EP3996748A2

EP3996748A2 - Smart temperature-sensitive hydrogels with antifungal property that perform controlled drug release

Info

Publication number: EP3996748A2
Application number: EP20836170.9A
Authority: EP
Inventors: Bahar KANCI BOZOGLAN; Sibel TUNC; Osman Duman
Original assignee: Akdeniz Univ; Akdeniz Universitesi
Current assignee: Akdeniz Univ; Akdeniz Universitesi
Priority date: 2019-07-09
Filing date: 2020-07-07
Publication date: 2022-05-18
Also published as: WO2021006845A2; TR201910214A2; WO2021006845A3; EP3996748A4

Abstract

The present invention relates to temperature-sensitive smart hydrogels that feature antifungal property and perform controlled drug release. Smart hydrogels were developed to be used in the treatment of nail fungus. The inventive hydrogel formula comprises at least one natural polymer (polysaccharide and/or protein) additive, at least one inorganic or organic additive, and an active pharmaceutical ingredient with antifungal property. The antifungal drug in hydrogel formulation is released in a controlled manner, and this not only shortens the treatment period but also reduces the amount of the drug administered since the necessity for regularly administering drugs to the fungal infection area is eliminated.

Description

SMART TEMPERATURE-SENSITIVE HYDROGELS WITH ANTIFUNGAL PROPERTY THAT PERFORM CONTROLLED DRUG RELEASE Technical Field of the Invention

The present invention relates to temperature-sensitive smart hydrogels that have antifungal property and perform controlled drug release. Smart hydrogels were developed to be used in the treatment of nail fungus. The inventive hydrogel formula comprises at least one natural polymer (polysaccharide and/or protein) additive, at least one inorganic or organic additive, and an active pharmaceutical ingredient with antifungal property. The antifungal drug in hydrogel formulation is released in a controlled manner, and this not only shortens the treatment period but also reduces the amount of the drug administered since the necessity for regularly administering drugs to the fungal infection area is eliminated.

State of the Art (Prior Art)

Nail fungus is a type of nail infection caused by dermatophytes, yeast, and molds. Treatment of nail fungus involves removing the infected nail through chemical or surgical interventions, systemic or topical drug use, or a combination of these [1]. Oral and topical treatment methods are usually preferred for the treatment of the disease. Available topical treatment methods include lacquer, spray and cream administrations, and commercially available topical products mainly comprise of various chemical agents such as; methyl vinyl ether, maleic acid monobutyl ester copolymer, ethyl acetate, and 2-propanol.

Another method that is frequently implemented for the treatment of the disease is systemic drug administration through the oral route. However, recurrence of the disease and being unable to administer a full treatment are among the frequently encountered cases in treatment methods implemented via the oral route. Moreover, oral treatment is not suitable for many patients due to potential adverse effects [2]. In a study conducted by Korting et al., griseofulvin fungicide was administered to patients at a dose of 990 mg for a duration of 78 weeks. Only 6% of patients were reported to make a full recovery at the end of the treatment period, and a number of patients with nail fungus failed to complete the treatment due to adverse effects of the drug. It was further reported that the disease recurred in a number of patients after the treatment period was completed [3].

In the state of the art, nail lacquers prepared with ciclopirox and amorolfine active ingredients were also reported to be successful in practice in the treatment of nail fungus. These nail lacquers are usually prepared with 2-n-nonyl-1 ,3-dioxolan or similar water- insoluble agents with film-forming capabilities, plasticizers, and a volatile solvent. However, patients who were administered ciclopirox lacquer were observed to suffer from adverse effects including redness, and a rash around nail folds, nail malformation, irritation, ingrown toenails, and discoloration [4, 5].

The duration of treatment administered with topical nail lacquers containing amorolfine active ingredient is approximately 6 months for hand nails, while for toenails this period may last for approximately 9-12 months. Prolonged treatment periods and complaints such as pruritus, pain, and stinging around the nail bed are among the disadvantages of nail lacquer products containing amorolfine [5].

