Compositions and methods of treatment

Abstract

The present invention relates to a composition for use in treating fungal infections, comprising a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, the nanoparticles being formed together with and / or in the presence of terbinafine or a derivative or salt thereof, the composition comprising: a) a ratio of terbinafine or a derivative or salt thereof to polymer ranging from about 1:2 to about 1:4; and b) up to about 30% (v / v) alcohol. The composition is particularly suitable as a topical treatment for fungal nail or skin infections. The present invention also relates to methods for producing such compositions and combinations that can be used to produce them. [Selection diagram] Figure 7

Description

[Technical Field]

[0001] The present invention relates to compositions (and methods of producing such compositions) comprising nanoparticles formed from a polymer and terbinafine, which are particularly suitable, but not limited to, for the treatment of fungal nail and / or skin infections. [Background technology]

[0002] Fungal infections are becoming increasingly common in humans and animals, but the treatment of such infections remains difficult due to the toxicity of antifungal compositions, the low solubility of these compositions, and the remote location of some infections that can prove difficult to reach using conventional pharmaceutical formulations.

[0003] Broad-spectrum antifungal drugs, such as amphotericin B, hamycin, filipin, and nystatin, were discovered in the 1960s. However, due to toxicity, only hamycin and nystatin are used topically, while amphotericin B is used systemically. A major advance in antifungal therapy was the introduction of azoles, particularly ketoconazole. The main classes of antifungal drugs currently used are polyenes, azole arylamines, lipopeptides, and pyrimidines. However, polyenes are toxic to mammalian cells. While azoles are well tolerated topically, they have side effects when administered systemically, and there have been several reports of resistance to azoles. Flucytosine is the most commonly used pyrimidine. While flucytosine has excellent tissue penetration, resistance to flucytosine develops rapidly and can cause gastrointestinal side effects. Lipopeptides exhibit low toxicity, and several clinical trials are currently underway to test their efficacy.

[0004] The development of new antifungal drugs is limited because fungi are eukaryotic organisms and destruction of target cells can also damage host cells. The increase in fungal infections and the increased use of antifungal drugs has led to the emergence of resistance among fungi. Antifungal drug resistance has major clinical implications because fungal diseases cause increased morbidity and mortality in immunocompromised patients.

[0005] It is estimated that approximately 40% of newly developed drugs fail due to lack of adequate delivery due to aqueous solubility issues. In the case of topical drug delivery, penetration enhancers are often required to achieve the required drug dose due to the barrier properties of the skin.

[0006] Onychomycosis (more commonly known as fungal nail infection) causes nails to thicken, discolor, deform, and split. If left untreated, the thickened nails can press against the inside of shoes, causing pressure, irritation, and pain. Diabetics, those with peripheral vascular disease, and immunocompromised individuals are particularly at risk for further complications. Fungal nail infections can cause psychological and social problems. The incidence of fungal nail infections increases with age, with a prevalence of approximately 30% in those over 60, with significant incidence in Europe and even higher levels in Asia. Fungal nail infections can also affect one or more toenails and / or fingernails and, if left untreated, can completely destroy the nail.

[0007] Current treatments for fungal nail infections include topical nail lacquers / paints (e.g., amorolfine) applied once or twice weekly for 6–12 months, and / or oral antifungal medications (e.g., terbinafine or itraconazole). Oral antifungal medications can have severe side effects, including gastrointestinal upset and potentially liver failure. Relapse is commonly reported in 25–50% of cases, and many patients do not commit to a course of treatment due to the expected side effects and length of treatment, often beginning treatment only when the disease progresses more rapidly. Current oral or topical treatments can take 6–12 months to work. Oral treatments must saturate the systemic circulation to reach the toe, and increasing the dose increases the risk of gastrointestinal and hepatic complications. Topical treatments are ineffective at penetrating thickened nails and also require high dosages.

[0008] Athlete's foot (also known as tinea pedis, tinea pedis, or moccasin foot) is a fungal infection of the skin usually caused by fungi of the genus Trichophyton, most commonly T. rubrum or T. mentagrophytes. The various parasitic fungi that cause athlete's foot can also cause other skin infections, such as onychomycosis and tinea cruris. Although distinct from fungal nail infections, athlete's foot also presents issues with compliance and duration of treatment.

[0009] Fungal keratitis is inflammation of the cornea caused by a fungal infection. Natamycin ophthalmic suspension is often used for fungal infections, while fluconazole ophthalmic solution is recommended for Candida infections. Amphotericin B eye drops are used in refractory cases, but these eye drops can be toxic in some people.

[0010] Oral candidiasis is a fungal infection of the oral mucosa caused by Candida species. Oral candidiasis can be particularly problematic in immunocompromised patients and is often difficult to treat successfully.

[0011] Patent document 1 discloses a topical composition for treating fungal infections (and a method for producing such a composition) comprising a polymer capable of forming nanoparticles and an antifungal agent. Patent document 2 discloses an antifungal composition comprising nanoparticles formed from a polymer and terbinafine, the nanoparticles comprising particles in the range of 0.5 to 5 nm and / or in the range of 150 to 250 nm. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] International Publication No. 2015044669 [Patent Document 2] International Publication No. 2017 / 006112 Summary of the Invention [Problem to be solved by the invention]

[0013] It is an object of the present invention to address one or more of the above-mentioned problems associated with current antifungal treatments. It is also an object of the present invention to provide a topical antifungal treatment. Additionally, it is an object of the present invention to provide a treatment that allows for better penetration of antifungal agents into certain body tissues, such as the nail and / or dermis, mucous membranes, cornea, and / or sclera. The present invention can be used as a single treatment to address both onychomycosis and tinea pedis, and is desirably easy to apply, resulting in high treatment compliance and a low recurrence rate. [Means for solving the problem]

[0014] According to a first aspect of the present invention there is provided a composition for use in the treatment of a fungal infection comprising a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, wherein the nanoparticles are formed with and / or in the presence of terbinafine or a derivative or salt thereof, the composition comprising: a) a ratio of terbinafine or a derivative or salt thereof to polymer in the range of about 1:2 to about 1:4; b) up to about 30% (v / v) alcohol; A composition is provided comprising:

[0015] According to a first alternative aspect of the present invention there is provided a composition for use as a medicament, said composition comprising a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, said nanoparticles being formed with and / or in the presence of terbinafine or a derivative or salt thereof, said composition comprising: a) a ratio of terbinafine or a derivative or salt thereof to polymer in the range of about 1:2 to about 1:4; b) up to about 30% (v / v) alcohol; A composition is provided comprising:

[0016] According to a further alternative first aspect of the present invention there is provided the use of a composition for the treatment of a fungal infection, said composition comprising a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, the nanoparticles being formed together with and / or in the presence of terbinafine or a derivative or salt thereof, said composition comprising: a) a ratio of terbinafine or a derivative or salt thereof to polymer in the range of about 1:2 to about 1:4; b) up to about 30% (v / v) alcohol; The use of the composition is provided, comprising:

[0017] According to another further alternative first aspect of the present invention there is provided the use of a composition comprising a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof for the manufacture of a medicament for the treatment of fungal infections, wherein the nanoparticles are formed together with and / or in the presence of terbinafine or a derivative or salt thereof, the composition comprising: a) a ratio of terbinafine or a derivative or salt thereof to polymer in the range of about 1:2 to about 1:4; b) up to about 30% (v / v) alcohol; The use of the composition is provided, comprising:

[0018] According to a second aspect of the invention there is provided a composition for use in the treatment of a fungal infection, comprising: (a) terbinafine or a derivative or salt thereof present in an amount ranging from about 0.005% w / w to about 1% w / w; (b) a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, wherein the nanoparticles are formed with and / or in the presence of terbinafine or a derivative or salt thereof, and the polymer is present in an amount in the range of about 0.015% w / w to about 3% w / w; (c) less than about 30% w / w alcohol; (d) up to about 90% w / w water A composition comprising:

[0019] According to a second alternative aspect of the present invention there is provided a composition for use as a medicament, comprising: a) terbinafine or a derivative or salt thereof present in an amount ranging from about 0.005% w / w to about 1% w / w; (b) a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, wherein the nanoparticles are formed with and / or in the presence of terbinafine or a derivative or salt thereof, and the polymer is present in an amount in the range of about 0.015% w / w to about 3% w / w; (c) less than about 30% w / w alcohol; (d) up to about 90% w / w water A composition comprising:

[0020] According to a further alternative second aspect of the present invention there is provided the use of a composition for the treatment of a fungal infection, said composition comprising: a) terbinafine or a derivative or salt thereof present in an amount ranging from about 0.005% w / w to about 1% w / w; (b) a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, wherein the nanoparticles are formed with and / or in the presence of terbinafine or a derivative or salt thereof, and the polymer is present in an amount in the range of about 0.015% w / w to about 3% w / w; (c) less than about 30% w / w alcohol; (d) up to about 90% w / w water The use of the composition is provided, comprising:

[0021] According to another further alternative second aspect of the present invention, a) terbinafine or a derivative or salt thereof present in an amount ranging from about 0.005% w / w to about 1% w / w; (b) a polymer capable of forming nanoparticles and terbinafine or a derivative or salt thereof, wherein the nanoparticles are formed with and / or in the presence of terbinafine or a derivative or salt thereof, and the polymer is present in an amount in the range of about 0.015% w / w to about 3% w / w; (c) less than about 30% w / w alcohol; (d) up to about 90% w / w water The present invention provides a use of a composition comprising:

[0022] Such compositions of the second aspect preferably comprise: (a) terbinafine or a derivative or salt thereof present in an amount of about 0.1% w / w; (b) a polymer present at about 0.3% w / w; (c) an alcohol present at about 20% w / w; (d) Water present at a maximum of approximately 79.6% w / w may include:

[0023] Aspects of both the first and second aspects of the present invention may include interchangeable components and amounts of these components as described below, where appropriate.

