A bifonazole nanoemulsion solution and a method for preparing the same

Abstract

The application discloses a new bifonazole nanoemulsion solution formula and a preparation process, wherein a main drug is bifonazole, other accessories include (1) isopropyl myristate as an oil-phase solvent, (2) glycerol as a humectant, (3) Tween-80 as a non-ionic surfactant, (4) poloxamer 188 as an emulsifier, (5) sodium benzoate as a preservative and (6) hydrochloric acid or sodium hydroxide as pH adjustment, and a pH value is 5.5-6.5; the preparation process comprises the following steps: (1) preparing an oil phase, (2) preparing an aqueous phase, (3) preparing a primary emulsion, (4) homogenizing to form a nanoemulsion, (5) adjusting the pH to 5.5-6.5 and constant volume, (6) filling and the like. The bifonazole nanoemulsion solution prepared by the application has good stability, no stimulation and no greasy feeling for patients, and greatly improves the drug-taking feeling of the patients.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, and more specifically, to a nanoemulsion solution containing bifonazole and its preparation method. Background Technology

[0002] Bifonazole is a broad-spectrum antifungal drug primarily used to treat fungal infections of the skin. It belongs to the imidazole class of antifungal drugs and exerts its antifungal effect by inhibiting the synthesis of ergosterol in the fungal cell membrane, thereby causing fungal cell structure destruction and death.

[0003] Bifonazole is widely used to treat a variety of fungal skin diseases, such as tinea corporis, tinea cruris, tinea pedis (athlete's foot), and tinea versicolor. The dosage forms of the drug currently available in China are mostly creams, gels, and solutions. It is usually used by applying the cream or solution topically to the affected area.

[0004] Because bifonazole is only slightly soluble in methanol or anhydrous ethanol and almost insoluble in water, commercially available bifonazole solutions typically use large amounts of ethanol as a solvent. However, for skin application, the defatting effect of ethanol can lead to drier skin, exacerbating existing skin problems. Furthermore, the irritant properties of ethanol can cause severe pain on ulcerated or broken skin, and long-term use of high-concentration ethanol products may weaken the skin barrier function. Therefore, developing a solution free of ethanol or other organic solvents could provide patients with a better medication experience and meet clinical needs. Summary of the Invention

[0005] The present invention provides a novel formulation and preparation process for a bifonazole solution, characterized by being ethanol-free, using oil as a solvent to dissolve bifonazole, and employing a specific process to encapsulate the oil phase with the water phase to form an oil-in-water nanoemulsion solution. This solution is non-irritating and non-greasy for patients, greatly improving their medication experience.

[0006] The first objective of this invention is achieved through the following technical solution:

[0007] A bifonazole nanoemulsion solution comprises an active ingredient, bifonazole, excipients, and purified water. The pH value of the bifonazole nanoemulsion solution is 5.5 to 6.5. The excipients include: (1) isopropyl myristate as an oil phase solvent, (2) glycerin as a humectant, (3) Tween-80 as a nonionic surfactant, (4) poloxamer 188 as an emulsifier, (5) sodium benzoate as a preservative, and (6) hydrochloric acid or sodium hydroxide as a pH adjuster.

[0008] In one embodiment of the present invention, the active ingredient is bifonazole, and the types and percentages of other components are as follows:

[0009]

[0010] A second objective of this invention is to provide a method for preparing a bifonazole nanoemulsion solution.

[0011] (1) Preparation of oil phase: Add the prescribed amount of bifonazole to isopropyl myristate, stir and dissolve it to form a pale yellow transparent solution.

[0012] (2) Preparation of aqueous phase: Take a small amount of purified water, add sodium benzoate, glycerol, Tween-80 and poloxamer 188, and stir to dissolve.

[0013] (3) Preparation of colostrum: Heat the oil phase and water phase to 55±5℃ at the same time, and the temperature difference between the two phases shall not exceed 2℃. Keep the oil phase in the container and stir at a speed of 550±50rpm. Slowly add the water phase to the oil phase at a speed of no more than 10ml / min. After all the phases are completed, stop the heat preservation and reduce the stirring speed to 250±125rpm. Continue stirring until the liquid temperature drops to 30~25℃. At this time, a uniform light yellow suspension can be obtained.

[0014] (4) High-shear emulsifier emulsification: The pale yellow suspension prepared in step (3) is emulsified in a high-shear emulsifier. The speed of the high-shear emulsifier is set to >10000 rpm and stirred for 15 min. At the same time, the temperature of the emulsion should not exceed 60℃. The emulsion should be fine and uniform pale yellow in appearance.

