Preparation method of compound menthol ointment

Abstract

The present invention discloses a method for preparing a compound menthol ointment, comprising the following steps: preparing menthol and / or camphor microcrystals; coating the microcrystals with a wall material to obtain microcapsules; and then mixing the microcapsules with a matrix and other oil-soluble active ingredients to prepare the compound menthol ointment. Camphor and / or menthol crystals with an average particle size of 1 to 10 μm are obtained using a solvent displacement recrystallization method. These crystals serve as the core material for preparing microcapsules. After the microcapsules rupture, oil-soluble components of the matrix or skin oils slowly dissolve the crystals, allowing the camphor and / or menthol components to slowly come into contact with air, which helps slow their volatilization and thus prolongs the cooling effect on the skin.

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical preparations, in particular to a method for preparing a compound menthol ointment. Background Art

[0002] Compound menthol ointment is an over-the-counter medication used to treat nasal congestion caused by colds, insect bites, chapped skin, minor burns, abrasions, sunburn, and itchy skin. It typically contains ingredients such as menthol, camphor, and eucalyptus oil to provide a cooling sensation. However, these ingredients are highly volatile, so topical ointments or solutions containing these substances only provide a short-lived cooling sensation and are unlikely to provide long-lasting relief from itching or a refreshing effect.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The invention provides a preparation method of a compound menthol ointment, aiming to prolong the skin feeling effect of cooling ingredients including camphor and menthol on the skin.

[0005] The present invention is achieved in that:

[0006] In a first aspect, the present invention provides a method for preparing a compound menthol ointment, comprising the following steps:

[0007] (1) preparing microcrystals: dissolving a cooling ingredient in ethanol to obtain an organic phase; adding the organic phase to pure water, allowing the mixture to stand for crystallization, and obtaining microcrystals after solid-liquid separation; the cooling ingredient comprises at least one of menthol and camphor;

[0008] (2) Preparation of microcapsules: Dispersing microcrystals in an aqueous solution of the wall material, homogenizing, and spray drying to obtain microcapsules;

[0009] (3) preparing the matrix: heating and melting the matrix to obtain a matrix liquid;

[0010] (4) Preparation of compound menthol ointment: Add the oil-soluble active ingredient into the matrix liquid, keep warm and stir evenly, add the microcapsule after cooling and stir evenly, can while hot, and obtain the compound menthol ointment after cooling.

[0011] In some embodiments of the present invention, the particle size of the microcrystals is 0.5 to 20 μm; preferably, the average particle size of the microcrystals is 1 to 10 μm.

[0012] In some embodiments of the present invention, the wall material includes a temperature sensitizer.

[0013] In some embodiments of the present invention, the thermosensitizer is polyethylene glycol 1000 vitamin E succinate.

[0014] In some embodiments of the present invention, the wall material further comprises sodium starch octenylsuccinate and maltodextrin; preferably, the viscosity of sodium starch octenylsuccinate at 25° C. is 20 to 100 mPa·s.

[0015] In some embodiments of the present invention, the mass percentage of the wall material in the aqueous solution of the wall material is 10% to 30%.

[0016] In some embodiments of the present invention, the mass ratio of the microcrystals to the wall material is 0.8 to 2:1.

[0017] In some embodiments of the present invention, the concentration of the cooling component in the organic phase is 0.2 to 0.3 g / mL.

[0018] In some embodiments of the present invention, the volume ratio of the organic phase to pure water is 1:8-12.

[0019] In some embodiments of the present invention, the solid-liquid separation method is centrifugation or filter press.

[0020] In some embodiments of the present invention, the spray drying temperature is 30-55°C.

[0021] In some embodiments of the present invention, the base comprises at least one of paraffin wax, ozokerite, petrolatum, zinc wax, and lanolin.

[0022] In some embodiments of the present invention, the oil-soluble active ingredient includes at least one of methyl salicylate, eucalyptus oil, turpentine oil, clove oil, rose essential oil, cinnamon oil, olive oil, thymol, and silicone oil.

[0023] In a first aspect, the present invention provides a compound menthol ointment prepared by the preparation method of any embodiment.

[0024] A compound menthol ointment is composed of the following raw materials by weight based on a total weight of 1000g: 50-100g of menthol, 90-150g of camphor, 70-250g of wall material, 250-300g of oil-soluble active ingredient, and the rest as a matrix.

[0025] The present invention has the following beneficial effects:

[0026] The present invention provides a method for preparing a compound menthol ointment, adopts solvent replacement recrystallization method to obtain small-sized camphor and / or menthol crystals, uses it as core material to prepare microcapsules, after microcapsule rupture, the oil-soluble components of the external matrix or skin grease slowly dissolve the crystals, so that camphor and / or menthol components slowly contact air, which is conducive to slowing down its volatilization, thereby prolonging the cooling skin feeling effect. Further, the present invention adds a thermosensitive agent to the wall material of the microcapsule, and the addition of the thermosensitive agent is conducive to promoting the microcapsule to release camphor and / or menthol components at skin temperature, thereby preparing a compound menthol ointment with different sustained-release effects by controlling the amount of the thermosensitive agent. In addition, the present invention prepares sustained-release microcapsules with camphor and / or menthol, which is conducive to improving the accuracy of the two feeding ratios during the preparation process, and is conducive to improving the stability of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The optical microscope image of the menthol microcrystals (a) prepared in Example 1 and the physical image of the raw material menthol (b) are shown.

