Voriconazole topical preparation and its preparation method

Abstract

The present invention relates to antifungal drug preparations, and particularly to voriconazole topical preparations and their preparation methods. The voriconazole topical preparation at least comprises voriconazole, a matrix material and a solubilizer, wherein the solubilizer is an isopropyl ester or a hydrocarbon solvent. The voriconazole topical preparation of the present invention can more effectively target the affected area, and solves the problem of poor stability of voriconazole during the preparation of the voriconazole topical preparation. Especially in the presence of water, voriconazole is prone to hydrolysis and the products are recombined through the retro-aldol reaction to generate inactive isomeric impurities.

Description

Technical Field

[0001] The present invention relates to antifungal pharmaceutical preparations, and particularly to voriconazole topical preparations and their preparation methods. Background Art

[0002] The chemical name of voriconazole is: (2R,3S)-2-(2,4-difluorophenyl)-3-(5-fluoro-4-pyrimidinyl)-1-(1H-1,2,4-triazol-1-yl)-2-butanol, and its molecular formula is: C 16 H 14 F3N5O with a molecular weight of: 349.3.

[0003]

[0004] Voriconazole is a second-generation triazole antifungal drug, which overcomes the problems of the first-generation antifungal drugs such as fluconazole and itraconazole, including narrow antibacterial spectrum, low bioavailability and drug resistance. It is used to treat invasive aspergillosis in adults and children over 2 years old, candidemia, esophageal candidiasis in non-neutropenic patients and other deep tissue Candida infections, as well as severe fungal infections caused by Scedosporium apiospermum and Fusarium species (including Fusarium solani).

[0005] Clinically, cutaneous fungal infections can be divided into superficial mycosis (the infection site is limited to the stratum corneum, hair and nails), subcutaneous mycosis (infection of the dermis and subcutaneous tissue) and systemic mycosis (also known as invasive mycosis) according to the infection site. Superficial mycosis is mainly treated with topical preparations, and common drugs include: topical preparations such as ketoconazole, ciclopirox and terbinafine, among which imidazole drugs represented by ketoconazole account for the largest proportion. Due to the relatively high hepatotoxicity of ketoconazole, its oral dosage forms have been successively discontinued in Europe, Australia and China. In 2017, ketoconazole-related over-the-counter drugs such as lotions and ointments were removed from the over-the-counter drug list in China and subject to prescription monitoring management.

[0006] The marketed formulations of voriconazole include freeze-dried powder injections for intravenous administration, tablets and dry suspensions for oral administration, with the trade name: Vefend. Voriconazole is a derivative of fluconazole, with a broader antibacterial spectrum, having a bactericidal effect on Aspergillus; having antibacterial activity against Candida, Scedosporium and Fusarium; and also having good antibacterial activity against Cryptococcus, dimorphic fungi, etc. The research by Carrillo-Munoz et.al. shows that voriconazole has better in vitro antibacterial activity against fungi causing onychomycosis such as Candida, Candida albicans, and Candida pseudotropicalis than terbinafine and itraconazole. Bueno J G et.al. determined the antibacterial activity of voriconazole against dermatophytes causing onychomycosis (such as Trichomonas rubra, Trichomonas interdigitale, etc.), and the geometric mean of its MIC is 0.037 - 0.107 g / mL, with good antibacterial activity. Their research also shows that voriconazole has relatively high antifungal activity against other related dermatophytes. Muangkaew W et.al. conducted in vitro antibacterial tests on fungi of common clinical skin diseases (including: Trichophyton, Trichophyton rubrum, Sporothrix, etc.) using different antifungal drugs. The results show that voriconazole has a better antibacterial effect on Candida than fluconazole, itraconazole, and terbinafine.

[0007] Voriconazole oral and injection formulations have been clinically used for a long time, and their safety is superior to that of imidazole antifungal drugs represented by ketoconazole. In vitro antibacterial activity tests show that it has good antibacterial activity against fungi causing skin infections, and it may be a safe and effective means for treating refractory infections (such as onychomycosis) or skin fungal infections in immunocompromised patients. For superficial fungal infections, oral or injection voriconazole is not easily directly targeted at the affected area. If voriconazole is prepared into a topical preparation, it can be directly targeted at the affected area and can be treated more effectively.