[0015] (5) Formation of nanoemulsion: The emulsion prepared in step (4) is cooled to 25℃±5℃, and the emulsion is passed through a high-pressure homogenizer by a peristaltic pump. The pressure of the high-pressure homogenizer is >15000psi, and the temperature of the emulsion is kept not more than 60℃ to obtain a light yellow nanoemulsion with an opalescent appearance. After cycling, the average particle size and transmittance of the emulsion droplets are measured. When the particle size of the emulsion droplets is <50 nm and the transmittance is >70% (610 nm), the cycling can be stopped.

[0016] (6) Adjust pH: Adjust the pH of the nanoemulsion solution prepared in step (5) to 5.5-6.5 with sodium hydroxide or hydrochloric acid, add water to make up the volume, measure its transmittance >80% (610nm), and fill it into a 10ml spray bottle to obtain the solution.

[0017] The beneficial technical effects of this invention are mainly reflected in the following aspects:

[0018] (1) Using nanoemulsion technology, bifonazole is dissolved in the oil phase and made into an oil-in-water emulsion, which solves the dissolution problem of bifonazole and avoids the use of ethanol.

[0019] (2) Animal skin irritation experiments clearly show that water-in-oil nanoemulsion solutions are superior to ordinary ethanol-containing solutions.

[0020] (3) The nanoemulsion solution prepared by the present invention does not contain ethanol, so the content of the product will not increase during storage due to the volatilization of ethanol, and the stability is good. Detailed Implementation

[0021] The beneficial effects of the present invention can be demonstrated through the following series of tests.

[0022] Experimental Example 1:

[0023]

[0024] Preparation process:

[0025] (1) Preparation of oil phase: Take isopropyl myristate, add bifonazole, stir and dissolve it to form a pale yellow transparent solution 1.

[0026] (2) Preparation of aqueous phase: Take about 50% of the prescribed amount of purified water, add sodium benzoate, glycerol, Tween-80 and poloxamer 188, and stir to dissolve.

[0027] (3) Preparation of colostrum: Heat the oil phase and water phase to 55°C at the same time, and the temperature difference between the two phases shall not exceed 2°C. Keep the oil phase stirring at 550 rpm in the container, and slowly add the water phase to the oil phase at a rate of no more than 10 ml / min. After all the oil phase is added, stop the heating and reduce the stirring speed to 250 rpm. Continue stirring until the liquid temperature drops to 30-25°C. At this point, a uniform pale yellow suspension can be obtained.

[0028] (4) High-shear emulsifier emulsification: The pale yellow suspension prepared in step (3) is emulsified in a high-shear emulsifier. The speed of the high-shear emulsifier is set to 12000 rpm and stirred for 15 min. At the same time, the temperature of the emulsion should not exceed 60℃. The emulsion should be fine and uniform pale yellow.

[0029] (5) Formation of nanoemulsion: The emulsion prepared in step (4) is cooled to 25°C, and the emulsion is passed through a high-pressure homogenizer by a peristaltic pump. The pressure of the high-pressure homogenizer is 18000psi, and the temperature of the emulsion is kept not more than 60°C to obtain a light yellow nanoemulsion with an opalescent appearance. After cycling, its transmittance is measured. When the transmittance is >70% (610nm), the cycling can be stopped.

[0030] (6) Adjust pH: Adjust the pH of the nanoemulsion solution prepared in step (5) to 6.0 with sodium hydroxide or hydrochloric acid, add water to make up the volume, measure its transmittance >80% (610nm), and fill it into a 10ml spray bottle to obtain the final product.

[0031] Results analysis:

[0032] The results of the formulation screening show that when the proportions of the oil phase solvent, surfactant, and emulsifier are adjusted, the particle size of the resulting nanoemulsions varies significantly under the same process parameters. The smaller the particle size, the higher the transmittance of the solution. Therefore, the optimal proportions of each formulation component are as follows:

[0033]

[0034]

[0035] Example 1:

[0036] Preparation of prescription

[0037]

[0038] Preparation process:

[0039] Same as Experiment 1.

[0040] Example 2:

[0041] Preparation of prescription

[0042]

[0043]

[0044] Preparation process

[0045] Same as Experiment 1.

[0046] Example 3:

[0047] Preparation of prescription

[0048]

[0049] Preparation process

[0050] Same as Example 1. Comparative Example 1:

[0051] Preparation of prescription

[0052]

[0053]

[0054] Preparation process

[0055] Mix the prescribed amount of isopropyl myristate with 95% ethanol and stir for 10 minutes. Add 3.0 g of bifonazole and continue stirring until completely dissolved. Then fill into containers to obtain the final product.

