Local delivery of antifungal agents for the treatment of fungal infections - Patent Application 20070122999

Abstract

The present disclosure provides formulations for the local delivery of antifungal agents into keratinous tissue, such as the nails and / or skin, for the treatment of various fungal infections.

Description

[Technical Field]

[0001] The present disclosure relates to formulations for the local delivery of antifungal agents into keratinous tissue (eg, nails and / or skin). [Background technology]

[0002] Listed below are references believed to be relevant to the background of the subject matter disclosed herein: References [1] K Foster et al., J Am Acad Dermatol 2004, 50, 748-752 [2] AB Youssef et al., J Mycol Med. 2018, 28(4), 651-654 [3] A Shemer, Dermatol. Ther. 2012, 25(6), 582-593 [4] BM Piraccini et al., Skin Appendage Disord. 2018, 5(1), 13-19 [5] AK Gupta, Expert Rev. Anti Infect. Ther. 2018, 16(12), 929-938 [6] M Johnson et al., British Journal of Dermatology 1994, 130, 195-198 [7] VK Bhatia et al., Indian Journal of Medical Microbiology 2015, 33(4), 533-537 [8] VK Maurya et al., J. Fam. Med. Prim. Care 2019, 8(8), 2577 [9] PCT patent application publication no. WO2020 / 255114

[0003] No admission of any relevance whatsoever to the patentability of the subject matter disclosed herein should be inferred from the admission of any of the contents of the above references cited herein.

[0004] background Onychomycosis, or Tinea unguium, is a chronic fungal infection of the nail unit that affects 2–18% of the world's population. The known incidence increases with the level of immunocompromise (e.g., diabetes), age (prevalence is 0.2–2.6% in children compared to 48% in those over 70 years of age), or trauma to the nail unit [1].

[0005] The most common cause of onychomycosis is Trichophyton rubrum, but other fungal skin pathogens, including Trichophyton mentagrophytes and Epidermophyton floccosum, can also cause onychomycosis. These dermatophytes are identified in 90% of toenail and 50% of fingernail onychomycosis cases. Candida albicans accounts for 2% of onychomycosis cases, particularly in the fingernails. Nondermatophyte onychomycosis is primarily cultured from toenails. Examples of these saprophytic fungi include Fusarium, Aspergillus, Acremonium scytalidium, and Scopulariopsis brevicaulis. These fungi account for approximately 8% of nail infections. [2]

[0006] Distal marginal subonychia is the most common clinical subtype. In distal marginal subonychia, fungal invasion begins in the hyponychium, then progresses to the distal nail bed and then the nail plate.[3] Clinically, distal marginal subonychia presents as yellowish, whitish, or brownish discoloration of the distal corner of the nail. Distal marginal subonychia hyperkeratosis, onycholysis, and / or macroonychia of the lateral and distal aspects of the nail plate are common.[3]

[0007] Topical antifungal therapy includes the use of topical antifungal agents as well as nail and skin lacquers and solutions. Commonly used topical antifungal agents include efinaconazole (Jublia, Clenafin) (10% nail solution), tavaborole (Kerydin) (5% nail solution), ciclopirox (Ciclodan, Penlac, Loprox) (8% nail lacquer or hydrolacquer), amorolfine (Curanail, Loceryl, Locetar, Odenil) (5% nail lacquer), and terbinafine (Lamisil) (1% nail solution).[4] Generally, topical antifungals are well tolerated; adverse events are minimal and include periungual erythema and tingling at the application site.[5]

[0008] Oral antifungal agents are the gold standard for treating onychomycosis, with mycological and complete cure rates of 70% and 38%, respectively. Systemic medications have very low efficacy (average complete cure rate of 3% to 7%) and are associated with potentially severe adverse effects and drug-drug interactions. Treatment failure rates (20% to 50%) and recurrence rates (10% to 53%) are high and increasing. Due to the lack of systemic adverse exposure, topical antifungals may be preferable to systemic agents. Summary of the Invention

[0009] The present disclosure provides a formulation for topical delivery of an antifungal agent to stratum corneum for sustained delivery of the antifungal agent to stratum corneum. The formulation described herein is in the form of nanodomains dispersed in an aqueous phase, has a viscosity suitable for topical application of the formulation to stratum corneum as a thin layer, and is formulated to form a film on the stratum corneum upon application and evaporation of the solvent / water, with a residence time of at least several hours, e.g., up to 24 hours. The film present on the tissue after application contains antifungal agent-containing nanodomains, which enable sustained release of the antifungal agent into the tissue during contact between the film and the tissue. That is, after application, the formulation forms a depot (reservoir) that supplies the antifungal agent to the tissue. Furthermore, the size and composition of the nanodomains enable effective local delivery of the antifungal agent to the stratum corneum without significant systemic exposure. As further described below, it has also been unexpectedly discovered that the formulations of the present disclosure allow for enhanced penetration and diffusion of the antifungal agent into the stratum corneum, thereby delivering the antifungal agent not only to the area of ​​tissue to which the formulation is applied, but also to adjacent tissue areas deeper and laterally to the stratum corneum, thereby enabling effective treatment of fungal-infected tissue.

[0010] In one aspect, the present disclosure provides a formulation for topical delivery of an antifungal active agent to keratinous tissue, the formulation comprising nano-domains dispersed in an aqueous continuous phase. The nano-domains comprise the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol, while the aqueous phase comprises water, at least one film-forming agent in an amount of about 1 wt% or less, and at least one keratolytic agent. The total amount of water in the formulation is about 35 wt% to about 55 wt%.

[0011] The formulations of the present disclosure are liquid formulations having nano-domains, i.e., nanostructures composed of nano-droplets, which contain and stabilize the antifungal active agent and the aqueous continuous phase in which the nano-domains are dispersed. The nano-domains typically have an average size of 100 nm or less, more typically 50 nm or less, and the droplets do not prevent visible light from passing through the formulation, making the formulation transparent.

[0012] In some embodiments, the nanodomains have an average size of about 100 nm (nanometers) or less. In other embodiments, the nanodomains have an average size of about 50 nm or less. According to some embodiments, the nanodomains have an average size of about 1 to about 25 nm.

[0013] According to some embodiments, the formulation is in the form of nanodomains uniformly dispersed in an aqueous phase. The formulation is a system in which droplets, typically nanometer-sized droplets and structures, spontaneously self-assemble, and the nanodomains formed in the formulation are both kinetically and thermodynamically stable. In other words, the components of the system do not need to be subjected to high-intensity mixing or shear force to be arranged in the form of uniformly dispersed nanodroplets in the continuous phase. In the formulation of the present disclosure, the balance between the at least one hydrophilic surfactant, at least one alcohol, and at least one polyol makes it possible to obtain droplets with substantially zero interfacial energy, thereby inducing the spontaneous arrangement of these components into energetically favorable nanostructures that are stable both kinetically and thermodynamically.

[0014] According to some embodiments, the formulation is in the form of nano-domains dispersed in a continuous aqueous phase. In contrast to emulsion systems that are oil-rich, whereby the active agent typically dissolves within the oil core, the absence of oil in the formulations disclosed herein forces the antifungal agent to be trapped within the surfactant tails and reside at the interface between the nano-domains and the aqueous phase. Such solubilization within the interface results in a thermodynamically very stable formulation that does not undergo phase separation or release the antifungal agent from the nano-droplets over long periods of time, but only allows the active agent to be released from the formulation upon contact with keratinous tissue.

[0015] Thus, in some embodiments, the formulation comprises up to 1 wt% oil, while in other embodiments, the formulation is devoid of oil.

