of tear production in healthy rabbit eyes 10 hours after each of a 5-day dose of gelCsA, drug-free gel vehicle (gelCsA vehicle), Restasis, Restasis vehicle (Endura), or no treatment (non-treatment). FIGs. 5C and 5D are line graphs showing the concentration of cyclosporine in rat corneal (FIG. 5C) and conjunctival (FIG. 5D) tissues over an 8-hour period after administration of cyclosporine eye drops formulated as gelCsA (hypotonic), gelCsA (isotonic), gelCsA (conventional), or Restasis. [Figure 5D]FIG. 5A is a graph showing the effect of various concentrations of Pluronic F127 (10%, 12%, 15%, and 18%) on the cumulative increase in tear production induced by cyclosporine in healthy rabbit eyes over a 12-hour period after a single eye drop. FIG. 5B is a graph of tear production in healthy rabbit eyes 10 hours after each of a 5-day dose of gelCsA, drug-free gel vehicle (gelCsA vehicle), Restasis, Restasis vehicle (Endura), or no treatment (non-treatment). FIGs. 5C and 5D are line graphs showing the concentration of cyclosporine in rat corneal (FIG. 5C) and conjunctival (FIG. 5D) tissues over an 8-hour period after administration of cyclosporine eye drops formulated as gelCsA (hypotonic), gelCsA (isotonic), gelCsA (conventional), or Restasis.

[0020] [Figure 6A] Figures 6A and 6B are line graphs showing the change in intraocular pressure as a function of time (in hours) with different treatments. Figure 6A is a graph showing the change in intraocular pressure over an 8-hour period when treated with gelBRZ formulated as a conventional (18% F127) gelling agent or at a low concentration (12% F127) formulated either hypotonic or isotonic. Figure 6B is a graph showing the change in intraocular pressure over an 8-hour period when treated with a hypotonic gelBRZ formulation, the commercially available eye drop AZOPT®, or gelBRZ vehicle. [Figure 6B] Figures 6A and 6B are line graphs showing the change in intraocular pressure as a function of time (in hours) with different treatments. Figure 6A is a graph showing the change in intraocular pressure over an 8-hour period when treated with gelBRZ formulated as a conventional (18% F127) gelling agent or at a low concentration (12% F127) formulated either hypotonic or isotonic. Figure 6B is a graph showing the change in intraocular pressure over an 8-hour period when treated with a hypotonic gelBRZ formulation, the commercially available eye drop AZOPT®, or gelBRZ vehicle.

[0021] [Figure 7A] Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT. [Figure 7B] Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT. [Figure 7C]Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT. [Figure 7D] Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT. [Figure 7E]Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT. [Figure 7F] Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT. [Figure 7G]Figure 7A is a bar graph showing the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% in 10%, 12%, 15%, and 18% F127 (gelBT). Figure 7B is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, isotonic gelBT (12% F127), or conventional gelBT (18% F127) in normotensive rabbits. Figure 7C is a line graph showing the change in intraocular pressure over a 10-hour period when treated with a hypotonic gelBT formulation, a commercially available 0.15% brimonidine tartrate eye drop (ALPHAGAN®), or gelBT vehicle. Figures 7D-7F show brimonidine levels in the cornea (Figure 7D), conjunctiva (Figure 7E), and aqueous humor (Figure 7F) of rats 1 hour, 4 hours, and 8 hours after the last dose (given twice daily for 5 days). Figure 7G is a line graph showing the change in intraocular pressure when treated with mild hypotonic (gelBT 200 mOsm) or hypotonic gelBT.

[0022] [Figure 8A] Figure 8A is a bar graph showing the viscosity under low / no shear for a standard lubricating eye drop (GENTEAL®), 16% F127, and 16% F127 with 0.5% HPMC. Figure 8B shows the shear thinning properties (decrease in viscosity when placed under shear) for GENTEAL®, 16% F127, and 16% F127 with 0.5% HPMC. [Figure 8B] Figure 8A is a bar graph showing the viscosity under low / no shear for a standard lubricating eye drop (GENTEAL®), 16% F127, and 16% F127 with 0.5% HPMC. Figure 8B shows the shear thinning properties (decrease in viscosity when placed under shear) for GENTEAL®, 16% F127, and 16% F127 with 0.5% HPMC.

[0023] [Figure 9A]Figures 9A and 9B are histograms showing concentrations of sunitinib or N-desethylsunitinib in various ocular tissues and fluids of Dutch belted rabbits (Figure 13A) after 14 days of daily topical administration of sunitinib malate in a hypotonic gelling vehicle (gelSUN) and of domestic pigs after 5 days of daily topical administration of sunitinib malate in a hypotonic gelling vehicle (gelSUN). [Figure 9B] Figures 9A and 9B are histograms showing concentrations of sunitinib or N-desethylsunitinib in various ocular tissues and fluids of Dutch belted rabbits (Figure 13A) after 14 days of daily topical administration of sunitinib malate in a hypotonic gelling vehicle (gelSUN) and of domestic pigs after 5 days of daily topical administration of sunitinib malate in a hypotonic gelling vehicle (gelSUN). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Detailed Description of the Invention I. Definition As generally used herein, "pharmacologically acceptable" refers to those compounds, substances, compositions, and / or dosage forms that are suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, within the scope of sound medical judgment, commensurate with a reasonable benefit / risk ratio.

[0025] "Biocompatible" and "biologically compatible," as used herein, generally refer to a substance that, together with any metabolic or decomposition products of the substance, is generally non-toxic to, and does not cause any significant adverse effects in, the recipient. Generally speaking, a biocompatible substance is one that does not elicit a significant inflammatory, immune, or toxic response when administered to an individual.

[0026] The terms "gel" and "hydrogel", as used herein, refer to a swollen, water-containing network of water-insoluble, finely dispersed polymer chains, where the polymer molecules are in the exterior or dispersed phase and water (or an aqueous solution) forms the interior or dispersed phase. The chains may be chemically crosslinked (chemical gels) or physically crosslinked (physical gels). Chemical gels have polymer chains connected through covalent bonds, whereas physical gels have polymer chains linked by non-covalent bonds or cohesive forces (e.g., van der Waals interactions, ionic interactions, hydrogen bonds, or hydrophobic interactions).