[0056] Comparative Example 2:

[0057] Preparation of prescription

[0058]

[0059] Preparation process: Add the prescribed amount of bifonazole to the prescribed amount of isopropyl myristate, stir until completely dissolved, and then fill into containers.

[0060] Example 4: Summary of Key Detection Indicators for Each Prescription

[0061]

[0062] Example 5: Guinea Pig Skin Irritation Test

[0063] (1) Animal preparation before the experiment: Hair was removed from both sides of the back of the guinea pig, with a hair removal area of ​​about 5cm×5cm. The skin was then washed with warm water. After 24 hours, the skin at the hair removal site was checked to ensure that there was no injury caused by hair removal before the animal could be used for the experiment. The next day, the hair-removed guinea pig was used to make a "well" pattern with a sterile No. 8 needle to prepare broken skin.

[0064] (2) Experimental grouping: The animals were randomly divided into three groups: intact skin group (applied with bifonazole nanoemulsion solution prepared in Example 1), damaged skin group (applied with bifonazole nanoemulsion solution prepared in Example 1), intact skin group (applied with bifonazole solution prepared in Comparative Example 1), and damaged skin group (applied with bifonazole solution prepared in Comparative Example 1). Each group consisted of 10 animals, half male and half female.

[0065] (3) Administration method: Using the self-comparison method of left and right sides of the same body, a 5cm×5cm gauze, 4 layers, was soaked in 20ml of the bifonazole nanoemulsion solution prepared in Example 1 or the bifonazole solution prepared in Comparative Example 1, and applied to the hairless skin on the left side, covered with plastic film, and then fixed with non-irritating adhesive tape and bandage; the same method was used to apply gauze soaked in 20ml of purified water to the skin on the right side as a blank control. After 10 minutes of application, the test substance was removed and the administration site was cleaned with warm water. Aseptic operation was performed on broken skin. The drug was administered once a day for 7 consecutive days.

[0066] (4) Evaluation method: The stimulation score is determined according to the skin irritation reaction scoring standard in Table 1, and the stimulation intensity of each group is evaluated according to the skin irritation intensity evaluation standard in Table 2.

[0067] Table 1. Scoring criteria for skin irritation reaction

[0068]

[0069] Each guinea pig with erythema and edema has a maximum score of 8 points.

[0070] Table 2. Evaluation Criteria for Skin Irritation Intensity

[0071]

[0072] Average score of stimulation index for each group = (total score of erythema + total score of edema) / number of animals

[0073] (5) Experimental results: Each guinea pig was scored according to Table 1 and Table 2, and the results are shown in Table 3.

[0074] Table 3. Results of Skin Irritation Evaluation

[0075]

[0076]

[0077] Average score of stimulation index for each group = (total score of erythema + total score of edema) / number of animals

[0078] The results above show that the bifonazole nanoemulsion solution is far less irritating to the skin than the regular bifonazole solution.

[0079] Example 4: Comparison of stability and content between bifonazole nanoemulsion solution and bifonazole solution

[0080] The content of bifonazole was determined according to the following method: Accurately measure a solution equivalent to approximately 20 mg of bifonazole into a 200 mL volumetric flask, dilute to the mark with ethanol, and mix well. This is the test solution. Prepare a reference solution of the same concentration using ethanol. Use octadecylsilane-bonded silica gel as the packing material, with 0.2% phosphoric acid solution (adjusted to pH 3.5 with triethylamine) as mobile phase A and acetonitrile as mobile phase B; perform linear gradient elution according to the table below; flow rate: 1.0 mL / min; detection wavelength: 254 nm; injection volume: 20 μL.

[0081]

[0082] The test results are as follows:

[0083] Table 4. Comparison of stability content between nanoemulsion solutions and general solutions.

[0084]

[0085] The results above show that the bifonazole nanoemulsion solution remained stable after 6 months of accelerated storage; however, since the bifonazole solution contains a large amount of ethanol, the ethanol will inevitably evaporate during accelerated storage, which will lead to an increase in the content of bifonazole in the solution.

[0086] Example 5: Comparison of bifonazole nanoemulsion solution and bifonazole solution content in different layers of mouse skin

[0087] Twelve SPF-grade ICR mice (male, 18-20g each) were divided into three groups of four mice each. Hair was removed from the back of each mouse. The skin area covered by the drug was 2cm × 2cm. Bifonazole preparations prepared in Example 1, Comparative Example 1, and Comparative Example 2 were applied to each mouse, with a dosage of 0.5ml. After 12 hours of sealing and bandaging, the concentration in each layer of the skin was measured.