[0016] The formulation is designed to deliver antifungal active agent to keratinous tissue.The term "antifungal active agent" is intended to refer to one or more chemical entities that have the effect of delaying, stopping, reducing and / or inhibiting at least one effect associated with fungal contamination in keratinous tissue.The activity of the antifungal agent can be achieved by therapeutic or prophylactic methods.The antifungal active agent referred to herein has at least one effect of improving the undesirable symptoms associated with fungal infection, preventing the symptoms before such symptoms appear, slowing down the progression of fungal infection, promoting the onset of remission, slowing down the irreversible damage that occurs in the advanced stage of infection, delaying the onset of the advanced stage, reducing the severity or curing the infection, or preventing recurrence of infection, or a combination of two or more of the above.

[0017] According to some embodiments, the antifungal agent is selected from polyenes (such as amphotericin B and nystatin), azoles (such as itraconazole, fluconazole, efinaconazole, ketoconazole, and miconazole), allylamines (such as terbinafine and butenafine), and other synthetic and naturally occurring molecules (including, but not limited to, ciclopirox, amorolfine, tavaborole, and griseofulvin), or any pharmaceutically acceptable salt, hydrate, derivative, or analog thereof.

[0018] In some embodiments, the antifungal is terbinafine or any suitable pharmaceutically acceptable salt thereof.

[0019] According to some embodiments, the antifungal active agent is present in the formulation in an amount of at least about 1 wt%. In other embodiments, the antifungal active agent is present in the formulation in an amount ranging from about 1 wt% to about 10 wt%.

[0020] The formulations are designed for topical administration to keratinous tissue, which is meant to include keratin-rich tissue such as the nail or the upper layer of skin surrounding the nail or nail bed.

[0021] According to some embodiments, the formulation is for use in treating a fungal infection in a human subject. In such embodiments, the keratinous tissue is at least one of the nail, nail bed, cuticle (cuticle of the nail), posterior nail fold (skin around the nail), hyponychium (skin under the nail plate), and hair.

[0022] According to other embodiments, the formulation is for veterinary use, e.g., for use in treating fungal infections in mammals or non-mammals, hi such embodiments, the keratinous tissue is at least one of nails, keratinous skin, hair (including animal hair and wool), horns, hooves, feathers, scales, and the like.

[0023] As described above, the nano-domains include at least one hydrophilic surfactant, at least one alcohol, and at least one polyol.

[0024] The hydrophilic surfactant is a surface-active substance having a hydrophilic head group and a lipophilic tail that can solubilize the antifungal active agent. The head group can physically and / or sterically interact with the antifungal active agent, the alcohol, and the polyol, thereby enabling the formation of the nano-domain. Depending on the antifungal active agent incorporated into the formulation, the hydrophilic surfactant can include ionic, cationic, zwitterionic, or nonionic surfactants with hydrophilic properties (i.e., with a large head group), thereby providing a surfactant that is compatible with water. Exemplary surfactants are ethoxylated fatty alcohols (cetosteareths, ceteths, oleths, steareths), polysorbates (polysorbate 20, 60, 80), ethoxylated fatty acids (ethoxylated stearates), ethoxylated (hydrogenated / non-hydrogenated) castor oil, ethoxylated glycerides of fatty acids, PEGylated octylphenyl ethers, sugar esters, polyglycerol esters, polyethylene glycols (PEG), copolymers of ethylene oxide (EO) and propylene glycol (PG) moieties, lysolecithins, and combinations thereof.

[0025] In some embodiments, the formulation comprises at least two hydrophilic surfactants, i.e., at least a first hydrophilic surfactant and at least a second hydrophilic surfactant, wherein the first and second hydrophilic surfactants are different from each other. The oily phase comprises at least two hydrophilic surfactants. The hydrophilic surfactants are selected to be suitable for their combined form, a "Sherman complex." A Sherman complex refers to a set of two or more surfactants that form a dense, highly packed, compressed interfacial layer by combining two surfactants with two different lipophilic tails (i.e., one with a longer tail and the other with a shorter tail, and one embedded in the other at the core of the domain). In a Sherman complex, the two surfactants have hydrophilic head groups; one with a larger head group and the other with a smaller head group, forming strong hydrogen bonds between the head groups. Such a complex enhances the solubilization of the antifungal active agent in the nano-domain and provides better chemical stabilization of the antifungal active agent within the surfactant tail.

[0026] According to some embodiments, each of the first and second hydrophilic surfactants is independently selected from polysorbates (ethoxylated sorbitan fatty acid esters), ethoxylated fatty alcohols (e.g., Brijs), ethoxylated castor oils, ethoxylated glycerides of fatty acids, ethoxylated fatty acids, and combinations thereof.

[0027] According to some embodiments, the formulation comprises at least one first hydrophilic surfactant that is a polysorbate or an ethoxylated castor oil, and at least one second hydrophilic surfactant that is an ethoxylated fatty alcohol, an ethoxylated fatty acid, or an ethoxylated glyceride of a fatty acid.

[0028] In some embodiments, the formulation comprises a total amount of at least about 8 wt% hydrophilic surfactant. According to other embodiments, the formulation comprises from about 8 wt% to about 25 wt% hydrophilic surfactant.

[0029] In some embodiments, the ratio between the at least one first hydrophilic surfactant and the at least one second hydrophilic surfactant is from about 1:2 to about 5:1 (w / w).

[0030] In some embodiments, the at least one first hydrophilic surfactant is present in the formulation in an amount ranging from about 8 to about 14 wt %, while the at least one second hydrophilic surfactant is present in an amount ranging from about 1 to about 6 wt %.

[0031] As mentioned above, the nano-domains comprise, in addition to the at least one hydrophilic surfactant, at least one alcohol and at least one polyol, where, in the context of the present disclosure, alcohol is intended to denote an organic compound having a hydroxyl functional group attached to a saturated carbon atom, and polyol is intended to denote an organic compound containing two or more hydroxyl groups.

[0032] The combination of at least one alcohol and at least one polyol cooperates with the hydrophilic surfactant to form a dense and complete interface, thereby stabilizing the interface between the nanodomains and the aqueous phase. The combination of hydrophilic surfactant, alcohols, and polyols provides favorable solubilization conditions for the gradual migration of the surfactant to the interface upon dilution with the aqueous phase. At low water contents, alcohols and polyols are essential components to induce lipophilic behavior of the hydrophilic surfactant, thereby adjusting its clinically effective packing parameter (ECPP) to greater than 1.3. At higher water levels (e.g., 40-50%), the alcohols and polyols "push" the surfactant toward the interface, causing a significant change in ECPP below 0.5. In other words, the alcohols and polyols control and adjust the hydrophilic / lipophilic nature of the surfactant to match the water content of the formulation. Thus, the combination of alcohols and polyols allows for complete geometric packing of the interface, filling the interfacial spaces between the surfactants. Without being limited to a particular theory, it is believed that after application to the nail / skin and evaporation of the water / volatiles, the nano-domains rearrange within the polymer matrix and the interstices are filled by the non-volatile components (glycerol, PG, PEG). During evaporation of the volatile components and film formation, the polyols act as hydrating agents for the nano-domains and / or form part of the continuous phase.

[0033] Furthermore, without being limited to a particular theory, it is believed that in the interfacial structure of the nano-domain, the alcohol is typically located deeper within the interface, and the interface that the nano-domain makes with the aqueous phase has a curvature elasticity (R e ) and spontaneous curvature elasticity (R s or R o The polyol is closer to the head groups of the surfactants, dehydrating them and facilitating the solubilization of the antifungal active agent within the droplets.

[0034] According to some embodiments, the at least one alcohol is selected from short chain aliphatic alcohols and aromatic alcohols, hi some embodiments, the at least one alcohol is selected from ethanol, propanol, isopropanol, butanol, benzyl alcohol, transcutol, and combinations thereof.