[0024] Preferably, the polymer comprises a linear and / or branched or cyclic polymonoguanide / polyguanidine, polybiguanide, analogue or derivative thereof. The linear and / or branched or cyclic polymonoguanide / polyguanidine, polybiguanide, analogue or derivative thereof may be according to Formula 1a or Formula 1b below, examples of which are provided in Tables A and B below. Formula 1a

[0025] [ka]

[0026] Formula 1b

[0027] [ka]

[0028] During the ceremony, "n" refers to the number of repeating units in the polymer, and n can vary from 2 to 1000, for example, from 2 or 5 to 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, or 900. G1 and G2 independently represent a cationic group containing biguanide or guanidine, and L1 and L2 are directly linked to the nitrogen atom of the guanide. Thus, the biguanide or guanidine group is integral with the polymer backbone. The biguanide or guanidine group is not a side chain moiety of Formula 1a.

[0029] Examples of cationic groups are: Biguanides

[0030] [ka]

[0031] (PHMB, etc.) or Guanidine

[0032] [ka]

[0033] (PHMG, etc.) is.

[0034] In the present invention, L1 and L2 are linking groups between the G1 and G2 cationic groups of the polymer. L1 and L2 are independently C1-C 140 Aliphatic groups containing carbon atoms, such as methylene, ethylene, propylene, C4, C5, C6, C7, C8, C9 or C 10 Alkyl groups such as C1-C 10 , -C 20 , -C 30 , -C 40 , -C 50 , -C 60 , -C 70 , -C 80 , -C90 , -C 100 , -C 110 , -C 120 , -C 130 or -C 140 , alkyl; or L1 and L2 (independently) can represent C1-C 140 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9, or C 10 ;C 1‐ C 10 , -C 20 , -C 30 , -C 40 , -C 50 , -C 60 , -C 70 , -C 80 , -C 90 , -C 100 , -C 110 , -C 120 , -C 130 , or -C 140 ), cycloaliphatic, heterocyclic, aromatic, aryl, alkylaryl, arylalkyl, oxyalkylene radical; or L1 and L2 (independently) may be a polyalkylene radical optionally interrupted by one or more, preferably one, oxygen, nitrogen, or sulfur atoms, functional groups, and saturated or unsaturated cyclic moieties. Examples of suitable L1 and L2 are the groups listed in Table A.

[0035] L1, L2, G1, and G2 may be modified with aliphatic, cycloaliphatic, heterocyclic, aryl, alkaryl, and oxyalkylene radicals.

[0036] N and G3 are preferably terminal groups. Typically, polymers used in the present invention have terminal amino (N) and cyanoguanidine (G3) or guanidine (G3) end groups. Such end groups can be modified by conjugation to aliphatic, cycloaliphatic, heterocyclic, heterocyclic, aryl, alkylaryl, arylalkyl, or oxyalkylene radicals (e.g., using 1,6-diaminohexane, 1,6-di(cyanoguanidino)hexane, 1,6-diguanidinohexane, or 4-guanidinobutyric acid). Additionally, end groups can be modified by conjugation to receptor ligands, dextran, cyclodextrin, fatty acids or fatty acid derivatives, cholesterol or cholesterol derivatives, or polyethylene glycol (PEG). Optionally, the polymer can be terminated with guanidine or biguanide or cyanoamine or amine or cyanoguanidine at positions N and G3, or with a cyanoamine at position N and a cyanoguanidine at position G3, or with a guanidine at position N and a cyanoguanidine at position G3, or with an L1 amine at G3 and a cyanoguanidine at position N. G3 can be an L1-amine, an L2-cyanoguanidine, or an L2-guanidine. Depending on the polymerization number (n) or the breakage and side reactions of the polymer chain during synthesis, a heterogeneous mixture of end groups, as shown by way of example above, can occur. Thus, the N and G3 groups can be interchangeable / exist as a heterogeneous mixture, as described above. Alternatively, N and G3 can be absent, and the polymer can be cyclic, in which case the respective terminal L1 and G2 groups are directly bonded to each other.

[0037] In Formula 1b, X may be present or absent. L3, L4, and X are as described above for "L1 or L2." Thus, L3, L4, and X are linking groups between the G4 and G5 cationic groups of the polymer. L3, L4, and X are independently C1-C 140 Aliphatic groups containing carbon atoms, such as methylene, ethylene, propylene, C4, C5, C6, C7, C8, C9 or C 10 Alkyl groups such as C1-C 10 , -C 20 , -C30 , -C 40 , -C 50 , -C 60 , -C 70 , -C 80 , -C 90 , -C 100 , -C 110 , -C 120 , -C 130 or -C 140 or L3 and L4 and X may independently represent C1-C 140 (e.g. C1, C2, C3, C4, C5, C6, C7, C8, C9, or C 10 ;C 1‐ C 10 , -C 20 , -C 30 , -C 40 , -C 50 , -C 60 , -C 70 , -C 80 , -C 90 , -C 100 , -C 110 , -C 120 , -C 130 , or -C 140 L3, L4 and X may be cycloaliphatic, heterocyclic, aromatic, aryl, alkylaryl, arylalkyl, oxyalkylene radicals, or L3, L4 and X may independently be polyalkylene radicals optionally interrupted by one or more, preferably one, oxygen, nitrogen, or sulfur atoms, functional groups, and saturated or unsaturated cyclic moieties. Examples of suitable L3, L4 and X are the groups listed in Table B.

[0038] "G4" and "G5" are cationic moieties and may be the same or different. At least one of them is a biguanidine moiety or a carbamoylguanidine, and the other may be as described above (biguanidine or carbamoylguanidine) or an amine. For the avoidance of doubt, in Formula 1b, the cationic moieties G4 and G5 do not contain only a single guanidine group. For example, G4 and G5 typically do not contain a single guanidine group. Examples of such compounds are polyallylbiguanide, poly(allylbiguanidonio-co-allylamine), poly(allylcarbamoylguanidino-co-allylamine), and polyvinyl biguanide, as listed in Table B.

[0039] An example of polyallyl biguanide is shown below.

[0040] [ka]

[0041] In the case of polyallylvignidine, L3 and L4 are identical, and G4 and G5 are similar, so polyallylbiguanide can be simplified to:

[0042] [ka]

[0043] An example of poly(allylcarbamoylguanidonio-co-allylamine) is shown below.

[0044] [ka]

[0045] Polymers for use in the present invention generally have a counterion attached to the polymer. Suitable counterions include, but are not limited to, halides (e.g., chloride), phosphates, lactates, phosphonates, sulfonates, aminocarboxylates, carboxylates, hydroxycarboxylates, organophosphates, organophosphonates, organosulfonates, and organosulfates.

[0046] Polymers for use in the present invention can be either heterogeneous mixtures of polymers with different "n" numbers, or homogeneous fractions containing a particular "n" number that have been purified by standard purification methods. As noted above, the polymers can be cyclic, as well as branched.

[0047] Preferred numbers for "n" include 2 to 250, 2 to 100, 2 to 80, and 2 to 50.

[0048] [Table 1]

[0049] [Table 2]

[0050] [Table 3]

[0051] The polymers used may comprise linear, branched or dendritic molecules. The polymers may comprise a combination of linear, branched or dendritic molecules. The polymers may comprise one or any combination of molecules of Formula 1a or Formula 1b, for example, as described above.

[0052] For example, the polymer can include one or more of polyhexamethylene biguanide (PHMB), polyhexamethylene monoguanide (PHMG), polyethylene biguanide (PEB), polytetramethylene biguanide (PTMB), or polyethylene hexamethylene biguanide (PEHMB). Some examples are listed in Tables A and B.

[0053] Thus, the polymer may comprise a homogeneous or heterogeneous mixture of one or more of polyhexamethylene biguanide (PHMB), polyhexamethylene monoguanide (PHMG), polyethylene biguanide (PEB), polytetramethylene biguanide (PTMB), polyethylene hexamethylene biguanide (PEHMB), polymethylene biguanide (PMB), poly(allylbiguanidonio-co-allylamine), poly(N-vinyl biguanide), polyallyl biguanide, etc. The most preferred polymer comprises polyhexamethylene biguanide (PHMB).

[0054] The term "terbinafine or a derivative or salt thereof" is intended to mean a pharmaceutically active substance related to terbinafine hydrochloride, a synthetic allylamine antifungal drug originally marketed under the trade name Lamisil®. The term is also intended to include pharmaceutical variations, derivatives, and salt substitutes of terbinafine hydrochloride, such as non-toxic organic or inorganic, acid or base addition salts in pharmaceutically acceptable form.

[0055] Terbinafine or a derivative or salt thereof may be present in an amount ranging from about 5 to about 1000 μg / ml. Preferably, terbinafine or a derivative or salt thereof may be present in an amount ranging from about 5 to about 600 μg / ml. More preferably, terbinafine or a derivative or salt thereof may be present in an amount ranging from about 25 to about 200 μg / ml. Even more preferably, terbinafine or a derivative or salt thereof may be present in an amount ranging from about 50 to about 150 μg / ml. Most preferably, terbinafine or a derivative or salt thereof may be present at about 100 μg / ml.

[0056] The polymer may be present in an amount ranging from about 15 to about 3000 μg / ml. Preferably, the polymer is present in a range of about 15 to about 1800 μg / ml. More preferably, the polymer is present in a range of about 75 to about 600 μg / ml. Even more preferably, the polymer is present in a range of about 150 to about 450 μg / ml. Most preferably, the polymer is present at about 300 μg / ml. Preferably, the polymer comprises PHMB.