In the state of the art, the patent application numbered US 2003/0176306 A1 discloses a solution that cleans mold from surfaces and comprises chitosan, a chloride source, a surfactant, and water. In said patent application, it is stated that the inventive product inhibits the development of Aspergillus niger strain up to 8 weeks. Chitosan is included in the solution in the form of chitosan salt, and mainly chitosan glutamate or chitosan chloride salt is used in the invention mentioned above. The formulation contains 0.001 % - 1.0% chitosan salt by weight, preferably 0.005% - 0.5% chitosan salt by weight. WO 2010/109418 A1 which is another patent application in the state of the art, relates to a chitosan-based biopolymer that cures fungal skin infections. The aforementioned application discloses a cream comprising; chitosan, active pharmacological compound, emulsifying compounds, beeswax, acid, preservative agents, buffering agents, antioxidants, chelating agents, and moisturizers. Treatments administered via oral route in the state of the art take prolonged periods of time and force patients to suffer various adverse effects including headaches, gastrointestinal disorders (diarrhea and/or dyspepsia), rash, high liver enzyme values, and drug interactions. Topical cream administration, on the other hand, does not provide any practicality of use for patients. Even daily routine activities such as washing hands, putting a pair of socks on or fundamental human movements become a challenge in case there is the cream on an infected nail. Topical products require frequent administration in order to ensure effective treatment, this, however, affects a patient's daily life negatively. In brief, treatment options available in the state of the art offer low success rate, difficult and prolonged treatment periods.

The inadequacy of available solutions in this regard necessitated making an improvement in the relevant technical field. Hence, the present invention relates to a smart hydrogel formulation with antifungal property, as well as the preparation method thereof, that is developed to be used in the treatment of nail fungus, and that eliminates the disadvantages present in the state of the art.

Brief Description and Objects of the Invention

The present invention discloses a smart hydrogel formulation with antifungal property, wherein the formulation comprises of at least one natural polymer (polysaccharide and/or protein), at least one inorganic and organic additive, and an active pharmaceutical ingredient with antifungal property.

An object of the present invention is to develop a biocompatible and biodegradable hydrogel formula for the treatment of nail fungus.

Another object of the present invention is to provide a hydrogel with antifungal property that does not show any toxic effects, thereby preventing the patient from suffering any adverse effects throughout the treatment period of nail fungus.

Another object of the present invention is to develop a hydrogel formula with antifungal property, that maintains its liquid form under room conditions, but transforms into gel form once it reaches to skin temperature value (32 °C) when it is administered to nail surface. This particular characteristic of the inventive hydrogel formula provides ease of use for patients.

The inventive hydrogel formula also performs controlled drug release. This feature eliminates the necessity for regularly administering the drug to the fungal infection area, thereby shortening the treatment period and reducing the amount of drug administered.

Description of the Figures

Figure 1: illustrates the elastic modulus (G') and viscous modulus (G") graphs as a function of temperature for hydrogel sample without additive.

Figure 2: illustrates the elastic modulus (G') and viscous modulus (G") graphs as a function of temperature for hydrogel sample containing additive of 5%.

Figure 3: illustrates the SEM images of hydrogel systems containing additive of 0% and 5%.

Figure 4: illustrates the TGA graphs of hydrogel systems containing additive of 0% and 5%.

Figure 5: illustrates the DSC graphs of hydrogel systems containing additive of 0% and 5%.

Figure 6: illustrates the transmittance versus wavelength graphs of hydrogels containing additive of 0% and 5%.

Figure 7: illustrates the compression stress versus compression strain graphs of hydrogels containing additive of 0% and 5%.

Figure 8: illustrates the variation of released drug amount as a function of time from new prepared hydrogels including active drug and containing additive of 0% and

5%.

Figure 9: illustrates the variation of released drug amount as a function of time from hydrogels including antifungal drug and containing additive of 0% and 5% after hydrogels were stored at +4°C for 3 months. Figure 10: illustrates the variation of released drug amount as a function of time from hydrogels including antifungal drug and containing additive of 0% and 5% after hydrogels were stored at +4°C for 6 months. Detailed Description of the Invention

The present invention relates to temperature-sensitive smart hydrogels with antifungal property that perform controlled drug release and the preparation method thereof. The inventive smart hydrogel comprises chitosan, and apart from that, it contains; at least one natural polymer, at least one inorganic or organic additive, and at least one active pharmaceutical ingredient with antifungal effect.