[0035] In some embodiments, the formulation comprises at least two alcohols.

[0036] In some embodiments, the formulation comprises a total amount of at least about 12 wt% alcohol, while in other embodiments, the formulation comprises between about 12 wt% and about 30 wt% alcohol.

[0037] According to some embodiments, the weight ratio between the total amount of hydrophilic surfactants and the total amount of alcohol in the formulation ranges from about 1:1 to about 1:3.

[0038] According to some embodiments, the at least one polyol is selected from propylene glycol, glycerol, xylitol, sorbitol, and other monomeric or dimeric sugar units, polyethylene glycol (PEG), 1,3-propanediol, butylene glycol (1,2-butanediol), pentylene glycol (1,2-pentanediol), 1,2-octanediol, and combinations thereof.

[0039] In some embodiments, the formulation comprises at least about 2 wt% total polyols, while in other embodiments, the formulation comprises from about 2 wt% to about 12 wt% polyols.

[0040] According to some embodiments, the weight ratio between the total amount of hydrophilic surfactants and the total amount of polyols in the formulation ranges from about 1:1 to about 5:1.

[0041] According to some other embodiments, the weight ratio between the total amount of alcohols and the total amount of polyols in the formulation ranges from about 1:1 to about 10:1.

[0042] In some embodiments, the nano-domains further comprise at least one solvent different from the at least one alcohol. The solvent typically functions to enhance solubilization of the antifungal active agent within the nano-domains, thereby increasing the maximum concentration of the antifungal active agent that can be stably incorporated within the nano-domains. In some embodiments, the at least one solvent is selected from transcutol, dimethyl sulfoxide (DMSO), ethanol, dimethylformamide (DMF), tetrahydrofuran (THF), dimethylacetamide (DMA), N-methyl-2-pyrrolidone (NMP), amines, and combinations thereof. In other embodiments, the at least one solvent is selected from transcutol, dimethyl sulfoxide (DMSO), ethanol, and combinations thereof.

[0043] In some embodiments, the total amount of solvent in the formulation is up to 16 wt%, typically in the range of about 3 wt% to about 10 wt%.

[0044] As noted above, the aqueous continuous phase of the formulation comprises water, at least one film-forming agent in an amount of about 1% or less by weight of the formulation, and at least one keratolytic agent.

[0045] The keratolytic agent is a compound that causes softening and / or at least partial disintegration of stratum corneum, facilitating improved penetration of the nano-domains and / or the antifungal active agent contained therein into the stratum corneum. According to some embodiments, the keratolytic agent is selected from glycerol, urea, lactic acid, dimethyl sulfoxide (DMSO), dimethicone, an alpha hydroxy acid (such as salicylic acid), or any combination thereof.

[0046] In some embodiments, the total amount of keratolytic agent in the formulation is up to 15 wt%, for example, in the range of about 5 wt% to about 14 wt%.

[0047] As mentioned above, the total amount of water in the formulation ranges from about 35 wt% to about 55 wt%. The water content significantly affects the viscosity and structure of the formulation. Higher water contents significantly reduce the viscosity of the formulation, shortening the contact time between the formulation and the keratinous tissue and preventing the formulation from adhering to the keratinous tissue. Low water contents inhibit the spontaneous formation of nanodomains within the aqueous phase; this is because the relatively high amounts of film-forming agents and keratolytic agents at low water contents prevent the hydrophilic surfactants, alcohols, and polyols from stably and spontaneously arranging the nanostructures. Furthermore, lower water contents will cause a rapid increase in the viscosity of the aqueous phase, impairing the spreadability of the formulation on the tissue.

[0048] The aqueous phase contains at least one film-forming agent. The film-forming agent is a compound that increases the viscosity of the aqueous phase to a desired viscosity, and when applied to keratinous tissue, the volatile components evaporate from the formulation after application to form a thin film. The film-forming agent typically forms a three-dimensional network of polymers (e.g., a viscoelastic network of polymer chains) in which nano-domains are embedded and uniformly dispersed, thereby increasing the viscosity and adjusting the rheological behavior of the aqueous phase.

[0049] The formulations of the present disclosure are formulated so that when applied to keratinous tissue, the formulation forms a film on the keratinous tissue with the nano-domains embedded therein.In other words, the formulations contain at least 10 wt% of volatile components that can evaporate when the formulation is applied to keratinous tissue, but the components allow the remaining components of the formulation present on the tissue to form a film that adheres to the keratinous tissue for a long time, from which the nano-domains and the antifungal active agent can be released into the keratinous tissue.The term volatile component is intended to refer to a compound other than water that can evaporate significantly at atmospheric pressure and at a temperature of at least about 30°C.

[0050] In some embodiments, the at least one film-forming agent is selected from water-soluble or colloidal water-soluble polymers (hydrocolloids); such water-soluble or colloidal water-soluble polymers include cellulose ethers (e.g., hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methylcellulose), polyvinyl alcohol, polyquaternium-10, guar gum, hydroxypropyl guar gum, xanthan gum (Keltrals, Xanturals (e.g., Xantural 11K, Xantural 180K, Xantural 75, etc.)), gellans (Kelogels), gelatin and gelatin derivatives, aloe gel (Aloe vera gel), and the like. gel), amla, carrageenan, oat flour, starch and modified starches (derived from corn, rice, or other plants), gelatin (derived from pig or fish skin), ghatti gum, gum arabic, inulin (derived from chicory), konjac gum, locust bean gum (LBG), fenugreek, marshmallow root, pectin (high and low methoxy) and modified pectins, quinoa extract, red algae, sola gum, tragacanth gum (TG), and any mixtures thereof.

[0051] In some other embodiments, the film-forming agent is selected from acrylic acid / ethyl acrylate copolymers and the Carbopol resins, a class of registered trademark carboxyvinyl polymers. Examples include Carbopol 934, Carbopol 940, Carbopol 950, Carbopol 980, Carbopol 951, and Carbopol 981. Carbopol 934 is a water-soluble polymer of acrylic acid crosslinked with a polyallyl ether of sucrose, containing an average of about 5.8 allyl groups per sucrose molecule. Hydrophobically modified crosslinked acrylic acid polymers with amphiphilic properties are also suitable and are available under the trade names Carbopol 1382, Carbopol 1342, and Pemulen TR-1. Combinations of polyalkenyl polyether crosslinked acrylic acid polymers and hydrophobically modified crosslinked acrylic acid polymers may also be suitable.

[0052] According to some embodiments, the film-forming agent is selected from xanthan gum, gellan, sodium alginate, pectin, low and high methoxy pectins, carbomers, and mixtures thereof.

[0053] According to another embodiment, the film-forming agent is xanthan gum or gellan.

[0054] According to some embodiments, the formulation comprises up to about 0.5 wt% of the at least one film-forming agent, hi some embodiments, the formulation comprises from about 0.05 wt% to about 0.5 wt% of the at least one film-forming agent.

[0055] In some embodiments, the film formed on the keratinous tissue after application of the formulation is substantially transparent.

[0056] In some other embodiments, the film formed on the keratinous tissue after application of the formulation comprises about 2 wt% or less of a film-forming agent.

[0057] According to another aspect of the present disclosure, there is provided a formulation for forming a depot of an antifungal active agent on keratinous tissue, the formulation comprising nano-domains dispersed in an aqueous continuous phase. The nano-domains comprise the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol. The aqueous phase comprises water, at least one film-forming agent in an amount of about 1 wt% or less, and at least one keratolytic agent, the total amount of water in the formulation being about 35 wt% to about 55 wt%. The formulation is formulated to form a film containing the nano-domains embedded therein when applied to keratinous tissue, the film having a residence time on the keratinous tissue of about 1 hour to 24 hours.