[0057] The alcohol may be present in an amount ranging from about 5% to about 29% or about 30% (v / v). Preferably, the alcohol is present in an amount ranging from about 10% to about 29% or about 30% (v / v). More preferably, the alcohol is present in an amount ranging from about 20% to about 29% or about 30% (v / v). Even more preferably, the alcohol is present in an amount up to about 25% or 23% (v / v). Most preferably, the alcohol is present in an amount up to about 20% (v / v).

[0058] The alcohol preferably comprises ethanol, but may also comprise other alcohols (alone or in combination) such as methanol or propanol.

[0059] The composition may also contain water. Preferably, the water is distilled water. The water may be present in an amount ranging from about 70% to about 95% (v / v). Preferably, the water is present in an amount ranging from about 70% to about 90% (v / v). More preferably, the water is present in an amount ranging from about 70% to about 80% (v / v). Even more preferably, the water is present in an amount greater than about 77% (v / v). Most preferably, the water is present in an amount up to about 90% (v / v), up to about 80% (v / v), or about 79.6% (v / v).

[0060] Terbinafine or a derivative or salt thereof may be present in an amount ranging from about 0.005% w / w to about 1.0% w / w. Preferably, terbinafine or a derivative or salt thereof may be present in an amount ranging from about 0.005% w / w to about 0.6% w / w. More preferably, terbinafine or a derivative or salt thereof is present in an amount ranging from about 0.025% w / w to about 0.2% w / w. Even more preferably, terbinafine or a derivative or salt thereof is present in an amount ranging from about 0.05% w / w to about 0.15% w / w. Most preferably, terbinafine or a derivative or salt thereof is present at about 0.1% w / w.

[0061] The polymer may be present in an amount ranging from about 0.15% w / w to about 3% w / w. Preferably, the polymer is present in a range from about 0.15% w / w to about 1.8% w / w. More preferably, the polymer is present in a range from about 0.75% w / w to about 0.6% w / w. Even more preferably, the polymer is present in a range from about 0.15% w / w to about 0.45% w / w. Most preferably, the polymer is present at about 0.3% w / w. Preferably, the polymer comprises PHMB.

[0062] The alcohol may be present in an amount ranging from about 5% w / w to about 29% w / w. Preferably, the alcohol is present in an amount ranging from about 10% w / w to about 29% w / w. More preferably, the alcohol is present in an amount ranging from about 20% w / w to about 29% w / w. Even more preferably, the alcohol is present in an amount up to about 29% w / w, more preferably in an amount up to about 25%, even more preferably in an amount up to about 23% w / w, and most preferably, the alcohol is present in an amount up to about 20% w / w.

[0063] The alcohol preferably comprises ethanol, but may also comprise other alcohols (alone or in combination) such as methanol or propanol.

[0064] The composition may also contain water. Preferably, the water is distilled water. The water may be present in an amount ranging from about 70% w / w to about 95% w / w. Preferably, the water is present in an amount ranging from about 70% w / w to about 90% w / w. More preferably, the water is present in an amount ranging from about 70% w / w to about 80% w / w. Even more preferably, the water is present in an amount up to about 70% w / w, and even more preferably, in an amount up to about 77% w / w. Most preferably, the alcohol is present in an amount up to about 90% w / w, up to about 80% w / w, or up to 79.6% w / w.

[0065] Preferably, the composition contains only terbinafine, polymer, alcohol and water, meaning that no further excipients or solvents are included in the composition.

[0066] The ratio of terbinafine or its derivative or salt to polymer can be about 1:3±0.75. The ratio of terbinafine or its derivative or salt to polymer is preferably about 1:3±0.5. The ratio of terbinafine or its derivative or salt to polymer is more preferably about 1:3±0.25. The ratio of terbinafine or its derivative or salt to polymer is even more preferably about 1:3±0.1. The ratio of terbinafine or its derivative or salt to polymer is most preferably about 1:3.

[0067] The nanoparticles may include particles formed of two species of different diameters, a first species in the range of 0.5-5 nm and a second species in the range of 50-350 nm.

[0068] The relative amounts of the first species to the second species are generally equal to each other, or one species may be the more predominant species in the composition.

[0069] The first type of particles are preferably within the range of 0.5 to 3 nm. The first type of particles are more preferably within the range of 0.5 to 2.5 nm. The first type of particles are most preferably within the range of 0.5 to 2 nm. The second type of particles are preferably within the range of 75 to 325 nm. The second type of particles are more preferably within the range of 100 to 300 nm. The second type of particles are most preferably within the range of 150 to 200 nm or 215 nm.

[0070] The average size of the particles of the first type is preferably in the range of 0.5 to 1.5 nm. More preferably, the average size of the particles of the first type is in the range of 0.6 to 1.4 nm. Even more preferably, the average size of the particles of the first type is in the range of 0.7 to 1.2 nm. Most preferably, the average size of the particles of the first type is in the region of about 0.9 nm.

[0071] The average size of the second type of particles is preferably within the range of 50 to 350 nm. The average size of the second type of particles is more preferably within the range of 100 to 300 nm. The average size of the second type of particles is even more preferably within the range of 150 to 200 nm. The average size of the second type of particles is most preferably within the range of about 160 to about 176 nm.

[0072] The average modal size of the second type of particles is preferably within the range of 150 to 225 nm. The average modal size of the second type of particles is more preferably within the range of 155 to 220 nm. The average modal size of the second type of particles is even more preferably within the range of 160 to 215 nm. The average modal size of the second type of particles is most preferably within the range of about 164 to about 211 nm.

[0073] The composition may comprise a topically applied composition.

[0074] It will be apparent to those skilled in the art that the composition may further comprise one or more of the following ingredients: buffers, excipients, binders, oils, solvents, water, emulsifiers, glycerin, antioxidants, preservatives, and fragrances, or any additional ingredients typically found in pharmaceuticals, particularly topical creams and ointments. Furthermore, the composition may be in several forms, such as a paste or suspension. The composition may be formulated for use with a spray device or for use in conjunction with a microneedle array delivery system. When a microneedle array is utilized, the microneedle array may be incorporated into an adhesive patch.

[0075] In some applications, the composition may further comprise a penetrating agent to allow delivery of the terbinafine agent to the infected area. For example, urea may be used to allow the nanoparticles to penetrate the nail of an individual suffering from a fungal nail infection where the infection is located under the nail or within the nail itself. In addition, a solvent may be utilized to allow dissolution of one or more components of the composition, such as terbinafine, into the solution.

[0076] The compositions of the invention may be administered intranasally or by inhalation and may conveniently be delivered in the form of a dry powder inhaler, or an aerosol spray presentation from pressurized containers, pumps, sprayers, or nebulizers using a suitable propellant such as dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, hydrofluoroalkanes such as 1,1,1,2-tetrafluoroethane (HFA134A) or 1,1,1,2,3,3,3-heptafluoropropane (HFA227EA3), carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container, pump, sprayer, or nebulizer may contain a solution or suspension of the composition using, for example, a mixture of ethanol as a solvent and a propellant, which may further contain a lubricant, such as sorbitan trioleate. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated to contain a powder mix of the composition of the invention and a suitable powder base such as lactose or starch.

[0077] Aerosol or dry powder formulations are preferably arranged so that each metered dose or "puff" contains at least 1 μg of composition for delivery to the patient. It will be appreciated that the total daily dose from an aerosol will vary from patient to patient and may be administered in a single dose or, more commonly, in divided doses throughout the day.

[0078] Alternatively, the compositions of the present invention may be administered in the form of a suppository or pessary, or may be applied topically in the form of a lotion, solution, cream, ointment, or dusting powder. The compositions of the present invention may also be administered transdermally, for example, by the use of a skin patch. The compositions of the present invention may also be administered via the ocular route, particularly to treat eye diseases.

[0079] For ophthalmic use, the compositions of the present invention may be formulated using nanoparticle systems or as micronized suspensions in isotonic, pH-adjusted, sterile saline, or preferably as solutions in isotonic, pH-adjusted, sterile saline, optionally in combination with a preservative such as benzylalkonium chloride. Alternatively, the compositions of the present invention may be formulated in an ointment such as petrolatum.

[0080] For topical application to the skin, the compositions of the present invention can be formulated as a suitable ointment containing the active compound suspended or dissolved in a mixture of one or more of mineral oil, liquid petrolatum, white petrolatum, propylene glycol, a polyoxyethylene polyoxypropylene compound, an emulsifying wax, and water, or as a suitable lotion or cream containing the active compound suspended or dissolved in a mixture of one or more of mineral oil, sorbitan monostearate, polyethylene glycol, liquid paraffin, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol, and water.

[0081] The compositions described hereinabove may be used to treat several fungal infections. However, the compositions are particularly suitable for treating fungal nail infections, athlete's foot, or other types of fungal skin / dermatophyte infections, such as jock itch, ringworm of the body (tinea corporis), ringworm of the head, and other "ringworm" type infections. The present invention is also suitable for treating yeast infections, such as, but not limited to, intertrigo, tinea versicolor, and thrush (Candida albicans). Fungal infections may include dermatophyte infections. However, the present invention may also be used to treat or modulate yeast infections and / or colonization. The compositions described hereinabove may be for the treatment or management of fungal infections. The treatment may be a topical treatment.

[0082] Additionally, the compositions described herein above may be used to treat several fungal diseases, such as treating fungal nail infections and athlete's foot.