As a natural polymer; chitosan, collagen, starch, gelatin, dextran, actine, agar, alginate, chitin, keratin, cellulose, guar gum, carrageenan, gellan gum, scleroglucan, cyclodextrin, xanthan gum, pectin, inulin, hyaluronic acid, glucomannan and/or hyaluronan and/or at least one derivative thereof or a combination thereof may be used in the present invention. As an inorganic or organic additive; kaolinite, halloysite, vemniculite, saponite, nontronite, disodium hydrogen phosphate (Na₂HPO₄), sodium bicarbonate (NaHCO₃), sodium dihydrogen phosphate (Na₂HPO₄), illite, montmorillonite, chlorite, attapulgite, sepiolite, bentonite, zeolite, fumed silica, starch, modified starch or talc and/or carbonate, b- glycerophosphate, benzoate, acetate, phosphate, malate, lactate, succinate, acrylate and at least one of sodium (Na) and/or potassium (K) and/or calcium (Ca) salts of sulfate or a combination thereof may be used in the present invention.

Any one of active pharmaceutical ingredient/ingredients and/or salts with antifungal property such as; fluconazole, itraconazole, griseofulvin, ketoconazole, clotrimazole, oxiconazole, miconazole, and econazole or a combination thereof may be used as an active pharmaceutical ingredient with antifungal property in the present invention.

Method for preparing the inventive hydrogels with antifungal property comprises the process steps of; i. preparing chitosan or chitosan salt solution in a range between 0.1 % - 8.0% by weight/volume (w/v) inside hydrochloric acid, acetic acid, succinic acid, sulfuric acid, oxalic acid or phosphoric acid or purified water within a range of 0.02 M - 2.0

M,

ii. preparing natural polymer solution/solutions in a range between 0.1 % - 10.0% (w/v) within inorganic or organic salt solution/solutions in a range between 0.2 M - 5.0 M, iii. mixing the solution prepared in the process step (i) and the solution/solutions prepared in the process step (ii) such that their ratio to one another is in a range between 10% - 90% by weight,

iv. adjusting the pH value of the mixture to a value in a range between 5 - 9 by adding acid, base or salt solution in a range between 0.01 M - 1.0 M,

V. preparing the solution containing at least one inorganic or organic additive within inorganic or organic salt solution/solutions in a range between 0.2 M - 5.0 M such that the total amount of additive/additives is in a range between 0.01 % - 5.0% (w/v), vi. mixing the solutions prepared in process step (iii) and process step (v) such that their ratio to one another (solution(v): solution(iii)) is at a maximum of 20% by weight,

Vii. preparing the solution of active pharmaceutical ingredient with antifungal effect in the water, acid, base or an organic solvent such that the amount of active pharmaceutical ingredient with the antifungal effect is in a range between 0.01 % - 5.0% (w/v),

Viii. mixing the solution of antifungal active pharmaceutical ingredient with the solution prepared in the process step (vi).

In an embodiment of the present invention, preparing the inventive hydrogels with antifungal property comprises the process steps of; i. preparing chitosan or chitosan salt solution in a range between 0.5% - 4.0% by weight/volume (w/v) inside hydrochloric acid, acetic acid, succinic acid, sulfuric acid, oxalic acid or phosphoric acid or purified water within a range of 0.05 M - 1.0

M, ii. preparing natural polymer solution/solutions in a range between 0.25% - 5.0% (w/v) within inorganic or organic salt solution/solutions in a range between 0.25 M - 2.0

M,

iii. mixing the solution prepared in the process step (i) and the solution/solutions prepared in the process step (ii) such that their ratio to one another is in a range between 15% - 75% by weight,

V. preparing the solution containing at least one inorganic or organic additive in inorganic or organic salt solution/solutions in a range between 0.25 M - 2.0 M such that the total amount of the additive or additives is in a range between 0.01 % - 5.0% (w/v),

Vi. mixing the solutions prepared in process step (iii) and process step (v) such that their ratio to one another (solution(v): solution(iii)) is at a maximum of 20% by weight,

Vii. Preparing the solution of active pharmaceutical ingredient with antifungal effect in the water, acid, base or an organic solvent such that the amount of active pharmaceutical ingredient with the antifungal effect is in a range between 0.1 % - 2.5% (w/v),

The acid used in the present invention is selected from; hydrochloric acid, acetic acid, succinic acid, sulfuric acid, oxalic acid, or phosphoric acid. The base used in the present invention is selected from; sodium hydroxide, ammonia, or sodium carbonate. As an organic solvent, the present invention comprises; acetone, acetonitrile, benzene, diethyl ether, dimethylformamide, dimethyl sulfoxide, ethyl alcohol, ethyl acetate, heptane, hexane, chloroform, xylene, petroleum ether, methyl alcohol, carbon tetrachloride or toluene. The inventive smart hydrogel is in liquid form under room conditions and transforms into gel form once its temperature reaches 32 °C which is the external skin temperature. Smart hydrogels are obtained in liquid form by means of the inventive method, and these smart hydrogels convert into gel form through body temperature once they are applied to the surface of the skin.