[0058] In other words, the formulation is designed to form a film with properties that allow it to remain on the keratinous tissue for a certain period of time when applied to the keratinous tissue, with the aim of forming reservoirs of nano-domains on the tissue that allow for increased contact time and increased amounts of antifungal active agent delivered to the keratinous tissue during contact.

[0059] In another aspect, a formulation for topical delivery of an antifungal active agent to keratinous tissue is provided, the formulation comprising nano-domains dispersed in an aqueous continuous phase; the nano-domains comprising the antifungal active agent, at least one hydrophilic surfactant, at least one co-surfactant, and optionally at least one solvent; the aqueous phase comprising water, at least one film-forming agent in an amount of about 1 wt% or less, at least one keratolytic agent, and at least one solvent; and the total amount of water in the formulation is about 35 wt% to about 55 wt%.

[0060] As mentioned above, the formulation is designed so that when the components of nano-domains are introduced into the aqueous phase, the spontaneous formation of nano-domains occurs.Therefore, the components of the formulation can be kept separately, and the formulation can be prepared shortly before use.Therefore, in another aspect, the present disclosure provides a kit for preparing the formulation that delivers antifungal active agent to keratinous tissue, the kit comprises: a first container holding a concentrate comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol; a second container holding an aqueous solution comprising water, at least one film-forming agent and at least one keratolytic agent in an amount of about 1 wt% or less based on the total weight of the formulation; and mixing said concentrate with said aqueous solution to obtain a topical formulation in the form of nano-domains dispersed in an aqueous continuous phase; Includes; Here, the kit is configured so that the concentrate and the aqueous solution are mixed together so that the total amount of water in the formulation is about 35 wt % to about 55 wt %.

[0061] In other words, prior to application, the concentrate (comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol) can be kept separate from the aqueous solution; and the kit is configured to allow mixing of the concentrate and the aqueous solution in the field to obtain a formulation having a structure of nano-domains dispersed in an aqueous continuous phase.

[0062] A mixing means may be used, such as a mechanically or electrically operated mixer, or mixing may be performed by one or more static mixers, i.e., a mechanical structure that allows the concentrate and the aqueous solution to be simultaneously introduced to a site under forced flow through a static mixing mechanism (e.g., a stationary baffle or flow divider), which results in good mixing of the concentrate and the aqueous solution without the need for high shear forces to achieve the formulation.

[0063] By controlling the amounts of concentrate and aqueous solution introduced into the mixing means, the final water content of the prepared formulation can be controlled.

[0064] For example, the kit may include containing and holding first and second containers and may be configured to position a mixing structure adjacent to an application means in a container, which may further include one or more dispensing means that allow for controlled dispensing of the concentrate and the aqueous solution into the mixing structure to ensure the appropriate final water content in the formulation.

[0065] In another aspect, there is provided an applicator for topically applying a formulation as described herein to keratinous tissue, the applicator comprising at least one compartment for holding the formulation and means for applying the formulation to keratinous tissue.

[0066] In yet another aspect, there is provided an applicator for topically applying a formulation as described herein to keratinous tissue, the applicator comprising: a first container holding a concentrate comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol; a second container holding an aqueous solution comprising water, at least one film-forming agent in an amount of about 1 wt% or less based on the total weight of the formulation, and at least one keratolytic agent; mixing said concentrate with said aqueous solution to obtain said formulation in the form of nano-domains dispersed in an aqueous continuous phase; and a means for applying the preparation to keratinous tissue; The applicator is configured to mix the concentrate and the aqueous solution so that the total amount of water in the formulation is about 35 wt % to about 55 wt %.

[0067] In a further aspect of the present disclosure, there is provided a method of delivering an antifungal active agent to keratinous tissue, comprising topically applying to the keratinous tissue a formulation as described herein.

[0068] In a further aspect, there is provided a method of treating a fungal infection of keratinous tissue, comprising topically applying to keratinous tissue a formulation as described herein.

[0069] As used herein, "treatment" or any grammatical variation thereof refers to administering a therapeutic amount of a formulation described herein, which formulation is effective for: Ameliorating undesirable symptoms associated with a fungal infection, preventing the onset of symptoms before such symptoms occur, slowing the progression of a fungal infection, slowing the worsening of symptoms, promoting the onset of remission, slowing irreversible damage caused by advanced stages of a fungal infection, delaying the onset of said advanced stages, reducing the severity of or curing a fungal infection, or preventing recurrence of the infection, or a combination of two or more of the above.

[0070] As is known, the effective amount for the purpose of this specification can be determined by the knowledge known in the art.Effective amount is typically determined in a well-designed clinical trial (dose range test), and those skilled in the art will know how to properly carry out such a test to determine the effective amount.As is known, effective amount depends on various factors, such as distribution profile in the body, various pharmacological parameters, undesirable side effects (if any), age and sex and so on.

[0071] According to some embodiments, the formulations can be used to treat conditions associated with dermatophytes and non-dermatophyte fungi, including: Tinea unguium, Trichophyton rubrum, Trichophton mentagrophytes, Trichophyton interdigitale, Trichophyton tonsurans, Trichophyton violaceum, Trichophyton schoenleinii, Trichophyton megninii, Trichophyton soudanense, Trichophyton yaoundei, Microsporum audouinii, Microsporum ferrugineum, Nannizzia gypsea, Epidermophyton floccosum, Candida albicans, Fusarium species, Aspergillus, Acremonium species, Scytalidium species, Scopulariopsis brevicaulis, Microsporum canis, Trichophyton equinum, Trichophyton erinaceid, Trichophyton verrucosum, Microsporum nanum, Microsporum distortum, Microsporum gypseum, Sporothrix schenckii, Malassezia furfur, and Onychocola canadensis.

[0072] According to another aspect, there is provided a method of treating Tinea unguium infection of keratinous tissue, comprising topically applying to the keratinous tissue a formulation as described herein.

[0073] In another aspect, there is provided a formulation as described herein for use in treating a fungal infection of keratinous tissue.

[0074] In yet another aspect, there is provided a formulation as described herein for use in treating Tinea unguium infection of keratinous tissue.

[0075] The phrases "ranging / ranges between" a first denoted number and a second denoted number and "ranging from a first denoted number to a second denoted number" are used herein as synonyms and are intended to include the first denoted number and the second denoted number, as well as all fractional and integer values ​​within that range. It should be noted that when various embodiments are described using a given range, the range is used merely for convenience and brevity and should not be considered an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to include all possible subranges specifically disclosed, as well as all individual numerical values ​​within that range.

[0076] As used herein, the term "about" is intended to include a variation of ±10% relative to the value of the parameter (temperature, pressure, concentration, etc.) specifically mentioned.

[0077] Unless the context clearly indicates otherwise, the above terms "comprise", and variations such as "comprises" and "comprising", are to be understood as meaning the inclusion of the stated integer or step or group of integers or steps, and not the exclusion of any integer or step or group of integers or steps.

[0078] It should be noted that, in general, the phrase "at least one" when used with respect to any component of a formulation disclosed herein should be interpreted to include one, two, three, four, or more of the components in the formulation.

[0079] It should be understood that certain features of the present disclosure, which are described for clarity in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present disclosure that are described for brevity in the context of a single embodiment may also be provided individually or in any suitable subcombination, or as suitable for any other embodiment described in the present disclosure. Certain features described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment would be ineffective without those elements.