[0083] According to a further aspect of the present invention, there is provided a method of producing a composition for use in treating fungal nail or skin infections, comprising mixing a polymer capable of forming nanoparticles with terbinafine or a salt or derivative thereof in a ratio of about 1:2 to about 1:4 under conditions suitable to allow the formation of nanoparticles, and adding up to about 30% (v / v) alcohol.

[0084] This method is preferably used to produce the compositions described in relation to the first aspect of the invention.

[0085] Nanoparticles can be formed using various methods, and it is assumed that the nanoparticles are formed as a complex of polymer and terbinafine. However, polymer nanoparticles can be formed independently and then incubated with terbinafine together or separately in any order. Terbinafine can be absorbed or attached to the nanoparticles in a manner that maintains the efficacy of the antifungal agent against fungi and the penetration-enhancing effect of the nanoparticles.

[0086] In a further aspect of the invention, a) a polymer capable of forming nanoparticles with terbinafine or a derivative or salt thereof; b) terbinafine or a derivative or salt thereof, c) Alcohol wherein terbinafine or a derivative or salt thereof is provided in a ratio to polymer in the range of about 1:2 to about 1:4, and the alcohol is provided in an amount up to about 30% (v / v).

[0087] This combination is preferably used to produce the compositions described herein above in relation to the first and second aspects, or in the methods described herein above in relation to the further aspects.

[0088] The mixture can be further processed to select nanoparticles within the required size range using several techniques such as centrifugation, electrophoresis, chromatography or filtration. The measurement of the size / diameter of the nanoparticles is preferably carried out using dynamic light scattering analysis.

[0089] The present invention may further comprise formulating the composition into a topical medicament.

[0090] It will also be apparent that this method may be utilized to produce the compositions described hereinabove.

[0091] In yet another aspect of the present invention, there is provided a combination of a composition as described hereinabove with a microneedle array for use in treating fungal nail infections. The microneedle array may be incorporated into an adhesive patch. The microneedles may be less than 2 mm in length. More preferably, the microneedles are less than 1.5 mm in length. Most preferably, the microneedles are less than 1 mm in length. Preferably, microneedles less than 500 μm in length are inserted into the skin. More preferably, microneedles less than 400 μm in length are inserted into the skin. Most preferably, microneedles between about 300 and 200 μm in length are inserted into the skin. Preferably, the microneedles administer the composition to the dermis and / or epidermis.

[0092] Embodiments of the present invention will now be described, by way of example only, with reference to the following experiments and the accompanying drawings. [Brief explanation of the drawings]

[0093] [Figure 1]Figure 1A is a histogram showing the size distribution of particles formed by mixing 0.1 mg / ml terbinafine in 30% ethanol and incubating at room temperature for at least 24 hours. The particle size distribution was measured using a Malvern Instruments Nanosight LM10 (particle size range = 50-800 nm, particle count = 0.5 x 10 particles / ml). Figure 1B is a video frame image of particles formed by mixing 0.1 mg / ml terbinafine in 30% ethanol and incubating at room temperature for at least 24 hours. The particles were visualized using a Malvern Instruments Nanosight LM10. [Figure 2] Figure 2A is a histogram showing the size distribution of particles formed by mixing 0.1 mg / ml terbinafine and 0.3 mg / ml PHMB in 30% ethanol and incubating at room temperature for at least 24 hours. The particle size distribution was measured using a Malvern Instruments Nanosight LM10 (particle size range = 100-300 nm, modal size = 195 nm, particle count = 12 x 10 particles / ml). Figure 2B is a video frame image of particles formed by mixing 0.1 mg / ml terbinafine and 0.3 mg / ml PHMB in 30% ethanol and incubating at room temperature for at least 24 hours. Particles were visualized using a Malvern Instruments Nanosight LM10. [Figure 3] 1 is a graph showing the size distribution by intensity of nanoparticles formed with 0.3 mg / ml PHMB / 0.1 mg / ml terbinafine nanoparticles as measured with a Malvern instruments Zetasizer. [Figure 4]Figure 4A shows a graph of the number of terbinafine and PHMB nanoparticles per ml versus time. Nanoparticle stability was evaluated for 170 days. A solution of BB0305 in 30% (v / v) ethanol at a concentration equivalent to 0.1 mg / ml of terbinafine was stored in a clear plastic screw-cap tube under ambient temperature and light conditions. Samples were removed on the indicated days and analyzed for total nanoparticle counts / ml. Figure 4B shows a graph of the mode particle size of terbinafine and PHMB nanoparticles versus time. Nanoparticle stability was evaluated for 170 days. A solution of BB0305 in 30% (v / v) ethanol at a concentration equivalent to 0.1 mg / ml of terbinafine was stored in a clear plastic screw-cap tube under ambient temperature and light conditions. Samples were removed on the indicated days and analyzed for total nanoparticle counts / ml. [Figure 5] Figure 1 shows the results of nail immersion experiments with BB0305 (terbinafine and PHMB nanoparticles) and terbinafine alone. 3 mm human nail discs from healthy nail clippings were suspended in solutions of BB0305 and terbinafine at equivalent concentrations of the active ingredients (0.1, 1, and 10 mg / ml). Washed and dried nails were dissolved in 5 M NaOH, and terbinafine levels were determined by quantitative LC-MS / MS. [Figure 6] Figure 6A is a photograph of a histological sample of a frozen section of nail removed from a healthy human volunteer that was immersed in a solution of 0.25 mg / ml PHMB, 0.05 mg / ml FITC-labeled PHMB (one fluorescently labeled PHMB per five spikes), and 0.1 mg / ml terbinafine at 32°C for 24 hours (scale bar approximately 100 μm). Figure 6B is a photograph of a histological sample of a frozen section of nail removed from a healthy human volunteer that was immersed in a manner similar to that shown in Figure 6A. Two images are presented: one of the entire nail section (scale bar approximately 100 μm on the left) and one of only the central region of the nail (scale bar approximately 20 μm on the right). Staining that penetrates at least 20 μm into the nail structure itself is clearly visible around the edge of the nail. [Figure 7]This is a scatter plot showing the penetration of terbinafine into healthy human nail samples treated with BB0305 (terbinafine and PHMB nanoparticles) or a terbinafine solution. Terbinafine concentrations were determined by LC-MS / MS in ethanol washes from healthy human nails treated with BB0305 or a 0.1 mg / ml terbinafine solution. Individual samples are plotted (diamond markers). All terbinafine samples (n = 4) were below the limit of detection (<0.1 ng / ml). The two sample sets were compared using an unpaired Student's parametric t-test, assuming that the concentration of terbinafine passing through the terbinafine solution-treated nail was 0.1 ng / ml (the limit of LC-MS / MS detection). The p-value for this test was 0.04. [Figure 8] This is a scatter plot showing the levels of terbinafine bound to nails treated with BB0305 (terbinafine and PHMB nanoparticles) or a solution of terbinafine. The concentration of terbinafine was determined by LC-MS in lysed nail samples from healthy human nails treated with BB0305 or a 0.1 mg / ml solution of terbinafine. Individual samples are plotted. Two sample sets were compared using an unpaired Student's parametric t-test. The p-value for this test was 0.02. [Figure 9] Figure 9A is a scatter plot summarizing Franz cell data from the addition of multiple doses of BB0305 (terbinafine and PHMB nanoparticles) to human nails, examining the concentration of terbinafine (determined by LC-MS / MS) in ethanol washes from healthy human nails treated with multiple small doses of BB0305. Figure 9B is a scatter plot summarizing Franz cell data from the addition of multiple doses of BB0305 (terbinafine and PHMB nanoparticles) to human nails, examining the concentration of terbinafine (determined by LC-MS / MS) in lysed nail samples from healthy human nails treated with multiple small doses of BB0305. [Figure 10]Figures 10A-10E are photographic images of yeast extract peptone dextrose (YEPD) agar plates containing Trichophyton mentagrophytes after 4 days of incubation at 30°C. A 10 mm sterile paper disk was placed in the center of the Trichophyton mentagrophyte lawn on each plate. 40 μl of double-distilled water or various concentrations of terbinafine solution was spotted onto each paper disk. The concentrations of terbinafine solution used were 0 μg / ml (control, Figure 7A), 0.06 μg / ml (Figure 7B), 0.6 μg / ml (Figure 7C), 6.00 μg / ml (Figure 7D), and 60.0 μg / ml. Figure 8 is a plan view of a finger with a nail to be treated with a microneedle patch to deliver a composition of the present invention. [Figure 11] Figures 11A and 11B are photographic images of YEPD plates evaluating the efficacy of BB0305 (terbinafine and PHMB nanoparticles) and terbinafine samples against T. mentagrophytes through healthy human nails. T. mentagrophyte lawns were spread on YEPD agar plates supplemented with 50 μg / ml chloramphenicol. Aqueous samples from Franz cell collection chambers after 7 days of treatment of healthy human nails with either 0.1 mg / ml terbinafine (Figure 11A) or BB0305 (Figure 11B) were spotted onto 10 mm paper discs. The discs were placed in the center of the tinea plate and then incubated at 30°C for 5 days to allow fungal growth. The antifungal activity of terbinafine from the BB0305-treated nails is seen as a clearance zone around the disc. [Figure 12] Scatter plot showing terbinafine concentrations in ethanol washes from nails treated with multiple doses of BB0305 (terbinafine and PHMB nanoparticles). Terbinafine concentrations (determined by LC-MS / MS) in ethanol washes from healthy human nails treated with multiple small doses of BB0305 in either 20% (v / v) ethanol (left) or 30% (v / v) ethanol (right). [Figure 13]Scatter plot showing terbinafine concentrations in dissolved nails from nails treated with multiple doses of BB0305 (terbinafine and PHMB nanoparticles) and healthy human nails treated with multiple small doses of BB0305 in either 20% (v / v) ethanol (left) or 30% (v / v) ethanol (right). [Figure 14] FIG. 1 is a plan view of a finger having a nail to be treated with a microneedle patch to deliver a composition of the present invention. [Figure 15] FIG. 15 is a cross-sectional view of the finger shown in FIG. 14. [Figure 16] FIG. 1 is a cross-sectional view of a microneedle patch. DETAILED DESCRIPTION OF THE INVENTION

[0094] The purpose of the following experiment was to determine whether the cellular delivery of antifungal drugs (particularly for the treatment of onychomycosis) could be enhanced using a nanotechnology-based delivery system employing the cationic polymer polyhexamethylene biguanide (PHMB). PHMB is an inexpensive, readily available disinfectant and antiseptic commonly used in dressings, swimming pools, and contact lens solutions. Its antiseptic action is thought to work by disrupting the cell membranes of living organisms, thereby causing leakage of cellular contents. The experiment also evaluated the effect of various concentrations and formulations of the antifungal agent on fungal species to allow for the determination of appropriate dosage levels and formulations.