The inventive hydrogel comprises; chitosan at a rate of at least 15% and at least one natural polymer, one inorganic or organic additive at a rate of at least 3% and active pharmaceutical ingredient with antifungal property at a rate of at least 0.1 %.

Elastic modulus (G') and viscous modulus (G") values of the inventive hydrogel samples were obtained via rheologic analyses. Measuring operations were performed by gradually increasing the temperature from 20.0 °C to 60.0 °C. Gelling temperatures of hydrogel systems were determined from the results of rheological analysis, and corresponding graphs for smart hydrogels containing additive of 0% and 5% are illustrated in Figure 1 and Figure 2, respectively. Gelling temperature values observed in said graphs were determined to be in a range between 32.0 °C - 25.3 °C for systems that contain additive and for systems that do not.

Hydrogel samples were coated with a thin layer of gold/palladium in order to perform the Scanning Electron Microscopy (SEM) analysis of hydrogels, and SEM images were obtained thereafter. SEM images of smart hydrogels containing additive of 0% and 5% are shown in Figure 3. An examination of the aforementioned SEM images reveals that the inventive smart hydrogels have a porous structure. Moreover, adding any additives to the hydrogel matrix results in a significant reduction in the pore size within the structure.

Thermal gravimetric analysis (TGA) was performed at a temperature value in a range between 30 - 700°C and in nitrogen (N2) gas atmosphere. Degradation temperatures were determined to be 145 °C and 175 °C, respectively, according to the TGA results of hydrogel systems containing additive of 0% and 5% as illustrated in Figure 4. TGA results indicate that an increase of the additive within the matrix reduces the amount of percentage mass loss of the material. Glass transition temperature (T_g) values of hydrogels that do not contain additive (0%) and that contain additive of 5% were determined via the Differential Scanning Calorimetry (DSC) analysis. Endothermic peak shown in DSC graphs of hydrogels containing additive of 0% and 5% as shown in Figure 5 indicates the T_g values of hydrogels. T_g values of hydrogels containing additive of 0% and 5% were determined to be 63.7 °C and 76.8 °C, respectively. It should be noted that an increase in the amount of additive present in the hydrogel matrix also increases the T_g values.

Contact angles of hydrogels were measured and contact angle values for all smart hydrogels were determined to be less than 90°. This shows the fact that the inventive smart hydrogels have a hydrophilic structure.

Transmittance (%) values were measured at a wavelength range between 300 - 800 nm by using a UV-Vis spectrophotometry (Figure 6) in order to calculate the opacity (O) values of hydrogels, and accordingly, the opacity values of hydrogels were calculated by using the equation provided below.

O = AbS(600)/x

In the equation given above, AbS(eoo) denotes the sample's absorbance value at 600 nm, and x denotes the thickness of the sample in mm. Opacity values for hydrogel systems containing additive of 0% and %5 were calculated as 1.86±0.11 and 2.87±0.19, respectively. These values indicate that the presence of additive in the hydrogel matrix increases the opacity of the hydrogel and causes hydrogels to become slightly matted.

Cylindrical hydrogel samples with the same dimensions were prepared in order to perform the mechanical resistance tests of hydrogels with and without additives. Subsequently, the samples were subjected to a compression test with a velocity of 1 mm/min by using a load cell of 500 N. The compression test results did not reveal any physical deformation or breakage (fragmentation) on hydrogel samples. Hydrogel sample containing additive of 5% was observed to revert to its original shape by a rate of 61.5%, and this measurement for the hydrogel sample that does not contain any additives was determined to be 46.2% once the physical force was removed. This result shows that the hydrogel sample that contained additive managed to preserve its elasticity better against the force applied thereto when compared to the hydrogel sample that did not contain any additives. Pursuant thereto, the graphic illustrated in Figure 7 was obtained from the compression stress and compression strain values determined as a result of the compression tests conducted for the hydrogels containing 0% and 5% of the additive. Increasing the amount of additive put into the matrix also increases the compression stress values of hydrogels. Compression stress values of hydrogels containing additive of 0% and 5% were determined as 126.45±8.83 kPa and 266.99±6.60 kPa, respectively. Increasing the amount of additives put into the matrix also increases the compression stress values of hydrogels as stated earlier. This indicates the fact that the addition of additives increases the mechanical resistance of hydrogels.