[0080] For the purpose of making the subject matter of the present disclosure better understood and illustrating how it may be carried into practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0081] [Figure 1] 1 is a photograph of an exemplary composition of the present disclosure. [Figure 2] Figures 2A-2I. Permeation profiles obtained by LUMiSizer® for several formulations: AP950 (Figure 2A), AP_05 (Figure 2B), MUR_5A (Figure 2C), MUR_5B (Figure 2D), MUR_5C (Figure 2E), AP4500 (Figure 2F), AP4500LX (Figure 2G), NK003 (Figure 2H), and REAP4500 (Figure 2I). [Figure 3]Figures 3A-3I show droplet size distributions obtained by DLS measurements for several formulations: AP950 (Figure 3A), AP_05 (Figure 3B), MUR_5A (Figure 3C), MUR_5B (Figure 3D), MUR_5C (Figure 3E), AP4500 (Figure 3F), AP4500LX (Figure 3G), NK003 (Figure 3H), and REAP4500 (Figure 3I). [Figure 4] Figures 4A-4D show cryo-TEM images for the following formulations: MUR_05 (Figure 4A), MUR_5C (Figure 4B), AP4500 (Figure 4C), and AP4500LX (Figure 4D). Arrows indicate free water crystallization. [Figure 5] Figures 5A-5G show the viscosity as a function of shear rate for some of the formulations: AP950 (Figure 3A), AP_05 (Figure 3B), MUR_5A (Figure 3C), MUR_5B (Figure 3D), MUR_5C (Figure 3E), AP4500 (Figure 3F), and AP4500LX (Figure 3G). [Figure 6] Figures 6A-6F show the appearance of empty and TRB-containing AP950 formulations after storage at 25°C for up to 9 months and at 40°C for up to 6 months. 2.4% TRB at 25°C (Figure 6A); 2.4% TRB at 40°C (Figure 6B); empty vehicle at 25°C (Figure 6C); empty vehicle at 40°C (Figure 6D); 2.4% TRB in a pen applicator at 25°C (Figure 6E); and 2.4% TRB in a pen applicator at 40°C (Figure 6F). [Figure 7] Photographs of nails prepared for penetration testing: Area "a" - the area where the sample is in contact with the nail; and area "b" - the adjacent area where the sample is not in contact with the nail. [Figure 8] 8A-8E. Average total nail involvement (FIG. 8A) and the percentage of subjects with total nail involvement at 0, 6, 12, and 16-24 weeks (FIGS. 8B-8E, respectively) during the course of treatment for subjects treated with a test formulation according to the present disclosure of 2.4% terbinafine hydrochloride in a Phase I / IIa clinical trial. [Figure 9] 1 shows the average nail thickness measured in subjects treated with the test formulation in a Phase I / IIa clinical trial. [Figure 10]1 shows the mean percentage of total nail involvement as a function of time in subjects treated with the test formulation in a Phase I / IIa clinical trial. [Figure 11] The complete cure rate with the test formulation is shown in comparison with several commercially available products. DETAILED DESCRIPTION OF THE INVENTION

[0082] Exemplary Compositions Exemplary formulations according to the present disclosure are shown in Tables 1-1 and 1-3. These formulations were prepared according to the following protocol: A concentrated solution was prepared by mixing the surfactant, co-surfactant / solvent, and penetration enhancer at room temperature or slightly elevated temperature (e.g., 40-60°C) to obtain a homogeneous solution. Terbinafine hydrochloride (TRB) was then added. TRB was selected as a model molecule to demonstrate the ability of the composition to deliver an antifungal agent to the nail area.

[0083] An aqueous phase was prepared separately by first dissolving the film-forming polymer and then adding the keratolytic agent. Finally, the pH was adjusted to approximately 3.8-4.2 by adding one or more organic bases. This concentrate was then mixed with the aqueous phase at room temperature to obtain the final nanostructures.

[0084] [Table 1]

[0085] [Table 2]

[0086] [Table 3]

[0087] The compositions were characterized to assess their physical properties, chemical stability under various conditions, and performance, as detailed below.

[0088] Physical characterization All of the tested formulations exhibited a nanostructure of surfactant-based nanodomains uniformly dispersed in the aqueous phase. As can be seen in Figure 1, these formulations exhibited high transparency, a high degree of uniformity, and thermodynamic stability.

[0089] LUMiSizer® Testing The physical stability of the formulations was evaluated by Lumicizer®, an analytical centrifuge that monitors the light transmitted through a sample as it is centrifuged horizontally. Changes in transmission indicate sample stability; if the transmission profile remains constant, the sample is considered physically stable and its shelf life can be estimated based on the measurement conditions. Under the measurement conditions used, the estimated shelf life is at least two years.

[0090] The permeation profiles (% permeation as a function of measurement location and time) for some of the formulations are shown in Figures 2A-2I. As clearly shown, no change in permeation was observed (i.e., complete permeation was observed) for all formulations tested; this indicates that all formulations are stable and are expected to remain stable for at least 2 years from preparation.

[0091] Droplet size After dilution with water, the above system was further characterized by dynamic light scattering (DLS) and cryo-TEM (the sample was measured without further processing) to confirm the presence of nanostructures. Figures 3A-3I show the droplet size distribution (measured as the volume fraction of droplets). A summary of the analysis results by DLS is shown in Table 2.

[0092] [Table 4]

[0093] As can be seen from Table 2 and Figures 3A-3I, all of the compositions tested consisted of nanodroplets of approximately 8-10 nm, which accounted for over 98% of the total droplets.

[0094] Figures 4A-4D show cryo-TEM images confirming the presence of nanodomains. As the images show, the formulations in both 2.4% TRB and 5.0% TRB consist of nanostructures smaller than approximately 10 nm. Due to the high density of the structures and the limited contrast between the structures and the water in the continuous phase, the morphology and size of the nanostructures can only be roughly assessed. The arrows in the images indicate free water crystallization, but this often occurs and is related to the sample preparation rather than the actual structure.

[0095] viscosity As mentioned above, formulations of the present disclosure must exhibit a low enough viscosity to allow easy application, yet be thick enough to provide adhesion that allows adequate contact with the nail plate. Figures 5A-5G show the viscosity as a function of shear rate for some of the formulations; Table 3 shows the apparent viscosity values.

[0096] The viscosity measurements were performed using an RS6000 flowmeter (Thermo Scientific) equipped with a C60 / 1 TiL-L12007 cone. The instrument was operated at shear rates of 0.00010 to 50.00 s -1 The viscosity was measured in rotational mode within a range of 100° C. for 6 minutes. All measurements were performed at 25±1° C. Under these conditions, the formulations have non-Newtonian behavior, so the viscosity was reported for the lowest shear rate observed.

[0097] [Table 5]

[0098] The viscosity profiles show behavior typical of pseudoplastic, non-Newtonian fluids (viscosity decreasing with increasing shear rate). Overall, the measured viscosities at low shear varied between 3.0 and 4.5 Pa·s, with the exception of AP4500LX, whose viscosity was slightly lower due to the lower concentration of xanthan gum (0.15% compared to 0.2% for all other components).

[0099] Structural analysis by PGSE-NMR The fluidity of the above formulation components was also measured by PGSE-NMR. The diffusion coefficients (×10 -11 ) are shown in Table 4. The measurements were performed under a gradient / pulse program with δ = 15.0 ms, Δ = 200.0, and gmax = 40.40. Diffusion coefficients were calculated using Dynamic Center software from fitting functions plotted individually for each signal. The reported diffusion coefficients are the average values ​​calculated for the corresponding peaks of each component.

[0100] The surfactant diffusion coefficients are shown as average values ​​for all three surfactants used (Brij CS20, Tween 20, and Tween 60), while the co-surfactant diffusion coefficients are average values ​​calculated for propylene glycol, ethanol, isopropanol, transcutol, glycerol, and PEG400.