[0095] Nanoparticle formation by terbinafine and PHMB First, experiments were conducted to form nanoparticles of terbinafine and PHMB, which were designated BB0305 throughout the study.

[0096] BB0305 nanoparticles were initially formed by combining terbinafine.HCl and PHMB in 30% (v / v) ethanol to a final terbinafine concentration equivalent to 0.1 mg / ml, 1 mg / ml, or 10 mg / ml. Nanoparticle formation was routinely confirmed using a Nanosight LM10 instrument (Malvern Instruments). Additional nanoparticle analysis was performed using a Zetasizer (Malvern Instruments). Control terbinafine solutions were made by dissolving terbinafine.HCl in 30% (v / v) ethanol to a final concentration of 0.1 mg / ml, 1 mg / ml, or 10 mg / ml.

[0097] It was found that initial formulation with terbinafine and PHMB in 30% ethanol significantly increased the number of nanoparticles formed and resulted in the formation of more monodisperse nanoparticles than those formed with terbinafine alone in 30% ethanol. The results demonstrated that PHMB can be used to form monodisperse nanoparticles with antifungal agents that can be further used in the preparation of topical medications for the subsequent treatment of a variety of potential fungal infections.

[0098] Nanoparticle Analysis Solutions of BB0305 clearly showed the formation of nanoparticles that were stable at room temperature for more than 5 months.

[0099] In the first analysis, nanoparticles in solution were detected using a Nanosight LM10 nanosizer (Malvern Instruments). In this analysis, the terbinafine solution contained detectable particles (Figure 1A). However, the number of particles per ml of solution was relatively low (0.5 × 10 for a solution of 0.1 mg / ml terbinafine in 30% (v / v) ethanol). 8 / ml), the particle size was heterogeneous and polydisperse. The presence of these particles was thought to be at least partly due to the hydrophobic nature of the compound, which was not completely solubilized and therefore contained various drug aggregates in aqueous solution.

[0100] In contrast, a solution of BB0305 at a concentration equivalent to 0.1 mg / ml of terbinafine produced numerous (typically 5–10 × 10) vesicles with diameters in the range of 170–210 nm (as shown in Figure 1B). 8 Monodisperse particles of 1000 nanoparticles / ml were observed. Higher concentrations of BB0305 (equivalent concentrations of terbinafine at 1 mg / ml and 10 mg / ml, respectively) were also produced for use in initial nail immersion experiments (described below), but these exhibited a loss of monodispersity, which was attributed to the higher polymer concentration allowing the formation of larger nanoparticle aggregates (data not shown).

[0101] LM10 uses direct visualization of particles by microscope; particles are tracked by a video camera, and size is calculated using the Einstein-Stokes equation, which relates particle velocity in solution to particle diameter. This video capture also allows for qualitative assessment during analysis of various formulations. However, this instrument has a lower cutoff range for analysis, approximately 20 nm in diameter. Therefore, BB0305 nanoparticles were also analyzed using a Zetasizer (Malvern Instruments), which calculates particle size using dynamic light scattering and can detect particles down to 0.3 nm in size. This analysis identified a second population of nanoparticles in BB0305 with diameters in the 0.3–2 nm range that was not detected by LM10 (as shown in Figure 3).

[0102] Finally, the long-term stability of a solution of BB0305 in 30% (v / v) ethanol (as shown in Figures 4A and 4B) was assessed by measuring the nanoparticles in solution over a 170-day period. Because the analysis was performed using a Nanosight LM10, only the larger diameter BB0305 nanoparticle population was considered. This analysis demonstrated that, although there was an initial slight decrease in the number of particles in solution and some variation in the modal size of the particles, BB0305 nanoparticles were essentially stable at room temperature under ambient light conditions for at least 5 months.

[0103] Nail immersion experiment Healthy human nail samples were preincubated in ddH2O at 30°C for 2 hours. Next, 3 mm discs were cut from the nail clippings using a 3 mm biopsy punch. The nail discs were placed in 250 μl of test solution in a 1.5 ml tube and incubated at 32°C for 24 hours in a humidified incubator with 0.5% (v / v) CO2. The nail samples were removed and washed in a large volume of ddH2O to remove all drug solution from the nail. The nails were dried with clean tissue and then weighed. The weighed nails were dissolved in 200 μl of 5 M NaOH at 37°C for 1 hour. After dissolution, 200 μl of methanol was added to the sample to ensure that all terbinafine in the sample remained in solution. The amount of terbinafine in the dissolved nail sample solutions was analyzed using quantitative LC-MS / MS mass spectrometry.

[0104] Quantitative mass spectrometry (MS) was used to detect and quantify terbinafine in the samples. Sample identifiers were decontaminated before submission for analysis. Analysis was performed using high-performance liquid chromatography with tandem mass spectrometry (LC-MS / MS) on a Waters Acquity I-Class UPLC chromatography system coupled to a Waters Xevo TQ-S mass spectrometer. Terbinafine levels were quantified against drug standards on a terbinafine standard curve ranging from 0.1 to 10 ng / ml. Samples were diluted appropriately to fall within the standard curve. Samples with terbinafine concentrations below 0.1 ng / ml were below the detection limit of this assay. Terbinafine concentrations in nail samples were normalized to the total volume of nail and expressed as terbinafine (ng) / nail (mg).

[0105] Initial studies focused on the use of simple nail "immersion" experiments in which 3 mm discs of human nail were incubated in various formulations and test solutions. These experiments could only detect whether terbinafine bound to the nail, but did not provide direct evidence of nail penetration. However, these experiments were technically straightforward, relatively high-throughput, and capable of evaluating a variety of formulations.

[0106] As shown in Figure 5, terbinafine in a simple solution binds to human nail samples. The amount of terbinafine bound to the nail was concentration-dependent between 0.1 mg and 1 mg / ml, but no further enhancement was observed at higher concentrations of 10 mg / ml. This suggests that above 1 mg / ml, the nail disc reaches an upper limit for the amount of terbinafine that can be bound.

[0107] Figure 5 also demonstrates that BB0305 binds to human nail samples. At a terbinafine equivalent concentration of 0.1 mg / ml, no significant differences were observed between BB0305 and terbinafine solutions; both produced equivalent drug concentrations in the dissolved nail samples. As observed with terbinafine, there was an increase in drug binding between BB0305 at 0.1 mg / ml and 1 mg / ml equivalent terbinafine concentrations, but no further increase at 10 mg / ml. Again, this suggests that above 1 mg / ml, BB0305 reaches the limit of the amount of drug it can wick into the nail disc over a 24-hour period. However, the maximum amount of drug that could bind to BB0305-treated nails was much higher (1.3-2.5-fold) compared to terbinafine-treated nails. This increase was not due to differences in the available nail surface or overall nail material, as all tests were performed on 3 mm nail discs, which have essentially the same surface area, and weight variation between samples was less than 10%. These experiments therefore suggest that BB0305 increases the maximum amount of terbinafine that can bind to human nails, demonstrating that this formulation enhances drug delivery into tissues.

[0108] Although nail immersion experiments suggested that BB0305 enhanced drug delivery into the nail, it was not possible to distinguish between increased drug penetration into the nail and increased drug adhesion to the nail. Therefore, we decided to proceed with histological studies of the 0.1 mg / ml BB0305 formulation to attempt to obtain direct evidence of nanoparticle penetration into tissue. This concentration was chosen because it produced the most consistent nanoparticle formulations, whereas, as previously mentioned, higher concentrations of BB0305 showed much greater variability in nanoparticle formation.

[0109] histological study A formulation of BB0305 containing a "spike" of 1% (w / w) FITC-conjugated Nanocin™ (a nanoparticle-based delivery platform composed of PHMB, commercially available from Tecrea Ltd, The London Bioscience Innovation Centre, 2 Royal College Street, London, NW1 0NH, UK) was made at an equivalent concentration of 0.1 mg / ml terbinafine. The labeled BB0305 was used in nail immersion experiments as described above. The washed and dried nails were then sent for histological analysis. Frozen cryosections of the nails were subjected to histology and fluorescence microscopy.

[0110] Exemplary images of histological studies using FITC-labeled BB0305 are shown in Figures 6A and 6B. Consistent with adhesion of BB0305 to the nail surface, strong fluorescence was observed around the nail margin. In addition, staining was observed penetrating from the surface into the nail. Although the level of staining varied, fluorescence could be detected deep within the nail structure itself (particularly as shown in Figure 6A).

[0111] Although this data strongly suggests that BB0305 nanoparticles penetrate the human nail, it was necessary to exclude the possibility that the observed staining was merely due to free FITC-Nanocin™. Therefore, we decided to proceed from these histological experiments and use Franz cells to directly measure drug transport across human nail samples.