[0008] However, voriconazole has poor stability, especially in an aqueous solution state. Voriconazole is prone to hydrolysis, and through the recombination of the retro-aldol reaction products, inactive isomeric impurities are generated. Therefore, it is very difficult to prepare voriconazole into long-term stable aqueous ointments, injections, and eye drops. In addition, voriconazole has a logD of 1.8 and is a semi-polar compound, with poor solubility. Its solubility in an aqueous solution is only 0.65 mg / ml, and it cannot be solubilized by conventional solubilization methods such as oils, surfactants, or water-miscible co-solvents. Summary of the Invention

[0009] The object of the present invention is to provide a voriconazole topical preparation that can be directly targeted at the affected area for treating superficial fungal infections, and solves the problems of poor solubility and instability in water of voriconazole, and provides a voriconazole topical preparation with good stability, good solubility, and high intradermal distribution.

[0010] Another object of the present invention is to provide a preparation method of the voriconazole topical preparation.

[0011] To solve the problems existing in the background art, the present invention adopts the following technical solutions:

[0012] Voriconazole topical preparation, comprising at least voriconazole, a matrix material and a solubilizer, wherein the solubilizer is an isopropyl ester or a hydrocarbon solvent.

[0013] Preferably, the voriconazole topical preparation of the present invention consists of voriconazole, a matrix material and a solubilizer, wherein the solubilizer is an isopropyl ester or a hydrocarbon solvent.

[0014] Preferably, the isopropyl ester is diisopropyl adipate.

[0015] Preferably, the hydrocarbon solvent is hexadecane.

[0016] Preferably, the matrix material is one or a mixture of myristyl alcohol, cetyl alcohol, stearyl alcohol, emulsifying wax, microcrystalline wax, paraffin wax or liquid paraffin, petrolatum, mineral oil, beeswax, lanolin, lanolin alcohol.

[0017] The voriconazole topical preparation of the present invention comprises 0.3% - 3% of voriconazole, 67% - 94% of a matrix material and 5% - 30% of a solubilizer by weight percentage.

[0018] More preferably, the voriconazole topical preparation provided by the present invention comprises 0.3% - 3% of voriconazole, 67% - 94% of a matrix material and 10% - 20% of a solubilizer by weight percentage.

[0019] In a specific embodiment, the voriconazole topical preparation provided by the present invention comprises 1% of voriconazole, 79% of a matrix material and 20% of a solubilizer by weight percentage.

[0020] The present invention also discloses a preparation method of the voriconazole topical preparation, comprising the following steps:

[0021] (1) Adding voriconazole raw material to the solubilizer and stirring to dissolve;

[0022] (2) Melting the matrix material for standby;

[0023] (3) Mixing and stirring to obtain the product.

[0024] The voriconazole topical preparation of the present invention provides a topical antifungal dosage form of voriconazole, which can more effectively target the affected area and solve the problem of poor stability of voriconazole in the preparation process of voriconazole topical preparation. Especially in the presence of water, voriconazole is prone to hydrolysis and recombination of the retro-aldol reaction products to generate inactive isomeric impurities. In the research of the present invention, it is found that voriconazole has good solubility and stability in ester and alkane excipients. Especially after adding isopropyl esters and hydrocarbon solvents, the effect is obvious. Description of the Drawings

[0025] Figure 1 It is the drug release curve of voriconazole ointment in pH 7.2 phosphate buffer solution in the in vitro release determination experiment of Example 7.

[0026] Figure 2 It is a schematic diagram of the administration site in the intradermal permeability experiment of minipigs.

[0027] Figure 3 It is the liquid chromatography corresponding to water as the medium in the compatibility experiment of Example 3.

[0028] Figure 4 It is the liquid chromatography corresponding to propylene glycol as the medium in the compatibility experiment of Example 3.

[0029] Figure 5 It is the liquid chromatography corresponding to oleic acid as the medium in the compatibility experiment of Example 3.