[0101] [Table 6]

[0102] As can be seen from Table 4, PGSE-NMR measurements were used to evaluate the diffusivity of surfactants, co-surfactants, benzyl alcohol, urea, lactic acid, DMSO, TRB, and water. Overall, there were no significant differences in the diffusivity of any of the components among all the tested samples, with the only exception being MUR_05C, which consistently showed lower D values ​​(i.e., lower diffusivity) due to its lower water content (40.8% for MUR_05C compared to 45.8% for all other systems). Across all samples, surfactants showed the lowest diffusivity (0.6–1.0 × 10 -11 m 2 / s).

[0103] In addition to TRB, the diffusion coefficients for all other components are 10 -10 m 2 / s, with urea and water showing the fastest mobility. TRB molecules were found to be more diffusive than surfactants (4.1–5.7 × 10 -11 m 2 / s), suggesting that TRB is likely located in the outer layer at the interface between the surfactant molecules and the aqueous phase. The formulation containing 5% TRB had a lower measured diffusivity (i.e., 5.7 × 10) compared to AP950 containing 2.4% TRB. -11 m 2 / s compared to 4.1~4.6×10 -11 m 2 / s), which was noteworthy, as it indicated that at higher TRB levels, TRB tended to bind to the detergent.

[0104] Compared to urea and cosurfactants, lactic acid molecules appear to diffuse slightly slower. This may suggest that lactic acid molecules partially interact with other components (presumably TRB) and contribute to their ionization. The absence of urea and lactic acid in composition MUR_05B does not appear to significantly affect the diffusivity of any of the other components.

[0105] Additives such as lactic acid and urea, which act as keratolytic agents, contribute significantly to the potential efficacy of the formulation for treating onychomycosis. As shown by NMR measurements, the diffusivities of both components are relatively high, suggesting that they are located (fully or partially) in the continuous phase. Therefore, both components can interact with the nail plate and enhance TRB penetration into the nail.

[0106] The benzyl alcohol molecule exhibits slightly lower diffusivity compared to the other cosurfactants, possibly due to the hydrophobic nature of the benzyl alcohol molecule (15.3–17.7 × 10 -11 m 2 / s), it is therefore likely that this molecule solvates the interface, possibly helping to stabilize it in the presence of TRB.

[0107] chemical stability Selected formulations, AP950, were tested for TRB chemical stability under standard conditions (25°C) and accelerated conditions (40°C). Vehicle (AP950 without TRB) was also tested as a control. Appearance, pH, TRB assay, and impurity formation were evaluated as part of the stability study. In this study, the TRB-containing compositions were packaged in two different packages: glass vials and pen-type applicators. Figures 6A-6F show the appearance of empty and TRB-containing AP950 formulations after storage at 25°C for up to 9 months and at 40°C for up to 6 months.

[0108] As can be seen from Figures 6A to 6F, AP950 (containing TRB) showed very little coloring after 9 months of storage at 25°C. Samples packed into pen-type applicators showed no coloring after storage at either 25°C or 40°C.

[0109] All samples were also tested for pH. Tables 5-1 and 5-2 summarize the pH values ​​obtained for both loaded and empty AP950 at 25°C and 40°C.

[0110] [Table 7]

[0111] [Table 8]

[0112] For both the empty and TRB-containing systems, the pH decreased upon storage at both 25°C and 40°C, with changes in pH values ​​of approximately -0.2 and up to -0.1 observed after 9 months of storage at 25°C and 6 months at 40°C, respectively. No significant differences were observed between the TRB-containing systems and the vehicle, and between the different packages.

[0113] Tables 6-1 and 6-2 provide a summary of the assay results (as % of the labeled amount) for AP950 stored at 25°C and 40°C in both glass vials and pen applicators.

[0114] [Table 9]

[0115] [Table 10]

[0116] As shown in Tables 6-1 and 6-2, TRB levels remain stable at both 25°C and 40°C when the formulation is stored in glass vials. A slight decrease was detected (within the error of measurement) at 25°C. Overall, the AP950 formulation is stable upon storage under accelerated and standard conditions.

[0117] Impurity levels were also monitored as part of the stability studies, and impurity levels (%) are shown in Tables 7-1 and 7-2.

[0118] [Table 11]

[0119] [Table 12]

[0120] Upon storage at 25°C and 40°C, impurity levels gradually increase, reaching values ​​of up to 0.8% at 40°C and 0.5% at 25°C. Despite such increases, detection levels are within the limits usually specified by regulatory authorities (NMT 1% for unknown impurities and NMT 2% for total impurities). No significant changes in impurity levels were observed (within measurement error) between the two packaging types.

[0121] Performance Test To evaluate the performance of the formulations in delivering active compounds to skin and nail tissue, a series of experiments were performed using Franz cells, where the target membrane was either porcine skin (harvested from pig ears) or human toenail.

[0122] Skin penetration test The test was carried out using the following protocol: A 5 mL receiving chamber was filled with phosphate buffer (pH 7.6). 2 A skin piece was placed in the receptor chamber opening (9 mm in diameter), and the donor compartment was fixed on top of the skin. Approximately 85 mg of formulation sample was placed in the donor compartment and placed in direct contact with the skin. The system was sealed and set to a controlled temperature of 32 ± 2°C for 24 hours. After gently washing away the remaining sample (referred to as "skin"), the receptor chamber liquid (referred to as "RC") and the skin piece were collected. TRB levels in each layer (RC and skin) were measured by HPLC.

[0123] The penetration results from multiple independent tests in mg of TRB per surface area and percent application are shown in Table 8.

[0124] [Table 13]

[0125] The prototypes containing 2.4 wt% TRB showed average TRB penetration levels of approximately 6.8-13.3% and 1.9-4.3% in the skin and RC, respectively. Of all the prototypes containing 2.4 wt% TRB, prototype AP4500 showed the highest TRB penetration levels in both the skin and RC.

[0126] The absolute TRB penetration rate for the 5.0% TRB system was higher than that at the lower concentration (2.4%), reaching 0.24 mg / cm in the skin. 2 Compared to approximately 0.43 to 0.81 mg / cm 2 and 0.07 mg / cm for RC. 2 compared to 0.02-0.09 mg / cm 2 The accumulation of TRB in the skin was significantly greater at higher TRB concentrations than at lower TRB contents. However, the effect of TRB concentration on penetration in RC appears to be much less. Similar results were observed for the 2.4% and 5.0% TRB systems in terms of the percent penetration (relative to the applied dose), with the exception of MUR_5B, which showed superior TRB penetration into the skin.

[0127] Nail penetration test The test was performed according to the following protocol. A system was constructed as described in the skin penetration test above, except that the nail / hoof was placed in a dedicated adapter. Approximately 85 mg of the test composition sample was placed in the donor compartment and placed in direct contact with the nail / hoof. The system was operated for 7 days, and every 24 hours the nail / hoof was washed with water and another 85 mg of sample was applied to the same area. At the end of the 7th day, each nail / hoof was removed and washed with distilled water.

[0128] Two locations on the nail / hoof were drilled using a Dremel 3000: site a, where the sample contacted the nail / hoof; site b, an adjacent site where the sample did not contact the nail / hoof (as shown in Figure 7). Approximately 4.0 mg of the drilled nail / hoof sample was accurately weighed. TRB levels in the nail / hoof were analyzed by HPLC.

[0129] Table 9 shows the cumulative permeation levels of TRB for the AP950 system compared to the commercially available Lamisil® Once in terms of penetrating TRB per toenail (μg TRB / mg TN) over 7 days of continuous exposure.

[0130] [Table 14]

[0131] As shown in Table 9, the cumulative penetration of TRB administered with AP950 was 2-6 times higher (depending on the site examined) compared to Lamisil® Once. Overall, the results demonstrate that the AP950 formulation can enhance TRB penetration into the nail plate in both vertical and horizontal directions, better than the commercial products.