[0112] Franz Cell Nail Penetration Study Nail clippings were immersed in water overnight at 30°C and briefly dried. Disc biopsies were taken from the clippings using a 3 mm diameter punch. Each nail disc was placed into a Franz cell, and the upper chamber of the cell was attached. 40 μl of the following formulations was added to the upper chamber: 0.3 mg / ml PHMB + 0.1 mg / ml terbinafine, or 10 mg / ml terbinafine. The lower collection chamber of the Franz cell was filled with water (approximately 600 μl), and the hole at the bottom of the sample chamber was also filled with ddH2O to prevent bubbles from forming under the nail. The upper sample chamber was carefully placed into the collection chamber, taking care not to introduce air bubbles. At this point, excess liquid from the collection chamber was drained to bring the final volume of liquid in the lower chamber to 500 μl. Parafilm® was used to wrap the joint between the upper and lower chambers to prevent liquid evaporation.

[0113] For single-dose (continuous exposure) experiments, 40 μl of the relevant test sample (BB0305 or terbinafine control) was added to the upper sample chamber using a fine pipette tip, avoiding the introduction of air bubbles at the nail / liquid interface. The upper chamber was sealed to limit evaporation. For multiple-dose experiments, 5 μl of sample was added daily for 7 days directly onto the nail in the upper sample chamber using a fine pipette tip, avoiding the introduction of air bubbles at the nail / liquid interface. The chamber was left open to allow the sample to evaporate. The Franz cells were incubated at 32°C in a humidified incubator with 0.5% (v / v) CO2.

[0114] After incubation of the Franz cell, the sample chamber and collar assembly were carefully removed, and all liquid was removed from the lower collection chamber and the hole at the bottom of the collar. After inverting the sample chamber and collar assembly, the underside of the nail was gently washed with 5 x 20 μl of ethanol to remove any drug bound to the underside of the nail. The combined ethanol washes were retained for analysis (total volume 100 μl). This wash was intended to capture any terbinafine that may have passed through the nail. Terbinafine found in either the lower collection chamber or the ethanol washes of the underside of the nail represented drug that had passed through the nail.

[0115] Nail discs from the Franz cells were also analyzed for the presence of terbinafine as follows: The remaining test sample was removed from the upper sample chamber and discarded, and the sample chamber was washed five times with 100 μl of ddH2O, discarding each wash to remove any residual test solution remaining in the sample chamber. The sample chamber and collar were then disassembled, and the nail sample was removed. The nail was washed by immersing it in a large volume of ddH2O, dried with clean tissue, and weighed. The weighed nail was then dissolved in 200 μl of 5 M NaOH at 37°C for 1 hour. After dissolution, 200 μl of methanol was added to the sample to ensure that all terbinafine in the sample remained in solution.

[0116] Figures 7-9B summarize data from Franz cell analysis of drug transport across human nail samples. Only data from the lysed nail samples and ethanol washes of the underside of the nail are provided, as observations were most consistent across samples. However, terbinafine was consistently detectable in the lower chamber of nails treated with BB0305, sometimes at very high levels (>0.6 μg / ml). This analysis is believed to represent a conservative view of the amount of terbinafine that crossed the nail in BB0305-treated samples.

[0117] Single-dose (constant exposure) experiment A 40 μl solution of BB0305 (equivalent to 0.1 mg / ml terbinafine) or terbinafine (0.1 mg / ml) in 30% (v / v) ethanol was added to the sample chamber of a Franz cell containing a healthy human nail sample. The cell was then incubated at 32°C for 7 days. The sample remained in contact with the upper surface of the nail throughout each experiment. After 7 days, samples (ethanol washes) from the underside of the nail were collected and analyzed by LC-MS / MS. Day 7 nail samples were washed and lysed with 5 M NaOH as previously described. All collected samples were analyzed for the presence of terbinafine using high-performance liquid chromatography with tandem mass spectrometry (LC-MS / MS) on a Waters Acquity I-Class UPLC chromatography system coupled to a Waters Xevo TQ-S mass spectrometer. Terbinafine levels were quantified against drug standards. The limit of detection for these analyses was 0.1 ng / ml.

[0118] As shown in Figures 7 and 8, samples treated with BB0305 consistently demonstrated penetration of terbinafine into healthy human nail samples. As early as day 1 of incubation, terbinafine was detectable in both the collection chamber solution and ethanol washes from the underside of the nail. Analysis of ethanol washes from the underside of nails treated with BB0305 for 7 days demonstrated strong drug delivery through the nail by BB0305 (shown in Figure 7). The amount delivered varied between samples, likely due to natural variability in nail samples, but in all cases was predicted to be greater than required to achieve a bactericidal dose.

[0119] In contrast, terbinafine solution did not penetrate the nail, and in all experiments using a drug concentration equivalent to BB0305 (0.1 mg / ml), the amount of terbinafine that penetrated the nail was below the detection limit (<0.1 ng / ml) by LC-MS / MS (as shown in Figure 7). By assuming that terbinafine penetrated to a concentration of 0.1 ng / ml, statistical tests could be applied to the data to demonstrate that the BB0305 results were significantly different from those of the plain terbinafine solution. The p-value of 0.04 calculated in this analysis is an underestimate of significance because we assumed the highest possible concentration of terbinafine in the plain terbinafine-treated samples.

[0120] The amount of terbinafine in the dissolved nail samples from the Franz cells was also determined on day 7 (as shown in Figure 8). This represented the amount of drug adhered to the top surface of the nail (not washed off before dissolution with 5M NaOH), combined with the drug in the nail itself, i.e., drug that had penetrated the nail but not reached the other side. Similar to the nail soak experiment (Figure 5), significantly higher amounts of terbinafine were found to be bound to nails treated with BB0305 compared to terbinafine alone (median difference approximately 2-fold, p=0.02). This is also consistent with the idea that BB0305 enhances the delivery of terbinafine into (and through) the nail.

[0121] Multiple-dose experiments In the single-dose experiment, the test solution was in constant contact with the upper surface of the nail throughout the entire incubation period. This does not necessarily reflect the reality of patient application, where the drug is applied daily to the infected nail and then allowed to dry. Therefore, to mimic this situation, we performed an experiment in which 5 μl of BB0305 was added daily to the nail in a Franz cell. This small amount was sufficient to cover the surface of the nail disc but evaporated before the next addition, more closely mimicking a patient applying BB0305 as a daily topical treatment. Samples from ethanol washes of the underside of the nail and the nail itself were collected and analyzed for the presence of terbinafine by LC-MS / MS as previously described.

[0122] In the multiple-dose experiment, significant amounts of terbinafine were detected bound to the nail itself (as shown in Figures 9A and 9B). This was not significantly different from the levels observed in the single-dose (constant exposure) experiment with BB0305 (shown in Figure 8) and was still higher than the terbinafine control from the single-dose experiment. Significant amounts of terbinafine were also detected in ethanol washes from the underside of the nail, indicating that the drug also crossed the nail in this experiment. Compared to the single-dose (constant exposure) experiment, the levels of drug delivered through the nail were much lower in the multiple-dose experiment. This is consistent with the idea that longer treatment with BB0305 increases the delivery of terbinafine through the nail.

[0123] Trichophyton mentagrophyte antifungal assay Previous experiments clearly demonstrated that BB0305 delivers terbinafine through the nail, but it was necessary to demonstrate that penetration of the drug through the nail did not result in chemical modification and loss of efficacy.Antifungal assays using T. mentagrophytes were performed.

[0124] T. mentagrophytes is an experimental fungal species related to the major pathogens associated with onychomycosis (see, e.g., Wade Foster et al., J. American Acad. Dermatology. 2004. 50(5). pp748-752), and efficacy against this species is expected to translate to efficacy against pathogenic tinea species such as T. rubum (Table 1 below).

[0125] [Table 4]

[0126] A single colony of T. mentagrophyte was picked from a stock plate and grown in 5 ml of YEPD (yeast extract, peptone, dextrose) medium at 30°C for 48 hours. A sterile swab was dipped into the resulting culture and used to spread a lawn of T. mentagrophyte on a YEPD agar plate supplemented with chloramphenicol (50 μg / ml). Chloramphenicol was included because samples from Franz cells were not sterile and bacterial growth was observed on plain YEPD plates. A 10 mm sterile paper disk was dipped into the test solution, excess liquid was removed, and the disk was placed on the lawn of T. mentagrophyte. The plate was inverted and incubated at 30°C for 5 days.

[0127] The first experiment conducted was to establish the approximate MIC (minimum inhibitor concentration) of terbinafine against T. mentagrophytes in a paper disc assay. To do this, a 1:10 dilution series of terbinafine.HCl in ddH2O was generated, ranging from 60 μg / ml to 0.06 μg / ml. 10 mm sterile paper discs were then immersed in the various dilutions and placed on T. mentagrophytes lawns. After 5 days of incubation, a zone of clearance was observed around the disc at terbinafine concentrations that had antifungal activity against this species (as shown in Figure 10). The MIC of terbinafine in this assay was 0.6 μg / ml; below this concentration, no clear zone of clearance was observed. It was noted that the MIC in this assay was over 100-fold higher than that previously reported for terbinafine against T. mentagrophytes (6 ng / ml) (see Table 1 above). The reported figures were certainly derived from the liquid MIC assay, which is known to be more sensitive, making the paper disc assay a much more rigorous test of drug potency.