[0030] Figure 6 It is the liquid chromatography corresponding to diisopropyl adipate as the medium in the compatibility experiment of Example 3. Detailed Embodiments

[0031] The present invention will be further described below with reference to the embodiments.

[0032] Example 1: Preparation of voriconazole ointment

[0033] Prescription:

[0034]

[0035]

[0036] Preparation process:

[0037] (1) Weigh the prescribed amount of solubilizer in a beaker, heat it in a water bath at 60°C, add the prescribed amount of voriconazole and stir to dissolve as much as possible, and keep it warm for later use;

[0038] (2) Heat the matrix in a water bath at 60°C until it melts completely, and keep it warm for later use;

[0039] (3) Mixing: Slowly pour the drug solution obtained in step (1) into the melted matrix under stirring, and stir evenly. Cool at room temperature to obtain the product.

[0040] Example 2: Solubility experiment of voriconazole in different solvents;

[0041] Solubility of voriconazole in different solvents:

[0042]

[0043] As can be seen from the above table, voriconazole has the highest solubility in diisopropyl adipate.

[0044] Experimental Example 3: Compatibility

[0045] Dissolve voriconazole in the following solvents to prepare an approximately saturated drug-containing solution. The drug-containing solution is placed under accelerated conditions (40 °C / 75% RH), taken out after 7 days, and the related substances are detected with reference to the following liquid chromatography conditions.

[0046]

[0047]

[0048]

[0049] Conclusion: After 7 days of acceleration, voriconazole shows good compatibility and stability in diisopropyl oxalate and hexadecane, and is not easily degraded. Voriconazole shows significant degradation in water, propylene glycol and oleic acid. For impurity calculation, the self-control with a concentration of 1 / 1000 is used. When calculating impurities, the impurity peak area As / the control peak area Ar * correction factor is used. For impurity A and impurity C, the correction factor is 0.7.

[0050] The liquid chromatography corresponding to water as the medium is shown in Figure 3 , and the data corresponding to this chromatogram are as follows:

[0051] RT Area %Area Height USP Plate Count Resolution s / n 1 1.856 676128 10.260 204397 7797 6364.2 2 2.163 400234 6.074 116139 9475 3.60 3616.2 3 4.954 1909 0.029 280 14025 20.91 8.7 4 7.379 5511575 83.637 417744 7563 9.41 13007.1

[0052] The liquid chromatography corresponding to propylene glycol as the medium is shown in Figure 4 , and the data corresponding to this chromatogram are as follows:

[0053] RT Area %Area Height USP Plate Count Resolution s / n 1 1.839 73922 0.564 12975 2509 653.0 2 2.139 45586 0.348 7386 2952 2.01 371.8 3 7.249 12988603 99.088 602708 2862 14.86 30335.3

[0054] The liquid chromatography corresponding to oleic acid as the medium is shown in Figure 5 , and the data corresponding to this chromatogram are as follows:

[0055] RT Area %Area Height USP Plate Count Resolution s / n 1 1.835 102716 1.043 18279 2564 1036.1 2 2.135 63342 0.643 10334 2982 2.04 585.7 3 7.268 9683313 98.314 452799 2931 15.10 25664.6

[0056] The liquid chromatography corresponding to isopropyl adipate as the medium is shown in Figure 6 , and the data corresponding to this chromatogram are as follows:

[0057] RT Area %Area Height USP Plate Count Resolution s / n 1 1.835 1622 0.019 296 2614 19.5 2 2.135 1372 0.016 238 3440 2.09 15.6 3 7.234 8727418 99.966 416956 3036 15.41 27468.7

[0058] Example 4: Stability experiment:

[0059] The voriconazole ointments obtained from Formulation 1, Formulation 2, and Formulation 3 in Example 1 were placed under accelerated conditions for 7 days, and then the appearance and related substances were detected.

[0060]

[0061] Conclusion: After 7 days of acceleration, the total impurities of the voriconazole ointment obtained in Example 1 did not increase significantly, indicating good compatibility.

[0062] Example 5: In vitro skin permeability test was used to evaluate the in vitro percutaneous permeability of different formulations.