[0132] The measured mean, minimum and maximum values ​​obtained from the above experiments were further used to evaluate TRB exposure after one week of treatment with the original AP950 containing 2.4 wt% TRB-HCl.

[0133] The following data were used in the exposure calculation: contact area, 6.165 mm 2 ;Applied sample, 4.0 mg;Minimum nail size, 234.5 mm 2 Maximum claw size: 441.8mm 2 A rectangular morphology was assumed for nail size calculations. Toenail length was determined according to Johnson and Shuster [7]; the minimum and maximum lengths reported in this reference were 14.6 mm and 18.8 mm, respectively. Toenail width was assumed to vary with toenail length; i.e., W min =1.1L min and W max =1.25L max .

[0134] Table 10 summarizes the TRB-HCl exposure assessment for one week of daily use (once daily) of the AP950 system containing 2.4 wt% TRB.

[0135] [Table 15]

[0136] As shown in Table 10, exposure to TRB is estimated to be in the range of approximately 30–390 μg depending on toenail size. MICs of TRB ranged from 0.03–0.5 μg / mL for both Trichophyton rubrum and Trichophyton mentagrophytes [8, 9]. 50 Based on the results presented herein, the estimated TRB exposure achieved by application of AP950 reaches the level required to achieve effective treatment.

[0137] In further experiments, TRB penetration into the hoof membrane was investigated. The hoof, being a keratinized tissue, can be used as a surrogate model for the nail. Formulation AP4500 was tested for TRB penetration into horse hooves. The results are shown in Table 11 in μg TRB / mg HOOF. Note that drilling was performed in the application area (referred to as Site A) where the sample contacted the hoof.

[0138] [Table 16]

[0139] As can be seen, the cumulative penetration of TRB into the hoof as well as the nail penetration (when formulated in AP950) was 1.56 μg / mg after 7 days.

[0140] Phase I / IIA clinical trial for the treatment of onychomycosis Onychomycosis (tinea unguium) is a common chronic fungal nail infection that can cause nail discoloration, thickening, and separation from the underlying nail bed. Toenails are more susceptible to infection due to slower nail growth, lack of an effective source of immune cells, a higher likelihood of repeated cycles of reinfection, and an ideal environment for fungal growth (e.g., dark and moist). Onychomycosis can also affect quality of life, as its physical appearance can cause anxiety, distress, embarrassment, low self-esteem, and social withdrawal. Onychomycosis is divided into several classes; the major class is distal marginal subungual mycosis (DLSO), which is the most common and was therefore selected as the disease to treat.

[0141] Test Protocol This is a Phase I / IIa, open-label, single-center pilot study; evaluating, first, the safety and, second, the efficacy of the test formulation of the present disclosure (2.4 wt% terbinafine hydrochloride) administered topically twice daily via a pen applicator; in treating patients with mild to moderate onychomycosis (fungal infection of the big toe nail).

[0142] Subjects who entered the study received the test formulation for a period of 16 to 24 weeks as their full treatment; during this period, the product was applied twice daily (morning and evening) to the targeted great toenail (TGT) and surrounding skin after cleaning and drying the treatment area. Subjects were monitored for adverse events (AEs), serious adverse events (SAEs), and / or local tolerability reactions (LTRs). Additionally, TGT onychomycosis was assessed (as the percentage of infected nails) and the number of millimeters of healthy nail growth was measured. Affected nails were marked with a permanent marker pen and photographed to monitor and evaluate healthy nail growth. At week 16, subjects were assessed for onychomycosis status. If the healthy nail was 4 mm or greater, they were considered to have completed treatment (EOT); if the healthy, clear nail was less than 4 mm, they were asked whether they would like to continue treatment for another 8 weeks. At both the baseline visit (before treatment began) and the end of treatment (EOT) visit, TGT samples were taken using a scalpel and sent to the microbiology laboratory for KOH wet embedding microscopic examination to determine the presence or absence of fungi and for placement on specialized plates for culture to determine the type of fungus.

[0143] Safety Results The majority of subjects (67%) completed treatment after 16 weeks, and a minority of subjects (33%) continued treatment through week 24. Furthermore, the dropout rate was relatively low (12%), indicating that the treatment was relatively easy to administer.

[0144] No adverse effects were reported as a result of treatment. Thus, the test product was found to be well tolerated and safe for topical use. No local tolerability reactions, related or unrelated adverse events or reactions, or severe adverse events or reactions were recorded in any subject during the course of the study.

[0145] Clinical efficacy results Three independent studies were conducted to determine the efficacy rate of test drugs for treating onychomycosis; the studies included: (1) Change in measured lesion-free area, calculated as delta values ​​for healthy nails at the end of the study and compared with values ​​measured at baseline treatment [EOT-Baseline = ΔHealthy Nail (in mm )]; (2) KOH microscopic test (negative / positive); and (3) Culture (negative / positive).

[0146] All subjects tested were found to be KOH-negative and their cultures negative (no fungal growth). The mean healthy nail size for all subjects increased from 5 (±1.41) mm measured at baseline to 10 (±4.54) mm at the end of treatment. The majority of subjects measured a visible increase in clear / healthy nails (≥4 mm of healthy nail growth) compared to baseline, indicating a clinical success rate of 76.2%; details are shown in Tables 12-1 and 12-2 and Figures 8A-8E.

[0147] [Table 17]

[0148] [Table 18]

[0149] [Table 19]

[0150] Clinical Efficacy Results Efficacy estimates include: (1) Nail involvement in ≥10% of TGT (%); (2) KOH negative; and (3) Culture negative.

[0151] Targeting the three parameters listed above, the clinical efficacy rate based on all subjects tested was approximately 22%. In general, a visible reduction in the mean percentage of total infected nails was found to be 55% compared to baseline and 25% compared to follow-up visits (details shown in Figure 10 and Tables 13-1 and 13-2).

[0152] [Table 20]

[0153] [Table 21]

[0154] Complete cure Complete healing is defined as 0% infected nail (completely healthy nail) and KOH- and culture-negative. Three of the 18 subjects tested were found to have complete healing (approximately 22%).

[0155] Nail thickness and shape Normal nail thickness ranges from 1.0 to 1.5 mm. Nail thickness was assessed during the study because it is known to be associated with onychomycosis. Nail thickness typically increases when the nail becomes infected and decreases as it heals.

[0156] The average nail thickness of all subjects tested decreased over the course of the study (Figure 9); this indicates that the nails returned to normal thickness and healthy nails.

[0157] All infected nails were dark to brown in color, with the majority of toenails having "broken edges." In all cases with a minimum of 4 mm of growth, the infected nail changed from yellow and opaque to smooth and less yellow, or completely clear and crisp in appearance.

[0158] Comparison with commercially available products The complete cure rates for the test formulations at 16 or 24 weeks were compared to the complete cure rates after 12 weeks of treatment with the following products: Jublia® (efinaconazole), Hexima™ (pezadeftide), Kerydin™ (tavaborole), and MOB-015 (a terbinafine formulation developed by Mobera Pharma). As can be seen from Figure 11, the complete cure rate of the test formulations was significantly higher.

Claims

1. A formulation for topical delivery of an antifungal active agent to keratinous tissue, the formulation comprising nano-domains dispersed in an aqueous continuous phase; the nano-domains comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol; the aqueous phase comprises water, at least one film-forming agent in an amount of about 1 wt % or less, and at least one keratolytic agent; the total amount of water in the formulation is about 35 wt% to about 55 wt%; formulation.

2. 10. The formulation of claim 1, wherein the formulation is formulated such that upon application to the keratinous tissue, the formulation forms a film having embedded therein the nano-domains.

3. 3. The formulation of claim 2, wherein the film is substantially transparent.