[0027] The polymer chains are typically hydrophilic or contain hydrophilic polymer blocks. "Gel-forming polymer" is used to describe any biocompatible polymer (including homopolymers, copolymers, and combinations thereof) that can form a physical hydrogel in an aqueous medium when present at or above its critical gel concentration (CGC).

[0028] "Critical gel concentration" or "CGC" as used herein refers to the minimum concentration of a gel-forming polymer required for gel formation, e.g., at which a solution to gel (sol-gel) transition occurs. The critical gel concentration can depend on many factors, including the particular polymer composition, molecular weight, temperature, and / or the presence of other polymers or excipients.

[0029] The term "thermosensitive gel-forming polymer" refers to a gel-forming polymer that exhibits a change in one or more properties with a change in temperature. For example, some thermosensitive gel-forming polymers are water-soluble below a certain temperature, but become water-insoluble as the temperature increases. The term "lower critical solution temperature (LCST)" is the temperature below which the gel-forming polymer and the solvent are completely miscible and form a single phase. For example, the "LCST of a polymer solution" means that the polymer is uniformly dispersed in the solution at or below that temperature (i.e., the LCST), but aggregates to form a second phase when the solution temperature is increased above the LCST.

[0030] "Hydrophilic," as used herein, refers to a molecule that has a greater affinity, and therefore solubility, for water compared to organic solvents. The hydrophilicity of a compound can be quantified by measuring its partition coefficient between water (or a buffered aqueous solution) and a water-immiscible organic solvent (e.g., octanol, ethyl acetate, methylene chloride, or methyl tert-butyl ether). A compound is considered hydrophilic if, after equilibration, a greater concentration of the compound is present in water than in the organic solvent.

[0031] "Hydrophobic", as used herein, refers to a molecule that has a greater affinity, and therefore solubility, for organic solvents compared to water. The hydrophobicity of a compound can be quantified by measuring its partition coefficient between water (or a buffered aqueous solution) and a water-immiscible organic solvent (e.g., octanol, ethyl acetate, methylene chloride, or methyl tert-butyl ether). If, after equilibration, a greater concentration of the compound is present in the organic solvent than in water, the compound is considered hydrophobic.

[0032] As used herein, the term "treating" includes inhibiting, alleviating, preventing, or eliminating one or more symptoms or side effects associated with the disease, condition, or disorder being treated.

[0033] The terms "reduce", "inhibit", "alleviate" or "decrease" can be used relative to either a control, no other treatment or a treatment with a known degree of effectiveness. Those skilled in the art can easily identify and use appropriate controls for each experiment. For example, the reduced response in a subject or cell treated with a compound is compared to the response in a subject or cell not treated with the compound.

[0034] As used herein, the term "effective amount" or "therapeutically effective amount" refers to a dosage sufficient to treat, inhibit, or alleviate one or more symptoms of the disease state being treated, or otherwise provide the desired pharmacological and / or physiological effect. The exact dosage will vary according to various factors, such as subject-dependent variables (e.g., age, immune system health, etc.), the disease or disorder, and the treatment being administered. The effect of the effective amount can be relative to a control. Such controls are known in the art and discussed herein, and can be, for example, the state of the subject before or in the absence of administration of the drug or drug combination, or in the case of a drug combination, the effect of the combination can be compared to the effect of administration of only one of the drugs.

[0035] "Excipient" is used herein to include a compound that is not a therapeutically or biologically active compound. Thus, an excipient should be pharma- ceutically or biologically acceptable or relevant; for example, an excipient should generally be non-toxic to the subject. "Excipient" includes a single such compound, and is intended to include a plurality of compounds.

[0036] The term "osmolarity" as generally used herein refers to the total number of dissolved components per liter. Osmolarity is similar to molar concentration, but includes the total number of moles of species dissolved in a solution. An osmolarity of 1 Osm / L means that there is one mole of dissolved component per liter of solution. Some solutes (e.g., ionic solutes that dissolve in a solution) provide more than one mole of dissolved component per mole of solute in the solution. For example, NaCl provides more than one mole of dissolved component per mole of solute in the solution. + and Cl - thus providing 2 moles of dissolved components per mole of dissolved NaCl in solution. Physiological osmolarity is typically in the range of about 280 to about 310 mOsm / L.

[0037] The term "tonicity" as generally used herein refers to the osmotic pressure gradient resulting from the separation of two solutions by a semipermeable membrane. In particular, tonicity is used to describe the osmotic pressure created across a cell membrane when the cell is exposed to an outside solution. Solutes that can cross the cell membrane do not contribute to the final osmotic pressure gradient. Only those dissolved species that do not cross the cell membrane contribute to the osmotic pressure difference, and therefore tonicity. The term "hypertonic" as generally used herein refers to a solution that has a higher solute concentration present inside the cell. When a cell is immersed in a hypertonic solution, water tends to flow out of the cell to balance the concentration of the solute. The term "hypotonic" as generally used herein refers to a solution that has a lower solute concentration present inside the cell. When a cell is immersed in a hypotonic solution, water flows into the cell to balance the concentration of the solute. The term "isotonic," as generally used herein, refers to a solution in which the osmotic gradient across the cell membrane is essentially balanced. An isotonic formulation is one that has essentially the same osmotic pressure as human blood. Isotonic formulations generally have an osmotic pressure of about 250-350 mOsm.