[0063] Experimental procedure:

[0064] (1) Take out the frozen pig skin and thaw it in 0.9% physiological saline at room temperature; after thawing, use an electric clipper to shave the pig hair on the surface of the pig skin, and use scissors to remove the subcutaneous fat tissue, and set aside;

[0065] (2) Place the experimental skin in the receiving chamber of the Franz vertical diffusion cell, and use surgical scissors to trim the edges, with a margin of not less than 5 mm; after trimming, clamp it with a clamp. And accurately weigh the weight of the whole set of diffusion cells.

[0066] (3) Use a 1 ml syringe, cut off the front part of the syringe with a utility knife to make the front end open for sucking and extruding the sample, and reduce the influence of extrusion stress on the performance of the sample to be tested; use this device to absorb about 0.2 - 0.3 ml of the sample and evenly coat it on the skin surface (the sample addition amount is about 300 mg); weigh the diffusion cell after adding the sample, and subtract the weight before adding the sample to obtain the sample weight; after adding the sample, seal it with a sealing film to prevent the sample from drying out during the experiment.

[0067] (4) Use phosphate buffer solution with pH 7.2 as the receiving medium, and the test temperature is 32°C ± 1°C;

[0068] (5) After 6 hours, extract the stratum corneum and epidermis respectively. Use the extraction medium to extract and determine the drug concentration therein.

[0069]

[0070] Example 6: Preparation of voriconazole ointments with different formulations

[0071] Using petrolatum as the matrix and diisopropyl adipate as the solubilizer and penetration enhancer, Prescriptions 1, 4 - 6 were prepared respectively.

[0072]

[0073] Experimental procedures:

[0074] (1) Weigh approximately the prescribed amount of diisopropyl adipate in a beaker, heat it in a water bath at 60°C, add the prescribed amount of voriconazole and stir to dissolve it as completely as possible, and keep it warm for later use.

[0075] (2) Heat the petrolatum matrix in a water bath at 60°C until it melts completely, and keep it warm for later use.

[0076] (3) Mixing: Slowly pour the diisopropyl adipate drug solution into the melted petrolatum under stirring, and stir evenly. Cool it at room temperature to obtain the product.

[0077] Example 7: Determination of in vitro release

[0078] Using a Franz diffusion cell, with phosphate buffer solution at pH 7.2 as the extraction medium, the test temperature was 32°C ± 0.5°C, and the diffusion membrane used was a 0.45 - μm polysulfone membrane ( Pall, USA), to conduct the in vitro permeability test. The test procedures are as follows:

[0079] (1) Add the extraction medium to a conical flask of about 250 mL and preheat it in a water bath at 32°C. During this period, use a thermometer to determine the temperature of the medium. After the medium temperature reaches 32°C ± 0.5°C, keep it for later use.

[0080] (2) Add the magnetic rotor to the diffusion chamber, and then clamp the test polysulfone membrane between the diffusion chamber and the sample chamber.

[0081] (3) After confirming that the medium temperature reaches 32°C ± 0.5°C, start adding the sample. Weigh and zero the diffusion cell clamped with the polysulfone membrane on the balance; slowly squeeze no less than 300 mg of the sample onto the polysulfone membrane, level it with the end of the syringe, and evenly spread it over the entire surface.

[0082] (4) Draw out the preheated medium and carefully add it to the diffusion chamber of the diffusion cell. Avoid mixing air bubbles when adding the liquid.

[0083] (5) Set the rotation speed to 600 rpm and start stirring. Ensure that the magnetic stirring in the diffusion cell rotates normally without jumping or shaking.

[0084] (6) Sampling was carried out at 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, and 24 hours respectively. Using a sampling needle, samples were taken from the middle position of the receiving chamber of the Franz diffusion cell. Each time 1 ml of sample was taken, and at the same time 1 ml of medium was replenished to keep the liquid level of the receiving medium always in contact with the skin surface. Calculate the drug content in the extraction medium at different time points for calculating the drug release amount M per unit area; The square root of M and time t conforms to the following formula:

[0085]

[0086] Wherein,

[0087] M is the drug release amount per unit area (μg / cm 2 );

[0088] t is the sampling time;

[0089] k represents the drug release rate.