[0128] This assay was also used to address the question of whether terbinafine passing through the nail of a sample treated with BB0305 still retained its antifungal efficacy. To do this, a T. mentagrophyte assay was performed using a sample of the aqueous phase from one of the Franz cell experiments, which quantitative LC-MS / MS analysis showed to contain greater than 0.6 μg / ml of terbinafine (Figures 11A-11B). Consistent with the MIC experiment and the quantitative MS results for this sample, a clear zone of clearance was observed with BB0305, while no effect was observed in the terbinafine control sample. Thus, terbinafine passing through healthy human nails treated with BB0305 retained its efficacy and was still able to kill T. mentagrophytes.

[0129] Potential efficacy of BB0305 in onychomycosis The goal of BB0305 was to compare the performance of oral terbinafine with a topical formulation of the drug that would lack the safety issues associated with systemic drug exposure. Compared with terbinafine solution, BB0305 was shown to significantly enhance drug delivery through healthy human nails. A key question was whether the dose achieved by BB0305 administration would be predicted to be effective in treating onychomycosis. To address this question, the terbinafine concentrations observed in Franz cell experiments were compared with those reported in the nails of patients treated with oral terbinafine (Leyden, J. Am. Acad. Dermatol. 1998:38:S42-7).

[0130] After oral administration, terbinafine reaches a concentration of 0.1 μg / g in the nail after 7 days of treatment, rising to approximately 0.25 μg / g after 3 weeks and 0.55 μg / g after 18 months (Leyden, 1998). All of these levels are higher than the MICs for a range of major fungal species associated with onychomycosis (Table 1), thus illustrating the drug's efficacy in treating fungal nail infections in these patients.

[0131] BB0305 appears to significantly exceed this level in dissolved nails (Figures 8 and 9A-9B), achieving a median concentration equivalent to approximately 1 mg / g of drug in the nail after 7 days (10,000-fold higher than oral administration). However, although terbinafine alone also produced significant, albeit lower, levels of drug bound to dissolved nails (median concentration of approximately 0.5 mg / g), studies with topical terbinafine (at doses much higher than those used in these experiments) failed to demonstrate efficacy in treating onychomycosis (Elewski et al., Journal of the European Academy of Dermatology and Venereology. 2013, 27(3), pp. 287-294).

[0132] Although a significant amount of drug was found to be bound to the nails treated with the terbinafine solution, no significant amount of terbinafine was measured to pass through the nail in any of the samples (Figure 7). Therefore, we concluded that in these samples, the majority of the drug adheres to the upper surface of the nail or does not penetrate very far into the tissue.

[0133] In contrast to terbinafine-treated samples, terbinafine was always detected on the underside of BB0305-treated nails, indicating that the drug must have entered and passed through the interior of the nail. Thus, measurements of terbinafine in dissolved nails from BB0305-treated samples represent not only the drug bound to the upper surface, but also the drug present throughout the depth of the tissue.

[0134] It is highly likely that the BB0305-treated nails established an asymmetric distribution of the drug, with greater concentrations on the upper (treated) surface and the lowest drug concentrations found toward the bottom of the nail. Therefore, we estimated the concentration of terbinafine in the lower portion of the nail, which is believed to be the lowest concentration of drug in the sample. To do this, we assumed that the level of drug found on the underside of the nail (in the ethanol wash) was equal to the concentration in the nail in the nail disc immediately above it. Although a 3 mm diameter disc of nail was used in the Franz cell experiment, only a 1.5 mm diameter circle of nail came into contact with the solution in the upper and lower chambers (the remainder of the nail formed a seal with the chamber itself). This suggests that terbinafine in the ethanol wash of the underside of the nail was present at approximately 1.8 mm diameter. 2 This means that the concentration is from the surface area of ​​the nail. To calculate the approximate concentration in the lower part of the nail, it was assumed that this part of the nail has a depth of 0.1 mm. Since the nail as a whole is about 0.5 mm thick, this corresponds to about one-fifth of the entire nail disc. Therefore, the volume of the lower part of the nail disc is 0.18 mm. 3 which corresponds to 0.18 μl. To calculate the concentration of terbinafine in the lower part of the nail, it was assumed that this volume of nail contained the same amount of terbinafine as found in the ethanol wash.

[0135] The median concentration of terbinafine found on the underside of the nail in the multiple-dose experiment was 0.4 ng / ml (Figures 9A-9B), corresponding to 0.04 ng of total terbinafine in the sample. From this, the concentration of terbinafine in the lowermost part of the nail was estimated to be 220 ng / ml (0.04 ng / 0.18 μl). Finally, because the density of healthy human nails is 1.34 g / ml (Baraldi et al., 2015, Pharm. Res. 32(5), 1626-33), the concentration of terbinafine in the lowermost part of the nail is approximately equal to 0.165 μg / g (0.22 μg / ml / 1.34 g / ml).

[0136] This calculation shows that BB0305 in the multiple-dose study delivered a higher amount of terbinafine to the lower nail than the concentration achieved by oral administration after 7 days (0.165 μg / g compared to 0.1 μg / g). This drug level is two to three times higher than the level required to kill the least susceptible fungal species associated with onychomycosis (>0.06 μg / ml, see Table 1). Concentrations are expected to be much higher in areas of the nail closer to the treated surface. These figures are based on the most conservative data from the multiple-dose study. For the single-dose study, the median terbinafine concentration found in the ethanol washes was 185 ng / ml (Figure 7), and the predicted lower nail drug concentration was 8 μg / ml, significantly exceeding the concentration achieved by oral administration and required for antifungal efficacy.

[0137] In summary, topical application of BB0305 for 7 days promotes significantly greater binding of terbinafine to healthy human nails than simple terbinafine solution. Furthermore, BB0305 allows terbinafine to penetrate the entire nail, indicating that the increased intraungual levels of this drug are at least partially due to enhanced drug penetration into the tissue. Even the most distal nail region from application of BB0305 is predicted to achieve drug concentrations that exceed those produced by an equivalent oral dose. This level is greater than the MIC for related fungal species and is therefore likely to be effective in treating onychomycosis.

[0138] Oral terbinafine is currently the "gold standard" for the treatment of onychomycosis, with the shortest treatment time and the highest cure rate (>80% cure after 3-6 months of medication). However, its use in treating the disease is limited by its safety profile and the significant drug-drug interactions of terbinafine. Many of these problems are almost certainly due to oral administration (e.g., hepatotoxicity, CNS effects) and subsequent high systemic drug exposure. Other topical onychomycosis treatments require long-term treatment regimens (up to 18 months of treatment), have low cure rates (20-40%), and have high disease recurrence rates (>50%) (Halmy, KJ Am. Acad. Dermatol. 2005. 52(3):126-126; Scher et al., J Am Ac Dermatol. 2007; 56(6):939-944). The production of an effective topical formulation of terbinafine is a very attractive approach to the treatment of onychomycosis because it employs a drug with the best proven clinical efficacy and eliminates the safety issues associated with systemic exposure. This has proven difficult to achieve, and many past attempts with topical terbinafine solutions have failed to demonstrate significant efficacy in the treatment of onychomycosis.

[0139] As mentioned above, the amount of terbinafine present in BB0305 for topical application is believed to be much lower than that required for current oral administration. Current systemic treatment typically uses 250 mg of oral terbinafine per day for 7 days. After daily topical application of a small amount of BB0305 to nail samples for 7 days (mimicking daily application in patients), higher levels of terbinafine were achieved in the nail than reported for oral administration. The drug levels found in the nail are much higher than would be required to demonstrate efficacy against all relevant fungal species associated with onychomycosis (Table 1). Given the context, these experiments suggest that the average nail (100 mm 2 The dose of BB0305 that would have been required to treat TB would have been approximately 200 μg per week, or 8750 times lower, compared with 1.75 g of oral terbinafine.

[0140] Finally, healthy human nails are a much more rigorous drug penetration test. A recent publication by Baraldi et al. (Baraldi et al., 2015) showed that in onychomycosis, nails are thicker but their integrity is severely compromised, meaning that aqueous solutions penetrate much more readily (3–4 times). Therefore, it is expected that BB0305 will exhibit even better drug penetration properties in diseased tissue.

[0141] Comparison of BB0305 in 20% (v / v) ethanol vs. 30% (v / v) ethanol All previous experiments with BB0305 were performed in a solution of 30% (v / v) ethanol. Initial formulation studies showed that 30% (v / v) ethanol produced the greatest number of BB0305 nanoparticles, whereas experiments in 10% (v / v) or lower ethanol solutions showed a significant decrease in particle count. While 30% (v / v) ethanol is an acceptable solution for treating topical fungal infections, different % (v / v) ethanol was evaluated to determine whether efficacy was maintained at lower ethanol contents. Therefore, we decided to investigate a formulation of BB0305 in 20% (v / v) ethanol.

[0142] A formulation of BB0305 was made as described above, but using 20% ​​(v / v) ethanol instead of 30% (v / v) ethanol. Analysis with a NanoSight LM10 revealed no detectable differences in either BB0305 particle number or particle distribution in the 20% (v / v) formulation compared to the 30% (v / v) ethanol formulation. Therefore, several multi-dose Franz cell experiments were performed using a BB0305 formulation in 20% (v / v) ethanol, as this best mimics the type of daily topical administration likely used by patients and is therefore most meaningful for modeling the efficacy of drug treatment in onychomycosis.

[0143] The amount of terbinafine found in ethanol washes from the underside of nails treated with 5 μl of BB0305 in 20% (v / v) ethanol daily for 1 week was analyzed by LC-MS / MS as described in the text (as shown in Figure 12). These showed consistent levels of terbinafine passing through the nails, with a mean value of 0.5 ng / ml in the washes. The data showed a trend toward slightly higher amounts of terbinafine passing through nails treated with BB0305 in 20% (v / v) ethanol, suggesting that BB0305 in 20% (v / v) is more effective at delivering the drug through the nail. Consistent with this, the amount of terbinafine in dissolved nails treated with BB0305 in 20% (v / v) ethanol was three-fold higher than those treated with BB0305 in 30% (v / v) ethanol (as shown in Figure 13).