[0038] II. Hypotonic Gel-Forming Compositions Hypotonic formulations of hydrogel-forming polymers, preferably containing poloxamers, have been developed for enhanced delivery of therapeutic, diagnostic, prophylactic or other agents to epithelial tissues through mucus. The polymers are administered at concentrations below their normal critical gelling concentration (CGC). Poloxamer gels administered to the vagina or colorectum at concentrations equal to or above their CGC form a gel "plug" in the lumen. In contrast, fluid from a hypotonically administered poloxamer solution is absorbed into mucosal tissues when the poloxamer is at a concentration below its CGC, thereby pulling the poloxamer through the mucus gel toward the epithelium, thereby enhancing and facilitating delivery of the agent to the body. As water is absorbed into the tissue, the poloxamer concentrates near the epithelial tissue surface and gels, thereby trapping the drug molecules in a sustained-release gel on the tissue surface (rather than gel forming primarily in the lumen, as occurs, for example, in traditional thermogelling methods, whereby the gelling polymer is administered at a concentration at or above their CGC). Endogenous mucin glycopolymers affect the gelling properties of the hypotonic gelling agent, including the concentration of gelling agent required to gel and the pore structure of the resulting gel / mucin mixture. Following vaginal, colorectal, or ocular application, the hypotonic gelling vehicle coats the epithelium, including the folds or inside the eyelids.

[0039] The example shows longer vaginal retention of the model drug administered in a hypotonic gelling agent compared to a bolus of gel formed in the center of the vaginal lumen, as was the case for the CGC-administered gelling agent. In the case of ocular administration, the hypotonic gelling agent forms a uniform gel coating on the ocular surface, rather than the gelling agent in a bolus that is quickly cleared by blinking.

[0040] Described herein are gel-forming compositions that can form a uniform gel coating on an epithelial surface but do not gel under storage conditions, comprising one or more gel-forming polymers in a hypotonic carrier, optionally with one or more additional excipients and / or one or more therapeutic, prophylactic, or diagnostic agents.

[0041] A. Hydrogel-Forming Polymers The hypotonic gel-forming composition includes one or more gel-forming polymers that are utilized at a concentration below the normal critical gel concentration (CGC) of the polymer, e.g., a concentration at which a solution of the polymer gels in a test tube when warmed to 37°C.

[0042] A temperature-sensitive (also known as thermoresponsive) hydrogel is a solution that undergoes a sol-gel transition when the following criteria are met in both: 1) at or above the critical gelling concentration (CGC), and 2) At or above its critical gelation temperature.

[0043] Thermosensitive gelators used in biomedical applications (at concentrations at or above their CGC) are liquid at room temperature but form gels at body temperature. An increase in temperature induces rearrangement and alignment of the polymer chains, resulting in gelation into a three-dimensional structure. This phenomenon is generally governed by the ratio of hydrophilic to hydrophobic moieties on the polymer chain. A common feature is the presence of hydrophobic methyl, ethyl, or propyl groups. Thermosensitive polymers that meet these criteria can be administered topically to mucosal tissues in hypotonic solutions ranging in concentration below their CGC to form a uniform gel coating in vivo.

[0044] Examples of temperature-sensitive gel formers that can be used include: polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymers (e.g., those designated by the CTFA as Poloxamer 407 (CAS 9003-11-6, Poloxamers include, but are not limited to, poloxamers also known by the trade name PLURONIC®, e.g., PLURONIC® F98 (CAS 9003-11-6, molecular weight 13000 g / mol, percentage of polyoxyethylene of approximately 80% by weight; available from BASF); Poloxamers are also known by the trade name PLURONIC®, e.g., PLURONIC® F98 (CAS 9003-11-6, molecular weight 13000 g / mol, percentage of polyoxyethylene of approximately 80% by weight; available from BASF); Tetronics tetrafunctional block copolymers based on ethylene oxide and propylene oxide, commercially available from BASF as TETRONIC®; poly(N,N-diethylacrylamide); poly(N,N-dimethylacrylamide); poly(N-vinylcaprolactam); poly(N-alkylacrylamides); poly(N-vinylalkylamides); poly(N-isopropylacrylamide); polyethylene oxide methacrylate polymers; poly(lactic acid-co-glycolic acid) (PLGA)-polyethylene glycol triblock copolymers (PLGA-PEG-PLGA and PEG-PLGA-PEG); polycaprolactone (PCL)-polyethylene glycol triblock copolymers (PCL-PEG-PCL and PEG-PCL-PEG); chitosan; and combinations thereof.

[0045] The hydrogels can be formed from individual gel formers or as a combination of gel formers. For example, a poloxamer and another gel former (e.g., a tetronic polymer) can be used in combination to achieve desired properties. Furthermore, various forms of the same gel former (e.g., poloxamer 188 and poloxamer 407) can be combined to achieve desired properties.

[0046] The polymer is provided at a concentration less than that in an aqueous solution that forms a gel in a test tube when heated to 37° C. The concentration must be high enough, but below the CGC, so that the epithelium can absorb enough fluid for the CGC to be achieved in vivo, so that gelation occurs preferentially on / near the mucosal epithelial surface. The range of time it takes for gelation to occur depends on the mucosal surface (capacity and rate of water absorption), the tonicity of the administered solution (a more hypotonic solution drives more rapid fluid absorption), and the administered polymer concentration (if the polymer concentration is too low, not enough fluid absorption occurs to concentrate the polymer into the CGC). However, gelation generally occurs within an hour in the vagina and colorectum.

[0047] The concentration of the polymer and the presence of additional components (e.g., endogenous mucin) affect the coverage and rate and extent of gelation. 18% F127 gel mixed with purified porcine gastric mucin (1%) or human cervicovaginal mucus (1:1 ratio) does not capture virus-sized (approximately 100 nm) nanoparticles (polyethylene glycol-coated polystyrene nanoparticles, PSPEG) as effectively as 18% F127 gel alone. In contrast, 24% F98 gel captured PSPEG particles more effectively when mixed with mucin or human cervicovaginal mucin. However, in vivo virus capture with hypotonic gelling agents was more effective at capturing viruses, including human immunodeficiency virus (HIV, approximately 120 nm) and herpes simplex virus (HSV, approximately 180 nm). Administration of a hypotonic solution containing 18% F98 and with 24% CGC resulted in effective capture of subsequently administered HIV in the vagina. Similarly, hypotonic solutions containing 10% and 15% F127 with CGC 18% were effective in reducing the MSD of HIV, indicating capture. Furthermore, both 15% F127 and 18% F98 reduced the spread of HSV administered subsequently in mouse vaginal mucus. The distribution of individual virus MSDs on the 1 second time scale illustrated that the virus capture (shift to the left) was more uniform in the gel formed by the hypotonic 18% F98 vehicle compared to 15% F127. In further testing of virus capture by hypotonic gelling agents in the colorectum, we found that 12% F98 (CGC 24%) did not effectively capture PSPEG nanoparticles administered 30 minutes after the gelling vehicle, while 18% F98 was effective in capturing PSPEG nanoparticles in the mouse colorectum. Importantly, these examples demonstrate the differences in the gels that form when the hypotonic gelling agent is administered to different mucosal surfaces (in this case, mixing with vaginal mucus compared to colorectal mucus prior to gelling).