Hydrogel samples containing active pharmaceutical ingredients were dried in a vacuum oven in order to examine the drug release activity of smart hydrogels. Dried hydrogel samples were placed into buffer solution at physiological pH and at 32 °C which is the external skin temperature and subjected to release tests by being agitated at 32 °C and 60 rpm via a temperature-controlled water bath with agitation. As illustrated in Figure 8, increasing the amount of additive in the hydrogel matrix significantly reduces the antifungal drug release. At the end of the testing period, percentage drug release amounts were determined as 70.33±1.74 for the system that did not contain additive and 52.89±0.21 for the system that contained additive of 5%. It was observed that putting additive into the hydrogel matrix allows for controlling the drug release amounts.

Hydrogel samples loaded with active pharmaceutical ingredients with antifungal property were kept at 4 °C for durations of 3 and 6 months in a light- and moisture-proof environment to be able to determine that whether hydrogels loaded with the active pharmaceutical ingredient with antifungal property can preserve the pharmaceutical ingredient contained therein or not. Amounts of drug released from hydrogels were measured via UV-Vis spectrophotometry at the end of preservation periods (Figure 9 and Figure 10). Percentage drug release amounts for systems containing additive of 0% and 5% were calculated as 66.90±0.90 and 51.5±0.66, respectively, at the end of the 3-month period. Whereas the percentage drug release amounts at the end of the 6-month period were determined as 64.76±0.21 and 51 55±1.02. Hydrogels preserved for 3 and 6 months showed no significant differences from one another in terms of the percentage of drug release amounts.

Lyophilized Trichophyton mentagrophytes strain was activated in order to test the antifungal property of hydrogels. Transmittance (%) value of inoculum solution was adjusted to be 70% at 520 nm by using a UV-Vis Spectrophotometry. The solution's spore count was measured with a hemocytometer and determined as 5.0x10⁶ spore/mL. The disk diffusion method was employed in order to observe the effect the hydrogels will produce against the fungi to reproduce in the medium. Inoculum solution of Trichophyton mentagrophytes fungus was cultured in the Saboroud medium. The hydrogel containing additive of 0%, hydrogel containing additive of 0% and active pharmaceutical ingredient with antifungal property, hydrogel containing additive of 5%, hydrogel containing additive of 5% and active pharmaceutical ingredient with antifungal property and control group samples were prepared and placed inside mediums, and inhibition diameters formed around the gels were measured at the end of the incubation period. Hydrogels that did not contain any active pharmaceutical ingredients did not form any inhibition zones. Whereas the inhibition zones formed by hydrogels that did contain additive of 0% and 5% and active pharmaceutical ingredient with antifungal property were measured as 42±2.65 mm and 42.67±1.5 mm, respectively. Antifungal activity test revealed the fact that hydrogels that contain additive of 0% and 5% and loaded with the active pharmaceutical ingredient with antifungal property are substantially effective against Trichophyton mentagrophytes species in the fungal genus.

REFERENCES

1) Ghannoum, M., and Isham, N. 2014. Fungal nail infections (onychomycosis): a never- ending story? FLOS Pathogens, 10 (6): e1004105 10.1371 /journal. ppat.1004105.

2) Thomas, J., Jacobson, G.A., Narkowicz, C.K., Peterson, G.M., Burnet, H., and Sharpe, C. 2010. Toenail onychomycosis: an important global disease burden. Journal of Clinical Pharmacy and Therapeutics, 35 (5): 497-519.

3) Korting, H.C., Schafer-Korting, M., Zienicke, H., Georgii, A., Ollert, M.W. 1993.

Treatment of tinea unguium with medium and high doses of ultramicrosize griseofulvin compared with that with itraconazole. Antimicrobial Agents and Chemotherapy, 37: 2064-2068.

4) Gupta, A.K., Schouten, J.R. and Lynch, L.E. 2005. Ciclopirox nail lacquer 8% for the treatment of onychomycosis: a Canadian perspective. Skin Therapy Letter, 10 (7): 1 -

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5) Shirwaikar, A. A., Thomas, T., Shirwaikar, A., Lobo, R. and Prabhu, K.S. 2008.

Treatment of onychomycosis: An update. Indian Journal of Pharmaceutical Sciences, 70 (6): 710-714.