[0144] Taken together, these results demonstrate that the use of a formulation of BB0305 in 20% (v / v) ethanol further enhances terbinafine delivery into and through the human nail in Franz cell multiple-dose (daily addition) experiments. A much larger amount of drug was found bound to the nail, and the amount of terbinafine that penetrated the nail was also higher. Calculations indicated that the median drug concentration in the lower portion of the nail treated with this BB0305 formulation was 0.21 μg / g, double that achieved in the nail after oral administration on day 7 and far exceeding that required to kill the fungal species associated with onychomycosis. This result is consistent with the observations of Baraldi et al. (Baraldi et al., 2015) that compounds in aqueous solution have a higher level of penetration into both healthy and diseased nails compared to compounds in 50% (v / v) ethanol solution.

[0145] In summary, reducing the ethanol concentration in solutions of BB0305 from 30% to 20% (v / v) has no detectable effect on nanoparticle formation, but interestingly, formulation of BB0305 in 20% (v / v) ethanol shows improved terbinafine delivery properties into and through healthy human nails in Franz cell experiments that mimic daily application of the drug in the treatment of onychomycosis.

[0146] Onychomycosis drug formulations In light of the above experiments, it is envisioned that the following formulations would be effective as topical medications for onychomycosis.

[0147] [Table 5]

[0148] Other formulations may also provide effective topical medication.

[0149] [Table 6]

[0150] [Table 7]

[0151] [Table 8]

[0152] [Table 9]

[0153] It will be readily apparent to those skilled in the art that commonly used pharmaceutical ingredients, including buffers, excipients, binders, oils, water, emulsifiers, glycerin, antioxidants, preservatives, and flavorings, as well as urea, may be used with the above Formulations A through E. Such ingredients may be used to partially replace water and allow the drug to be formulated into a suitable topical form such as a cream, ointment, or spray.

[0154] A formulation according to the present invention was prepared according to formula F below and designated BB2603.

[0155] [Table 10]

[0156] A formulation of Formula F was placed in a spray bottle. It was then tested by periodically spraying the formulation onto the toes of patients suffering from onychomycosis (and possibly tinea pedis) over a period of 1-2 weeks. This treatment proved successful, successfully and quickly curing patients suffering from onychomycosis (and tinea pedis) without subsequent recurrence.

[0157] Microneedle Patch Transdermal patches have long been used to administer small, lipophilic drugs that can be readily absorbed through the skin. This noninvasive delivery route is advantageous for administering many drugs that are not amenable to oral delivery because it allows for direct absorption of the drug into the systemic circulation, bypassing both the gastrointestinal tract and the hepatic portal system, which can dramatically reduce the bioavailability of many drugs. Transdermal delivery also overcomes many of the challenges associated with subcutaneous injections by significantly reducing patient discomfort, needle anxiety, the risk of needlestick injuries for the administering personnel, and issues surrounding sharps disposal.

[0158] Despite these many advantages, transdermal drug delivery is limited to classes of molecules compatible with absorption through the skin. Delivery of small molecule salts and therapeutic proteins is typically not feasible using traditional transdermal delivery because the skin provides an effective protective barrier against these molecules, even in the presence of absorption-enhancing excipients. However, using microneedle technology, nanoparticles containing antifungal agents can be delivered directly to the epidermis, dermis, and nail matrix (where the nail meets the skin at the cuticle). By delivering the compositions of the present invention in this manner, the nanoparticles enter the nail matrix and capillary system, delivering the antifungal nanoparticle composition to the nail bed, under the hard nail plate, and into the fungus. In this way, potent antifungal agents can be delivered directly to the site of action, thereby shortening treatment time and increasing efficacy.

[0159] 14 and 15 show diagrams of a finger 10, where a microneedle patch (shown in FIG. 16) may be applied within the dotted treatment area 12 of the finger. The treatment area 12 is formed by the dermis behind the nail 14, as well as the nail matrix (cuticle) 16 where the nail meets the skin. The nail root 18 is located in the area below the dermis behind the nail, and therefore may be effectively treated by applying a microneedle patch to deliver the compositions of the present invention. Of course, microneedle patches may be used on toenails in addition to fingernails.

[0160] FIG. 16 shows a diagram of a microneedle patch that can be used to administer the compositions of the present invention to individuals suffering from fungal nail infections. The microneedle patch 20 is formed of a flexible web material 22 with an adhesive 24 applied to the underside. An array 26 of downwardly extending microneedles having multiple points 30 is centrally located on the underside of the flexible web. The points can be formed as needles with conduits connected to a reservoir 28 containing the composition, or the points can simply be coated with the composition. In an alternative configuration, the reservoir 28 can release the composition through holes located around the microneedle array so that the composition can continuously coat the points of the array over a predetermined time frame. Several microneedle patches are currently available, and it will be apparent to one of skill in the art that the compositions of the present invention can be adapted for use with various microneedle patches.

[0161] Microneedles can be less than 2 mm in length, preferably about 250 μm, to be inserted into the skin with minimal patient discomfort, and the small hole created minimizes the risk of post-injection infection, bleeding, or inadvertent IV injection with intradermal administration. Microneedles also reduce risk to the injector, as skin punctures are unlikely with these small protrusions.

[0162] It is envisioned that the microneedle patch can be used for a single treatment, where the patient simply removes the patch from the packaging and applies it to the appropriate part of the finger or toe for a predetermined period of time. Alternatively, the microneedle patch can be sold in combination with a composition, and the patient can coat a certain amount of the composition onto the surface of the microneedles and apply the patch to the body in a prescribed manner. The patch can also have markings on its exterior to help the patient or doctor properly align the microneedles to the correct position on the finger or toe to be treated.

[0163] The above embodiments are not intended to limit the scope of protection provided by the claims, but rather to illustrate examples of how the invention may be practiced.

Claims

1. 1. A composition for use in the treatment of a fungal infection, comprising polyhexamethylene biguanide (PHMB) and terbinafine or a salt thereof, said composition being in nanoparticulate form, said composition comprising: a) the ratio of terbinafine or a salt thereof to polyhexamethylene biguanide (PHMB) is in the range of 1:2.5 to 1:3.5, and the terbinafine or a salt thereof is in an amount in the range of 0.1 to 10 mg / mL; b) A composition comprising an amount of alcohol in the range of 20% to 30% (v / v), said alcohol being ethanol, and further comprising water.

2. The composition of claim 1 , wherein the composition is a topical composition.

3. 3. The composition of claim 1, wherein the water is present in an amount in the range of 70% to 80% (v / v).

4. 1. A composition in nanoparticle form for use in the treatment of fungal infections, comprising: (a) terbinafine or a salt thereof present in an amount in the range of 0.01% w / w to 1% w / w; (b) a polymer comprising polyhexamethylene biguanide (PHMB), wherein the polyhexamethylene biguanide (PHMB) is present in an amount ranging from 0.015% w / w to 3% w / w, and wherein the terbinafine or a salt thereof and the polyhexamethylene biguanide (PHMB) are present in a ratio ranging from about 1:2.5 to about 1:3.5; (c) ethanol in an amount ranging from 20% to 30% (v / v); (d) up to 90% w / w water; A composition comprising:

5. (a) 0.1% w / w of terbinafine or a salt thereof; (b) 0.3% w / w of a polymer; (c) 20% w / w ethanol; (d) up to 79.6% w / w water; The composition of claim 4 comprising:

6. The composition of any one of claims 1 to 3, wherein the ratio of terbinafine or a salt thereof to polymer is 1:

3.

7. The composition according to any one of claims 1 to 6, wherein the nanoparticles comprise two species of particles of different sizes.

8. 8. The composition of claim 7, wherein the species include a first species in the range of 0.5 to 5 nm and a second species in the range of 50 to 350 nm.

9. The composition of any one of claims 1 to 8, wherein the fungal infection comprises a fungal nail infection or a fungal skin infection.

10. 10. The composition of claim 9, wherein the fungal nail or skin infection comprises onychomycosis and / or athlete's foot, or a dermatophyte infection and / or a yeast infection.

11. 1. A method of producing a composition for use in treating fungal infections, comprising the steps of: mixing terbinafine or a salt thereof in an amount ranging from 0.1 to 10 mg / ml with a polymer capable of forming nanoparticles, the polymer being polyhexamethylene biguanide (PHMB), in a ratio of 1:2.5 to 1:3.5 under conditions suitable to allow the formation of nanoparticles; and adding ethanol in an amount ranging from 20% to 30% (v / v), wherein water is present in an amount ranging from 70% to 80% (v / v).

12. The method of claim 11 , wherein the method is for the production of a topical composition.

13. 13. The method of claim 11 or 12, wherein terbinafine or a salt thereof is mixed with the polymer in a ratio of 1:

3.

14. The method according to any one of claims 11 to 13, wherein the nanoparticles are formed of two species of particles with different diameters.

15. 15. The method of claim 14, wherein the species include a first species in the range of 0.5 to 5 nm and a second species in the range of 50 to 350 nm.

16. The method of any one of claims 11 to 15, wherein the fungal infection comprises a fungal nail infection or a fungal skin infection.

17. 17. The method of claim 16, wherein the fungal nail or skin infection comprises athlete's foot or dermatophyte infection and / or yeast infection.

18. The method according to any one of claims 11 to 17, wherein the method is for the production of a topical composition.

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