[0048] B. Hypotonic Carriers The gel-forming composition includes a hypotonic carrier. The hypotonic carrier is typically a biocompatible carrier that preferably causes little or no signs of irritation when administered to a human subject. The carrier can be naturally occurring or non-naturally occurring, including both synthetic and semi-synthetic carriers. The preferred carrier is water-based. Other solutions, including sugar-based (e.g., glucose, mannitol) solutions, and various buffers (phosphate buffers, Tris buffers, HEPES) can also be used.

[0049] When a hypotonic solution is applied to an epithelial surface, a fluid shift occurs and water moves into the epithelial tissue. This can cause swelling of epithelial cells. In some cases, if the osmotic difference is too great, epithelial cells can burst, causing tissue irritation or disruption of the epithelial membrane.

[0050] A hypotonic solution refers to a solution that causes water absorption by the epithelial surface to which it is administered. Examples of hypotonic solutions include, but are not limited to, tris[hydroxymethyl]-aminomethane hydrochloride (Tris-HCl, 10-100 mM, pH 6-8), (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES, 10-100 mM, pH 6-8), and dilute solutions of PBS (e.g., a solution containing 0.2 g KCl, 0.2 g KH2PO4, 8 g NaCl, and 2.16 g Na2HPO4*7H2O in 1000 ml H2O).

[0051] The hypotonic carrier causes the dissolved gel-forming polymer to concentrate at the epithelial surface, resulting in the formation of a uniform gel at the surface. The hypotonic carrier usually contains water as a major component. The hypotonic carrier can be water, but a mixture of water and a water-miscible organic solvent can also be used. Suitable water-miscible organic solvents include alcohols (e.g., ethanol, isopropanol); ketones (e.g., acetone); ethers (e.g., dioxane); and esters (e.g., ethyl acetate).

[0052] The hypotonic carrier can be distilled water with one or more osmolarity-modifying excipients. Sodium chloride is the excipient most frequently used to adjust osmolarity when the solution is hypotonic. Other excipients used to adjust hypotonic solutions include glucose, mannitol, glycerol, propylene glycol and sodium sulfate. Osmolarity-modifying excipients can include pharma- ceutically acceptable salts (e.g., sodium chloride, sodium sulfate, potassium chloride, and other salts that make buffers, such as sodium phosphate dibasic, potassium phosphate monobasic, calcium chloride, and magnesium sulfate). Other excipients used to adjust tonicity can include glucose, mannitol, glycerol, or propylene glycol.

[0053] The hypotonic carrier may have any osmolality below the effective isotonicity point at the mucosal surface (the concentration at which fluid is neither absorbed nor secreted by the underlying tissue). The isotonicity point varies for different mucosal surfaces and different buffers depending on the active ion transport at the epithelial surface; for example, the inventors have found that in the vagina for sodium-based solutions the isotonicity point is about 300 mOsm / L, while in the colorectum it is about 450 mOsm / L. In some embodiments, the solution has a tonicity of 50 mOsm / L to 280 mOsm / L, 100 mOsm / L to 280 mOsm / L, 150 mOsm / L to 250 mOsm / L, 200 mOsm / L to 250 mOsm / L, 220 mOsm / L to 250 mOsm / L, 220 mOsm / L to 260 mOsm / L, 220 mOsm / L to 270 mOsm / L, or 220 mOsm / L to 280 mOsm / L.

[0054] The hypotonic carrier may contain one or more pharma- ceutically acceptable acids, one or more pharma-ceutically acceptable bases, or salts thereof. Pharmaceutically acceptable acids include hydrobromic acid, hydrochloric acid, and sulfuric acid, as well as organic acids such as methanesulfonic acid, tartaric acid, and malic acid. Pharmaceutically acceptable bases include hydroxides of alkali metals (e.g., sodium or potassium) and alkaline earth metals (e.g., calcium or magnesium), as well as organic bases (e.g., pharma-ceutically acceptable amines). The hypotonic carrier may contain a pharma-ceutically acceptable buffer (e.g., citrate buffer or phosphate buffer).

[0055] C. Further Drugs The hypotonic gel-forming composition may contain one or more agents to be delivered. Examples include therapeutic agents, prophylactic agents, diagnostic agents, and / or functional nutritional factors. Biologically active agents are substances used in the treatment (e.g., therapeutic agents), prevention (e.g., prophylactic agents), diagnosis (e.g., diagnostic agents), or to effect a cure or alleviation of a disease or illness, or to alter the structure or function of the body, or prodrugs that become biologically active or more active after being placed in a given physiological environment. They may be small molecule drugs (e.g., molecular weights of less than 2000, less than 1500, less than 1000, less than 750, or less than 500 atomic mass units (amu)), peptides or proteins, sugars or polysaccharides, nucleotides or oligonucleotides (e.g., aptamers, siRNAs, and miRNAs), lipids, glycoproteins, lipoproteins, or combinations thereof.

[0056] The agents may include one or more of those listed in Martindale: The Complete Drug Reference, 37th Edition (Pharmaceutical Press, London, 2011).

[0057] In one embodiment, the drug to be delivered is poorly soluble in water but soluble in the carrier comprising the gelling polymer. In another embodiment, the drug is water-soluble. Data also show that water-soluble drugs (e.g., brimonidine tartrate) that are soluble up to approximately 1 mg / mL can be beneficial.

[0058] The hypotonic gel-forming formulation may include a therapeutically effective amount of a therapeutic agent to treat, inhibit, or alleviate one or more symptoms of the disease state being treated.The hypotonic gel-forming composition may include a therapeutically effective amount of a prophylactic agent to prevent one or more symptoms of a disease or disorder.