[0090] The experimental results are as follows:

[0091] The drug release rate is related to diisopropyl adipate in the formulation. As the dosage of diisopropyl adipate increases, the drug release rate of voriconazole accelerates.

[0092]

[0093] Example 8: In-vivo animal test of minipig dermal permeability

[0094] Minipigs aged 3 - 5 months and weighing 15 - 20 kg were selected and acclimated for at least one week before the first administration. Before animal administration, the back was depilated. Four areas were selected on each side of the center line of the back, for a total of 8 areas, each with an area of 8 cm × 4 cm. The areas on the left and right sides were spaced 5 cm apart, and the areas on the same side were spaced 4 cm apart. Administration was carried out at 4 hours, 8 hours, 12 hours, and 24 hours before sacrifice, and bandaging was performed after administration. Each administration site was washed with warm water before sample collection. See specific details in Figure 2 .

[0095] At the last time point, 4 hours after topical administration, the administration site was washed with warm water and then sampled. After the skin of the administration site was removed as a whole, subcutaneous fat was separated and removed. Adjust the thickness of the skin grafting knife to 0.1 mm and take once at the administration site for the epidermal layer; Adjust the thickness of the skin grafting knife to 0.75 mm and take twice successively downward at the same site. The two tissues taken were used as the dermal layer. Approximately 4 cm of each separated tissue was taken 2 for the detection of voriconazole and voriconazole N-oxide.

[0096]

[0097]

[0098] Voriconazole N-oxide is the main metabolite of voriconazole in vivo. Literature data show that (P Morlière, A M S Silva, R S G R Seixas, F Boscá, J-C Mazière, J Ferreira, R Santus, P Filipe. Photosensitisation by voriconazole-N-oxide results from a sequence of solvent and pH-dependent photochemical and thermal reactions. J Photochem Photobiol B. 2018, 187:1-9): the in vitro molar extinction coefficient (MEC) of voriconazole N-oxide > 1000 may be related to the phototoxicity of voriconazole. Excessive voriconazole N-oxide in the dermis may produce a phototoxic reaction after being irradiated by light.

[0099]

[0100] The distribution of voriconazole in the epidermis is related to the release rate of the ointment. The faster the release, the more the amount of drug released, and the higher the content of voriconazole in the epidermis; the drug distributions of Prescription 6 and Prescription 1 in the dermis are similar, greater than that of Prescription 5 but less than that of Prescription 1; the distributions of voriconazole N-oxide of Prescription 5, Prescription 6 and Prescription 1 in the dermis are similar, much lower than that of Prescription 4.

[0101] The results show that: Prescription 5 has the slowest drug release, and its drug distribution in the epidermis and dermis is the least; Prescription 4 has the fastest drug release, its voriconazole distribution in the epidermis is higher, and its distributions of voriconazole and voriconazole N-oxide in the dermis are much higher than those of other prescriptions. Considering the potential phototoxicity of voriconazole N-oxide, the phototoxicity of Prescription 4 may be greater than that of Prescription 1, 5 and 6; Prescription 1 has a higher drug distribution in the epidermis, and the voriconazole and voriconazole N-oxide in the dermis are similar to those of Prescription 5 and Prescription 6, and may have the best curative effect and the least side effects.

Claims

1. Voriconazole topical preparation, characterized in that It comprises voriconazole 1%, matrix material 79%, and solubilizer 20% by weight percentage, wherein the solubilizer is diisopropyl adipate.

2. The voriconazole topical preparation according to claim 1, wherein The voriconazole topical preparation is characterized in that the matrix material is one or a mixture of myristyl alcohol, cetyl alcohol, stearyl alcohol, emulsifying wax, microcrystalline wax, petrolatum, mineral oil, beeswax, lanolin, and wool alcohol.

3. The preparation method of the voriconazole topical preparation according to claim 1, characterized in that It comprises the following steps: (1) Add the voriconazole raw material to the solubilizer and stir to dissolve. (2) Melt the matrix material for standby. (3) Obtain it by mixing and stirring.

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