4. 4. The formulation of claim 2 or 3, wherein the film comprises about 2 wt% or less of a film-forming agent.

5. 5. The formulation of any one of claims 1 to 4, comprising at least one oil in an amount of up to about 1 wt%.

6. A formulation according to any one of claims 1 to 5, which is devoid of oil.

7. 7. The formulation of any one of claims 1 to 6, wherein the formulation comprises at least 8 wt% total hydrophilic surfactant.

8. 8. The formulation of claim 7, wherein the formulation comprises about 8 wt% to about 25 wt% of a hydrophilic surfactant.

9. 9. The formulation of any one of claims 1 to 8, wherein the at least one hydrophilic surfactant is selected from ethoxylated fatty alcohols (cetosteareths, ceteths, oleths, steareths), polysorbates (Polysorbate 20, 60, 80), ethoxylated fatty acids (ethoxylated stearates), ethoxylated (hydrogenated / non-hydrogenated) castor oil, ethoxylated glycerides of fatty acids, PEGylated octylphenyl ethers, sugar esters, polyglycerol esters, copolymers of PEG, EO and PG moieties, lysolecithins, and combinations thereof.

10. The formulation according to any one of claims 1 to 9, comprising at least two hydrophilic surfactants.

11. The formulation according to any one of claims 1 to 10, at least one first hydrophilic surfactant which is a polysorbate or an ethoxylated castor oil; and at least one second hydrophilic surfactant which is an ethoxylated fatty alcohol, an ethoxylated fatty acid, or an ethoxylated glyceride of a fatty acid; 1. A formulation comprising:

12. 12. The formulation of any one of claims 1 to 11, wherein the formulation comprises a total of at least about 12 wt% alcohols.

13. 13. The formulation of claim 12, wherein the formulation comprises about 12 wt% to about 30 wt% alcohols.

14. 14. The formulation of any one of claims 1 to 13, wherein the at least one alcohol is selected from ethanol, propanol, isopropanol, butanol, benzyl alcohol, and combinations thereof.

15. A formulation according to any one of claims 1 to 14, comprising at least two alcohols.

16. 16. The formulation according to any one of claims 1 to 15, wherein the weight ratio between the total amount of hydrophilic surfactants and the total amount of alcohol in the formulation ranges from about 1:1 to about 1:

3.

17. 17. The formulation of any one of claims 1 to 16, wherein the at least one film-forming agent is present in the formulation in an amount ranging from about 0.05 wt% to about 0.5 wt%.

18. 18. The formulation according to any one of claims 1 to 17, wherein the film-forming agent is: Cellulose ethers (e.g., hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose), polyvinyl alcohol, polyquaternium-10, guar gum, hydroxypropyl guar gum, xanthan gum (Keltrals, Xanturals (Xantural 11K, Xantural 180K, Xantural 75, etc.)), gellans (Kelogels), gelatin and gelatin derivatives, aloe gel (Aloe vera gel), amla, carrageenan, oat flour, starch and modified starches (derived from corn, rice, or other plants), gelatin (derived from pig or fish skin), ghatti gum, gum arabic, inulin (derived from chicory), konjac gum, locust bean gum (LBG), fenugreek, marshmallow root, pectin (high methoxy and low methoxy) and modified pectins, quinoa extract, red algae, sora gum, tragacanth gum (TG), and any mixture thereof.

19. 19. Formulation according to any one of claims 1 to 18, wherein the antifungal active agent is: Formulations selected from polyenes (such as amphotericin B and nystatin), azoles (such as itraconazole, fluconazole, efinaconazole, ketoconazole, and miconazole), allylamines (such as terbinafine and butenafine), ciclopirox, amorolfine, tavaborole, griseofulvin, and mixtures thereof, or any pharmaceutically acceptable salts, hydrates, derivatives, or analogs thereof.

20. 20. A formulation according to any one of claims 1 to 19, wherein the antifungal active agent is terbinafine or any pharmaceutically acceptable salt, hydrate, derivative or analogue thereof.

21. 21. The formulation of any one of claims 1 to 20, wherein the antifungal active agent is present in the formulation in an amount of at least about 1 wt%.

22. 22. The formulation of any one of claims 1 to 21, wherein the antifungal active agent is present in the formulation in an amount ranging from about 1 wt% to about 10 wt%.

23. 23. The formulation of any one of claims 1 to 22, wherein the formulation comprises at least 10 wt% of volatile components.

24. 24. The formulation of any one of claims 1 to 23, wherein the average size of the nano-domains ranges from about 5 to 30 nm.

25. A formulation forming a depot of an antifungal active agent on keratinous tissue, the formulation comprises nano-domains dispersed in an aqueous continuous phase; the nano-domains comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol; the aqueous phase comprises water, at least one film-forming agent in an amount of about 1 wt % or less, and at least one keratolytic agent; the total amount of water in the formulation is about 35 wt% to about 55 wt%; the formulation is formulated to form a film having embedded therein the nano-domains upon application to the keratinous tissue; the film has a residence time in the stratum corneum of about 1 hour to 24 hours; formulation.

26. 1. A formulation for topical delivery of an antifungal active agent to keratinous tissue comprising: The formulation comprises nano-domains dispersed in an aqueous continuous phase; the nano-domains comprise the antifungal active agent, at least one hydrophilic surfactant, at least one co-surfactant, and optionally at least one solvent; the aqueous phase comprises water, at least one film-forming agent in an amount of about 1 wt % or less, and at least one keratolytic agent; the total amount of water in the formulation is about 35 wt% to about 55 wt%; formulation.

27. 1. A kit for preparing a formulation for topical delivery of an antifungal active agent to keratinous tissue, comprising: The kit comprises: a first container holding a concentrate comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol; a second container holding an aqueous solution comprising water, at least one film-forming agent in an amount of about 1 wt% or less of the total formulation, and at least one keratolytic agent; mixing said concentrate with said aqueous solution to obtain a topical formulation in the form of nano-domains dispersed in an aqueous continuous phase; Including; wherein the kit is configured to mix the concentrate and the aqueous solution so that the total amount of water in the formulation is about 35 wt % to about 55 wt %. kit.

28. An applicator for topically applying the formulation of any one of claims 1 to 26 to keratinous tissue, comprising: The applicator comprises at least one compartment for holding the formulation and means for applying the formulation to the keratinous tissue.

29. An applicator for topically applying the formulation of any one of claims 1 to 26 to keratinous tissue, comprising: The applicator comprises: a first container holding a concentrate comprising the antifungal active agent, at least one hydrophilic surfactant, at least one alcohol, and at least one polyol; a second container holding an aqueous solution comprising water, at least one film-forming agent in an amount of about 1 wt % or less based on the total weight of the formulation, and at least one keratolytic agent; mixing said concentrate with said aqueous solution to obtain said formulation in the form of nano-domains dispersed in an aqueous continuous phase; and a means for applying the formulation to the keratinous tissue; Including; the applicator is configured to mix the concentrate and the aqueous solution such that the total amount of water in the formulation is about 35 wt % to about 55 wt %; Applicator.

30. 27. A method for the topical delivery of an antifungal active agent to keratinous tissue, comprising applying to said keratinous tissue a formulation according to any one of claims 1 to 26.

31. 27. A method for treating a fungal infection of keratinous tissue, comprising topically applying to said keratinous tissue a formulation according to any one of claims 1 to 26.

32. 27. A method of treating a Tinea ungualium infection of keratinous tissue, comprising topically applying to said keratinous tissue a formulation according to any one of claims 1 to 26.

33. A formulation according to any one of claims 1 to 26 for use in the treatment of fungal infections of keratinous tissue.

34. A formulation according to any one of claims 1 to 26 for use in the treatment of Tinea unguium infections of keratinous tissue.

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