[0088] Skin sample collection: Mice were euthanized by cervical dislocation, and the skin to be tested was removed. Subcutaneous tissue and fat were removed, and the skin was rinsed with physiological saline and the surface moisture was absorbed with filter paper. A piece of skin approximately 1cm × 2cm in size was cut off, and the stratum corneum was peeled off 30 times with Scotch tape. The stratum corneum was considered completely peeled off when the tape was clean.

[0089] The concentrations of bifonazole in the stratum corneum and the active skin layer after the stratum corneum was peeled off were measured, and the results are shown in Table 5.

[0090] Table 5. Bifonazole content in the stratum corneum and active skin layer of various formulations.

[0091]

[0092] Bifonazole solution is mainly used for superficial fungal infections of the skin. Superficial fungal infections generally affect the outermost layer of the skin, the stratum corneum; therefore, the ability of the drug to penetrate the stratum corneum effectively has a crucial impact on its efficacy.

[0093] Typical bifonazole solutions contain ethanol. Ethanol, as a penetration enhancer for skin administration, can alter the arrangement of stratum corneum cells, reducing their density and thus providing more channels for drug molecules.

[0094] Bifonazole nanoemulsion solutions do not contain ethanol, which theoretically reduces its skin penetration. However, due to the use of nanoemulsion technology, the nanoemulsions possess an appropriate hydrophilic-lipophilic balance (HLB), which facilitates the distribution of the drug between the aqueous and oil phases. This balance allows the drug to more easily cross the skin's lipid barrier, and smaller-particle-size nanoemulsions exhibit significantly better penetration than larger-particle-size nanoemulsions. When the particle size is around 20 nm, it is superior to bifonazole solutions containing ethanol.

[0095] Therefore, the proportions of each component in the bifonazole nanoemulsion solution formulation are further optimized as follows:

[0096]

Claims

1. A bifonazole nanoemulsion solution, characterized in that, Its ingredients are composed of the active ingredient bifonazole, excipients, and purified water.

2. The bifonazole nanoemulsion solution as described in claim 1, characterized in that, The pH value of the bifonazole nanoemulsion solution is 5.5 to 6.5, and the excipients include: (1) isopropyl myristate as an oil phase solvent, (2) glycerin as a humectant, (3) Tween-80 as a nonionic surfactant, (4) poloxamer 188 as an emulsifier, (5) sodium benzoate as a preservative, and (6) one of hydrochloric acid or sodium hydroxide as a pH adjuster.

3. The bifonazole nanoemulsion solution as described in claim 2, characterized in that, The types and percentages of its components are as follows:

4. The bifonazole nanoemulsion solution as described in claim 2, characterized in that, The types and percentages of its components are further optimized as follows:

5. The bifonazole nanoemulsion solution as described in claim 2, characterized in that: The preparation method is as follows: (1) Preparation of oil phase: Add the prescribed amount of bifonazole to isopropyl myristate, stir and dissolve it to form a pale yellow transparent solution; (2) Preparation of aqueous phase: Take a small amount of purified water, add sodium benzoate, glycerol, Tween-80 and poloxamer 188, and stir to dissolve; (3) Preparation of colostrum: Heat the oil phase and water phase to 55±5℃ at the same time, and the temperature difference between the two phases shall not exceed 2℃. Keep the oil phase in the container and stir at a speed of 550±50rpm. Slowly add the water phase to the oil phase at a speed of no more than 10ml / min. After all the oil phase is added, stop the heat preservation and reduce the stirring speed to 250±125rpm. Continue stirring until the liquid temperature drops to 30~25℃. At this time, a uniform pale yellow suspension can be obtained. (4) High-shear emulsifier emulsification: The pale yellow suspension prepared in step (3) is emulsified in a high-shear emulsifier. The speed of the high-shear emulsifier is set to >10000 rpm and stirred for 15 min. At the same time, the temperature of the emulsion should not exceed 60℃. The emulsion should be fine and uniform pale yellow in appearance. (5) Formation of nanoemulsion: The emulsion prepared in step (4) is cooled to 25℃±5℃, and the emulsion is passed through a high-pressure homogenizer by a peristaltic pump. The pressure of the high-pressure homogenizer is >15000psi, and the temperature of the emulsion is kept not more than 60℃ to obtain a light yellow nanoemulsion with an opalescent appearance. After cycling, the average particle size and transmittance of the emulsion droplets are measured. When the particle size of the emulsion droplets is <50 nm and the transmittance is >70% (610 nm), the cycling can be stopped. (6) Adjust pH: Adjust the pH of the nanoemulsion solution prepared in step (5) to 5.5-6.5 with sodium hydroxide or hydrochloric acid, add water to make up the volume, measure its transmittance >80% (610nm), and fill it into a 10ml spray bottle to obtain the solution.

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