Claims

1. Temperature-sensitive smart hydrogels that feature antifungal property and perform controlled drug release, characterized by comprising the process steps of; i. preparing chitosan or chitosan salt solution in a range between 0.1 % - 8.0% by weight/volume (w/v) inside hydrochloric acid, acetic acid, succinic acid, sulfuric acid, oxalic acid or phosphoric acid or purified water within a range of 0.02 M - 2.0 M,

preparing natural polymer solution/solutions in a range between 0.1 % - 10.0% (w/v) within inorganic or organic salt solution/solutions in a range between 0.2 M - 5.0 M,

iii. mixing the solution prepared in the process step (i) and the solution/solutions prepared in the process step (ii) such that their ratio to one another is in a range between 10% - 90% by weight,

V. preparing the solution containing at least one inorganic or organic additive within the inorganic or organic salt solution in a range between 0.2 M - 5.0 M such that the total amount of additive/additives is in a range between 0.01 % - 5.0% (w/v),

Vii. preparing the solution of active pharmaceutical ingredient with antifungal effect in the water, acid, base or an organic solvent such that the amount of active pharmaceutical ingredient with the antifungal effect is in a range between 0.01% - 5.0% (w/v),

2. A method according to Claim 1 , characterized by comprising the process steps of; i. preparing chitosan or chitosan salt solution in a range between 0.5% - 4.0% by weight/volume (w/v) inside hydrochloric acid, acetic acid, succinic acid, sulfuric acid, oxalic acid or phosphoric acid or purified water within a range of 0.05 M - 1.0 M,

preparing natural polymer solution/solutions in a range between 0.25% - 5.0% (w/v) within inorganic or organic salt solution/solutions in a range between 0.25 M - 2.0 M,

3. A method according to Claim 1 or Claim 2, characterized in that; chitosan, collagen, starch, gelatin, dextran, actine, agar, alginate, chitin, keratin, cellulose, guar gum, carrageenan, gellan gum, scleroglucan, cyclodextrin, xanthan gum, pectin, inulin, hyaluronic acid, glucomannan and/or hyaluronan and/or at least one derivative thereof or a combination thereof is used as a natural polymer.

4. A method according to Claim 1 or Claim 2, characterized in that; kaolinite, halloysite, vermiculite, saponite, nontronite, disodium hydrogen phosphate (Na2HP04), sodium bicarbonate (NaHCO₃), sodium dihydrogen phosphate (NaH2P04), illite, montmorillonite, chlorite, attapulgite, sepiolite, bentonite, zeolite, fumed silica, starch, modified starch or talc and/or carbonate, b-glycerophosphate, benzoate, acetate, phosphate, malate, lactate, succinate, acrylate and at least one of sodium (Na) and/or potassium (K) and/or calcium (Ca) salts of sulfate or a combination thereof is used as an inorganic or organic additive.

5. A method according to Claim 1 or Claim 2, characterized in that; at least one of fluconazole, itraconazole, griseofulvin, ketoconazole, clotrimazole, oxiconazole, miconazole, and econazole or a combination thereof is used as an active pharmaceutical ingredient with antifungal property.

6. A method according to Claim 1 or Claim 2, characterized in that; the acid is selected from hydrochloric acid, acetic acid, succinic acid, sulfuric acid, oxalic acid or phosphoric acid.

7. A method according to Claim 1 or Claim 2, characterized in that; the base is selected from sodium hydroxide, ammonia, or sodium carbonate.

8. A method according to Claim 1 or Claim 2, characterized in that; acetone, acetonitrile, benzene, diethyl ether, dimethylfomnamide, dimethyl sulfoxide, ethyl alcohol, ethyl acetate, heptane, hexane, chloroform, xylene, petroleum ether, methyl alcohol, carbon tetrachloride or toluene is used as an organic solvent.

9. Temperature-sensitive smart hydrogel with antifungal property that perform controlled drug release prepared through the method according to any one of the preceding claims.

10. A hydrogel according to claim 9, characterized in that, it comprises; chitosan at a rate of at least 15% and at least one natural polymer, one inorganic or organic additive at a rate of at least 3% and active pharmaceutical ingredient with antifungal property at a rate of at least 0.1 %.

11. A hydrogel according to Claim 9, characterized in that, it is in liquid form under room conditions, and in gel form at external skin temperature.

12. A hydrogel according to Claim 11 , characterized in that, skin external temperature is 32 °C.

13. Use of a hydrogel according to one of Claims 9-12 in the treatment of nail fungus.