[0059] The agent may be an anti-infective agent (antibiotic, antiviral, antifungal), for the treatment of ocular disorders (glaucoma, dry eye), an anti-inflammatory agent (inhibits angiogenesis, fibrosis), for contraception, for the treatment of metabolic disorders, for the treatment of heartburn or ulcers, for the treatment of cardiovascular disorders (e.g., hypertension and atherosclerosis), a neuroactive agent, or a chemotherapeutic agent for the treatment of diseases such as cancer.

[0060] Exemplary agents include brinzolamide, cyclosporine A, brimonidine tartrate, moxifloxacin, budesonide, sunitinib, and acriflavine.

[0061] Examples of useful proteins include hormones (e.g., insulin, growth hormones including somatomedins, and reproductive hormones). Examples of useful drugs include neurotransmitters (e.g., L-DOPA), blood pressure reducing agents or saluretics (e.g., Metolazone from Searle Pharmaceuticals), carbonic anhydrase inhibitors (e.g., Acetazolamide from Lederle Pharmaceuticals), insulin-like drugs (e.g., glyburide), sulfonylurea class hypoglycemic agents, synthetic hormones (e.g., Android F from Brown Pharmaceuticals and TESTRED® (methyltestosterone) from ICN Pharmaceuticals). Representative anti-proliferative (anti-cancer or endometriosis) agents include, but are not limited to, alkylating agents (e.g., cisplatin, carboplatin, oxaliplatin, mechlorethamine, cyclophosphamide, chlorambucil, dacarbazine, lomustine, carmustine, procarbazine, chlorambucil, and ifosfamide), antimetabolites (e.g., fluorouracil (5-FU), gemcitabine, methotrexate, cytosine arabinoside, fludarabine, and floxuridine), antimitotic agents (taxanes (e.g., paclitaxel and docetaxel) and vinca alkaloids (e.g., vincristine, , vinblastine, vinorelbine, and vindesine), anthracyclines (including doxorubicin, daunorubicin, valrubicin, idarubicin, and epirubicin), and actinomycins (e.g., actinomycin D), cytotoxic antibiotics (including mitomycin, plicamycin, and bleomycin), topoisomerase inhibitors (including camptothecins (e.g., camptothecin, irinotecan, and topotecan)), and derivatives of epipodophyllotoxins (e.g., amsacrine, etoposide, etoposide phosphate, and teniposide), and combinations thereof.Other suitable anti-cancer agents include: angiogenesis inhibitors (antibodies against vascular endothelial growth factor (VEGF), such as bevacizumab (AVASTIN®), other anti-VEGF compounds); thalidomide (THALOMID®) and its derivatives (such as lenalidomide (REVLIMID®); endostatin; angiostatin; receptor tyrosine kinase (RTK) inhibitors (such as sunitinib (SUTEN®)); T®); tyrosine kinase inhibitors (e.g., sorafenib (NEXAVAR®), erlotinib (TARCEVA®), pazopanib, axitinib, and lapatinib); inhibitors of transforming growth factor-α or transforming growth factor-β, and antibodies against the epidermal growth factor receptor (e.g., panituzumab (VECTIBIX®) and cetuximab (ERBITUX®)).

[0062] For imaging, radioactive substances (e.g., technetium 99 ( 99m TC) or magnetic substances (e.g., labeled Fe2O3) can be used. Other examples of substances include compounds that are radiopaque.

[0063] III. Methods and Preparation of Hypotonic Gel-Forming Compositions Drug solubilization offers potential advantages including enhanced physical stability during storage, increased drug permeation into the body, and more reproducible drug dosing when administered to patients.

[0064] Water-insoluble drugs are particularly difficult to deliver to mucosal surfaces (e.g., mucosal surfaces of the eye, digestive tract, female genital tract, respiratory tract, etc.) due to lack of absorption. The formulation is particularly suitable for delivering therapeutic agents that are poorly water-soluble. Water-soluble drugs are also difficult to deliver to mucosal surfaces in a sustained manner. Thus, the gelling material can also be used as a vehicle to improve mucosal absorption of water-soluble drugs, for example, by providing more sustained drug absorption, which can reduce side effects and provide longer-term efficacy.

[0065] Furthermore, mucosal surfaces are rapidly cleaned and regenerated as a normal defense mechanism against infection and foreign particulate matter.Improvement of drug solubilization can improve mucosal permeability, and improving the distribution, permeability and retention of hydrophobic drugs is a promising strategy to improve therapeutic efficacy.The following examples show the solubilization of various poorly water-soluble drugs and drug complexes into materials that also have temperature-sensitive gelling properties.

[0066] 1-4 show schemes for achieving direct drug solubilization of hydrophobic drugs and drug complexes into gelling materials.

[0067] FIG. 1 is a scheme for solubilization of a hydrophobic drug (e.g., cyclosporine A or budesonide) by the solvent evaporation method.

[0068] FIG. 2 is a scheme for solubilization of hydrophobic drugs (eg, moxifloxacin) by bead milling.

[0069] FIG. 3 is a scheme for solubilization of a hydrophobic drug (eg, cyclosporine A or brimonidine) by dialysis.

[0070] FIG. 4 is a scheme for solubilization of a hydrophobic drug (eg, Brinzolamide) by the solvent evaporation method.

[0071] Formulations may be prepared as described in the examples below.

[0072] The formulation can be prepared as a liquid for administration. The gel-forming liquid or polymer solubilizes insoluble drugs by forming micelles. Powders can be produced by lyophilization and reconstituted at the time of use.

[0073] The formulation may also include pharma- ceutically acceptable diluents, preservatives, solubilizers, stabilizers, emulsifiers, auxiliary substances, and / or carriers. Stabilizers (e.g., SPAN® 20 (sorbitan laurate, CAS number 1338-39-2) may promote dissolution and prevent reaggregation. Other exemplary stabilizers include polysorbates or TWEENS®, such as polysorbate 20, polysorbate 60, polysorbate 65, and polysorbate 80, as well as polyglycerol esters (PGE), polyoxyethylene alkyl ethers, poloxyl stearates, fatty acids (e.g., oleic acid), and propylene glycol monostearate (PGMS). In some cases, the composition includes one or more stabilizers.

[0074] Increased viscosity without shear can lead to increased residence time on the mucosal surface of the eye, while shear thinning during blinking maximizes comfort and lubrication. Thus, a gelling material with these properties can have favorable lubricating properties on the surface of the eye while resisting removal during blinking. In some examples, one or more polymeric materials are incorporated into the gelling vehicle to increase viscosity without shear and / or shear thinning during blinking. In one example, hydroxypropyl methylcellulose (HPMC) is incorporated into the F127 solution to achieve these desirable properties. In some examples, shear thinning polymers are also included in the composition in a concentration range where they conventionally exhibit shear thinning properties. Exemplary shear thinning polymers include cellulose derivatives (e.g., methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, etc.).

[0075] Dosage formulations are typically prepared as single or multiple liquid or dry dosage units in a suitable applicator. Those skilled in the art recognize many options for drug storage and application, such as dual-chambered devices that can be used to keep various components separate during storage. Multiple dose forms typically include a barrel loaded with the powder and a plunger having dosage increments thereon. These are typically sterilized and packaged in a sealed, sterilized package for storage and distribution. See also Remington: The Science and Practice of Pharmacy, 22nd Edition.

[0076] The dosage unit administrator can be designed to fit the anatomical location where the drug is to be delivered (eg, rectally, intravaginally, intranasally, or orally).

[0077] IV. Methods of Administering Hypotonic Gel-Forming Compositions The hypotonic gel-forming composition can in principle be applied to any water-absorbing surface, including skin and mucosal tissue, to form a gel. Preferably, the formulation is applied as a liquid to a mucosal covering on an epithelial surface of a subject in need of a therapeutic, prophylactic, diagnostic, or nutritional effect. The gel-forming composition can be applied in any number of ways known to those of skill in the art, so long as the hypotonic solution, or the reagents that form the hypotonic solution, come into contact with the surface.

[0078] By applying the gel-forming composition as a hypotonic formulation, water is absorbed into the epithelial tissue. Absorption of water provides concentration of the gel-forming polymer on the surface, resulting in uniform gel formation at the surface. The gel can act as a barrier, a reservoir, or a combination thereof. Drugs or excipients in the gel-forming composition can remain entrapped within the gel and can be released at or to the surface.

[0079] Epithelial surfaces include oral, pharyngeal, esophageal, pulmonary, ocular, aural, nasal, buccal, lingual, vaginal, cervical, urogenital, gastrointestinal, anorectal, and / or cutaneous surfaces.

[0080] In some examples, the hypotonic gel-forming composition maintains an effective concentration of one or more active agents at one or more mucosal surfaces for an extended period of time, such as for example, more than 6 hours, more than 12 hours, more than 1 day, more than 2 days, more than 3 days, more than 4 days, more than 5 days, more than 6 days, or more than 1 week.

[0081] In some cases, the hypotonic gel-forming composition increases the concentration of one or more active agents by 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, or more than 10-fold at or near the site of application compared to the active agents delivered without a gel-forming vehicle, e.g., in a saline solution. When the hypotonic gel-forming composition is applied to the eye, mucosal sites with increased concentrations of active agents include one or more of the cornea, aqueous humor, sclera, conjunctiva, iris, lens, retina, and retinal pigment epithelium.

[0082] In some examples, the hypotonic gel-forming compositions deliver 10%, 20%, 30%, 40%, 50%, or greater than 50% of the active agent (e.g., acriflavine and sunitinib malate) to the retina and / or choroid in an amount effective to reduce retinal and / or choroidal neovascularization compared to the active agent delivered without a gel-forming vehicle, e.g., in a saline solution.

[0083] In other examples, the hypotonic gel-forming composition delivers an active neuroprotective agent (e.g., sunitinib malate) to the retina in an amount effective to increase survival of retinal ganglion cells following optic nerve injury and / or increase expression of γ-synuclein and / or βIII tubulin in retinal ganglion cells following optic nerve injury by 2-fold, 3-fold, 4-fold, 5-fold, or more than 5-fold compared to the active agent delivered without a gel-forming vehicle, e.g., in a saline solution.

[0084] In further examples, the hypotonic gel-forming composition delivers an active agent (e.g., brinzolamide) to the eye in an amount effective to reduce intraocular pressure (IOP) by 10%, 20%, 30%, 40%, 50%, or more than 50% in less than 2 hours, less than 4 hours, less than 6 hours, less than 8 hours, less than 10 hours, less than 12 hours, or less than 24 hours, compared to the active agent delivered without a gel-forming vehicle, e.g., in a saline solution.

[0085] In other examples, the hypotonic gel-forming composition delivers an active agent (e.g., cyclosporine A) to the eye in an amount effective to increase tear production by 10%, 20%, 30%, 40%, 50%, or more than 50% in less than 2 hours, less than 4 hours, less than 6 hours, less than 8 hours, less than 10 hours, less than 12 hours, or less than 24 hours compared to the active agent delivered without a gel-forming vehicle, e.g., in a saline solution.

[0086] The invention will be further understood by reference to the following non-limiting examples. EXAMPLES

[0087] Example 1: Cyclosporine A eye drops Rapid drug clearance from the ocular surface is a major obstacle to localized drug delivery, and as a result, many eye drops are prescribed for application several times daily.

[0088] material and method The first example embodies the solubilization of Cyclosporine A (used for dry eye) (gelCsA) in a temperature-sensitive gelling vehicle prepared using the method shown diagrammatically in Figure 3. Cyclosporine A and Pluronic F127 (10-18% w / w) were dissolved together in DMSO and dialyzed against water equilibrated with salt (sodium chloride, final osmolality 200 mOsm) for 2 days to remove the DMSO. The CsA concentration in all the formulations was 0.05%. Tear production was measured using Schirmer test strips held in contact with the ocular surface. Drug concentration was measured using LC-MS.

[0089] result It has been reported in the literature that cyclosporine increases tear production in the eyes of healthy animals. Figure 5A shows the cumulative increase in tear production induced by cyclosporine in healthy rabbit eyes over 12 hours after a single instillation of cyclosporine A formulated in various concentrations of Pluronic F127 (including 10%, 12%, 15%, and 18% w / w). The hypotonic 12% F127 vehicle of cyclosporine provided the greatest increase in tear production.

[0090] FIG. 5B is a graph of tear production in healthy rabbit eyes 10 hours after each of five daily doses of gelCsA, gel vehicle (no drug), RESTASIS®, RESTASIS® vehicle (Refresh Endura), or no treatment (untreated). Only in the case of gelCsA is tear production due to cyclosporine delivery observed 10 hours after administration of the eye drops. This further illustrates the feasibility of administering gelCsA once a day, whereas RESTASIS® is prescribed twice a day.

[0091] 5C and D show cyclosporine levels in rat corneal and conjunctival tissues after administration of various cyclosporine eye drops, demonstrating that hypotonic gelCsA provides superior cyclosporine delivery compared to isotonic and conventional gel vehicles, as well as RESTASIS®.

[0092] Example 2: Brinzolamide eye drops for the treatment of glaucoma material and method Brinzolamide is used to lower intraocular pressure (IOP) as a treatment for glaucoma. Brinzolamide was formulated in its gelling vehicle (gelBRZ) using the method of Figure 4. Pluronic F127 ranged from 10-18% and salt was added to adjust osmolality to isotonicity (300 mOsm / kg) where needed. The effect of the vehicle itself (gelBRZ vehicle) and Brinzolamide eye drops on IOP in normotensive rabbits was tested after administration of a single eye drop of 50 μL at 10 mg / mL.

[0093] result FIG. 6A is a graph showing gelBRZ formulated as either a conventional (18% F127) gelling material or a lower concentration (12% F127) formulated to be either hypotonic or isotonic. FIG. 6B shows that the gelBRZ vehicle had no effect on IOP in the treated or contralateral eye in normotensive rabbits. It further compares the hypotonic gelBRZ formulation to the commercially available eye drop AZOPT® (1% brinzolamide clinical ophthalmic suspension). A dose of 1% brinzolamide significantly increased IOP in the treated eye compared to AZOPT® with gelBRZ (12%, When delivered as a hypotonic gelBRZ, it had a more pronounced effect on IOP lowering for up to 8 hours after treatment. Furthermore, hypotonic gelBRZ (35 mOsm) lowered IOP more than isotonic gelBRZ (300 mOsm) at early time points up to 4 hours.

[0094] Example 3: Brimonidine Tartrate Ophthalmic Formulation material and method Brimonidine tartrate is a water-soluble drug that can be dissolved directly into a gelling vehicle (gelBT). We first tested whether there was an optimal F127 concentration for administering brimonidine tartrate to the eye in a hypotonic gelling vehicle, as measured by IOP reduction in normotensive rabbits. IOP reduction was then compared for F127 concentrations ranging from 12-18% in hypotonic (no salt) and isotonic (adjusted to 300 mOsm / kg with salt) in normotensive rabbits. Drug concentrations were measured by LC-MS. result

[0095] Figure 7A shows the cumulative change in IOP over 8 hours after administration of brimonidine tartrate 0.15% (gelBT) in F127 (10-18%). The cumulative reduction in IOP over 8 hours after a single instillation of hypotonic gelBT in normotensive rabbits was highest for gelBT containing 12% F127. Figure 7B shows that compared to isotonic (12% F127) and conventional (18% F127) eye drops, hypotonic gelBT was more effective in lowering IOP over an 8-hour period in normotensive rabbits. Figure 7C shows that gelBT vehicle had no effect on IOP and hypotonic gelBT was more effective than commercial Alphagan eye drops in lowering IOP over an 8-hour period. Figures D-F show BT levels in the cornea, conjunctiva, and aqueous humor of rats 1, 4, and 8 hours after the last dose (administered 2x daily for 5 days). Drug levels were higher in hypotonic gelBT than all other formulations. Figure 7G shows that even at mild hypotonicity (200 mOsm), gelBT was effective in lowering IOP.

[0096] Example 4: Incorporation of polymeric materials into gelling vehicles material and method Polymeric substances were incorporated into the gelling vehicle, hydroxypropylmethylcellulose (HPMC), into the F127 solution (due to shear thinning properties), which may be advantageous when blinking (ocular administration) or lubricating (rectal administration). The polymeric substances may also increase the viscosity of the gel at rest (without shear) and improve retention time on mucosal surfaces.

[0097] result As shown in FIG. 8A, the addition of 0.5% HPMC to F127 increases the viscosity under low / no shear, which is already several thousand times higher than a standard lubricating eye drop (GENTEAL®). FIG. 8B shows that the shear thinning properties (reduction in viscosity when placed under shear) are similar for F127 solutions containing HPMC compared to standard lubricating eye drops (GENTEAL®). Thus, the addition of hydroxypropyl methylcellulose (HPMC) to F127 solutions increases the viscosity under low / no shear while maintaining the low viscosity observed in standard lubricating eye drops (e.g., GENTEAL®) under high shear (similar to the shear rate when blinking).

[0098] The increased viscosity without shear can lead to increased residence time on the mucous surface of the eye, while the shear thinning during blinking maximizes comfort and lubrication.Thus, such gelling materials can have favorable lubricating properties on the surface of the eye while resisting removal during blinking.Materials include shear thinning polymers, such as cellulose derivatives (e.g., methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, etc.), in a concentration range that conventionally exhibits shear thinning properties.

[0099] Example 5: No Ocular Irritation in the Presence of Hypotonic Gelling Vehicles with Various Osmolalities New Zealand White rabbits were administered 50 μL per eye drop twice daily for 5 weeks to assess potential ocular irritation. Test agents included 12% F127 solution containing sodium chloride to produce final osmolalities ranging from no added salt to 300 mOsm / kg. The negative control was balanced salt solution (BSS) with a group of animals receiving no treatment. There were no differences in corneal staining (lisamine green 1%) or blink rate (number of blinks in 3 minutes) for any formulation compared to untreated animals.

[0100] Example 6: Drug delivery to the retina / choroid via topical administration C57 / B6 mice were used to test the local delivery of sunitinib malate (5 μL at 4 mg / mL) and acriflavine (5 μL at 5 mg / mL) in preventing choroidal neovascularization (CNV) in mice following laser-induced disruption of Bruch's membrane at three sites. Both drugs, dissolved in either 12% F127 or aqueous vehicle control (saline or water), were administered daily for 7 days after laser. Only the formulation containing F127 was effective in inhibiting neovascularization in the choroid.

[0101] Example 7: Melanin-binding long-term therapeutic effects of sunitinib administered topically in a hypotonic gelling vehicle following optic nerve injury Rats were given daily topical unilateral administration of sunitinib malate (5 μL at 4 mg / mL) in 12% F127 for 5 days. The optic nerve head was then exposed and crushed on one side, with the contralateral eye used as a control for comparison. 14 days after nerve crush (without further topical administration), the tissue was isolated for qPCR on genes expressed by retinal ganglion cells (RGCs). This administration scheme resulted in protection of RGCs in pigmented (Brown Norway) and non-pigmented (Wistar) rats, suggesting that binding to melanin in the eye resulted in a long-term therapeutic effect.

[0102] Example 8: Treatment of Optic Nerve Injury Using a Hypotonic Gelling Vehicle Pigmented rats (Brown Norway) were given topical unilateral administration of sunitinib malate (5 μL at 4 mg / mL) in 12% F127 or in saline once a week. The optic nerve head was exposed and crushed unilaterally on day 8, with the contralateral eye used as a control for comparison. 14 days after nerve crush (day 22), the tissue was isolated for qPCR of genes expressed by retinal ganglion cells (RGCs). Protection of RGCs was only observed when sunitinib malate was administered in 12% F127, but not when sunitinib malate was administered in saline.

[0103] Example 9: Ocular tissue distribution of therapeutic agents delivered in a hypotonic gelling vehicle material and method Sunitinib malate was dissolved in 12% F127 at a concentration of 4 mg / ml and administered topically once daily to pigmented rabbits (Dutch breed) and pigmented pigs (young domestic pigs) for a total of 14 or 5 days, respectively. Both rabbit and piglet administrations were performed without anesthesia, administering 50 μL or 50-100 μL eye drops, respectively. However, pig administrations were performed while distracted with food. Tissues were collected 6 hours after the last administration for rabbits and 1 hour after the last administration for pigs. The drug concentrations were measured by LC-MS.

[0104] result Sunitinib malate was administered topically in its hypotonic gelling vehicle to (Figure 9A) Dutch rabbits daily for 14 days and (Figure 9B) domestic pigs daily for 5 days. Tissues were isolated and sunitinib and the main metabolite (N-desethylsunitinib) levels were quantified in various ocular tissues and fluids. Therapeutically relevant levels of the drug were found in the anterior and posterior segments of the eye.

[0105] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference.

[0106] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein which equivalents are intended to be encompassed by the following claims.

Claims

1. 1. A formulation for delivery of a therapeutic agent, a prophylactic agent, a diagnostic agent, or a functional nutritional factor, the formulation maintaining an effective concentration of the therapeutic agent, the prophylactic agent, the diagnostic agent, or a functional nutritional factor at an epithelial or mucosal surface in or on the eye to treat, prevent, or diagnose an ocular disease, the formulation comprising: Therapeutic agents, preventive agents, functional nutritional factors or diagnostic agents, a gel-forming polymer for application to the eye, the gel-forming polymer being formulated such that the gel-forming polymer is at a concentration below the critical gel concentration (CGC) of the polymer under isotonic conditions and at a temperature between 25° C. and 37° C.; and excipients for forming a pharma- ceutically acceptable hypotonic formulation of said polymer suitable for delivery to the eye of an individual in need thereof; Including, wherein the polymer is a poloxamer and the formulation is hypotonic; The formulation is administered to an epithelial or mucosal surface in or on the eye.

2. The formulation of claim 1 , wherein the gel-forming polymer is a temperature-sensitive gel-forming polymer.

3. 3. The formulation of claim 2, wherein the temperature sensitive gel-forming polymer has a lower critical solution temperature of less than 30°C.

4. 4. The formulation of claim 3, wherein the temperature sensitive gel-forming polymer has a lower critical solution temperature of less than 21°C.

5. The formulation of any one of claims 1 to 4, wherein the polymer in combination with excipients forms a gel on a mucosal or epithelial surface in or on the eye.

6. The formulation of any one of claims 1 to 5, wherein the therapeutic agent, prophylactic agent, diagnostic agent or functional nutritional factor is water soluble.

7. The formulation of any one of claims 1 to 5, wherein the therapeutic agent, prophylactic agent, diagnostic agent or functional nutritional factor is poorly water soluble.

8. The formulation of any one of claims 1 to 7, wherein the gel-forming polymer is between greater than 12% and less than 24% PLURONIC® F98 in the aqueous vehicle.

9. The formulation of any one of claims 1 to 7, wherein the gel-forming polymer is between 10 and 18% PLURONIC® F127.

10. The formulation of any one of claims 1 to 9, wherein the gel-forming polymer forms a uniformly thick layer upon administration onto the epithelial surface.

11. The formulation according to any one of claims 1 to 10, wherein the formulation is provided in a single dosage unit or in multiple dosage units for administration.

12. 12. The formulation of any one of claims 1 to 11, wherein the therapeutic agent, prophylactic agent, diagnostic agent or functional nutritional factor is a protein or peptide, a sugar or polysaccharide, a lipid, a glycolipid, a glycoprotein, a nucleic acid, an oligomer or polymer thereof, or a small molecule.

13. 12. The formulation of any one of claims 1 to 11, wherein the therapeutic agent, prophylactic agent, diagnostic agent or functional nutritional factor is selected from the group consisting of steroids, glaucoma agents, tyrosine kinase inhibitors, immunosuppressants, anti-fibrotic agents, anti-infective agents, hormones and chemotherapeutic agents.

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