[0028] Figure 2 The release rates of menthol microcrystals and raw menthol at different times.

[0029] Figure 3 The release rates of menthol microcrystals and raw menthol at different temperatures. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0031] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0032] Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0033] In the embodiment of the present application, the term "or / and" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A or / and B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0034] In addition, the character “ / ” in this article generally indicates that the previous and next related objects are in an “or” relationship.

[0035] In the embodiments of the present application, "multiple" means more than two (including two). Similarly, "multiple groups" means more than two groups (including two groups), and "multi-layer" means more than two layers (including two layers), unless otherwise clearly specified and limited.

[0036] In the embodiments of the present application, “at least one” means one or more than one.

[0037] In the embodiments of the present application, the directions or positional relationships indicated by the technical terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", etc. are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific direction or be constructed in a specific direction, etc., and should not be understood as limiting the embodiments of the present application. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific circumstances.

[0038] Sources of some raw materials:

[0039] Sodium starch octenylsuccinate, viscosity (25°C) 72 mPa·s, was purchased from Deqing Sanfu Food Co., Ltd.

[0040] Maltodextrin, DE value 18-20, was purchased from Shandong Xiwang Sugar Co., Ltd.

[0041] Polyethylene glycol 1000 vitamin E succinate, melting point 34-38 °C, was purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd.

[0042] The following is a specific embodiment to further illustrate the solution of the present invention.

[0043] Example 1

[0044] A method for preparing a compound menthol ointment comprises the following steps:

[0045] (1) Menthol was dissolved in anhydrous ethanol to obtain a menthol organic phase with a concentration of 0.25 g / mL. The menthol organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 h. The mixture was then filtered to obtain menthol microcrystals with an average particle size of 2.4 μm. The volume ratio of the menthol organic phase to pure water was 1:10.

[0046] Camphor was dissolved in anhydrous ethanol to obtain a camphor organic phase with a concentration of 0.3 g / mL. The camphor organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 hours. Camphor microcrystals were obtained by filter pressing, with an average particle size of 1.4 μm. The volume ratio of the camphor organic phase to pure water was 1:10.

[0047] (2) Mixing menthol microcrystals and camphor microcrystals in an aqueous solution of a wall material according to a formula, homogenizing to obtain a suspension, and drying the suspension in a spray freeze dryer to obtain microcapsules.

[0048] The wall material is composed of sodium starch octenylsuccinate, maltodextrin, and polyethylene glycol 1000 vitamin E succinate in a mass ratio of 60:10:10; the mass percentage of the wall material in the aqueous solution of the wall material is 15%; the mass ratio of microcrystals to wall material is 1.4:1; and the spray drying temperature is 40°C.

[0049] (3) Heat the matrix to 100°C and stir to melt to obtain a matrix liquid, which is then kept warm for later use.

[0050] The matrix is ​​composed of solid paraffin, ozokerite and white vaseline in a mass ratio of 85:1:180.

[0051] (4) Add the oil-soluble active ingredient to the matrix liquid of step (3), keep warm and stir evenly, cool to 40-50°C, add microcapsules and stir at 500 rpm for 30 seconds, can while hot, and then place at 5°C for rapid cooling to obtain the compound menthol ointment.

[0052] The oil-soluble active ingredient is composed of methyl salicylate, eucalyptus oil and turpentine in a mass ratio of 90:50:2.

[0053] A compound menthol ointment, calculated based on a total weight of 1000g, is composed of the following raw materials by weight:

[0054] Menthol 80g, camphor 120g, wall material 143g, oil-soluble active ingredient 270g, matrix: the rest.

[0055] Example 2

[0056] A method for preparing a compound menthol ointment comprises the following steps:

[0057] (1) Menthol was dissolved in anhydrous ethanol to obtain a menthol organic phase with a concentration of 0.2 g / mL. The menthol organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 h. The mixture was then filtered to obtain menthol microcrystals with an average particle size of 1.5 μm. The volume ratio of the menthol organic phase to pure water was 1:12.

[0058] Camphor was dissolved in anhydrous ethanol to obtain a camphor organic phase with a concentration of 0.2 g / mL. The camphor organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 hours. Camphor microcrystals were obtained by filter pressing, with an average particle size of 1.6 μm. The volume ratio of the camphor organic phase to pure water was 1:8.

[0059] (2) Mixing menthol microcrystals and camphor microcrystals in an aqueous solution of a wall material according to a formula, homogenizing to obtain a suspension, and drying the suspension in a spray freeze dryer to obtain microcapsules.

[0060] The wall material is composed of sodium starch octenylsuccinate and maltodextrin in a mass ratio of 60:10; the mass percentage of the wall material in the aqueous solution of the wall material is 30%; the mass ratio of microcrystals to wall material is 0.8:1; and the spray drying temperature is 55°C.

[0061] (3) Heat the matrix to 100°C and stir to melt to obtain a matrix liquid, which is then kept warm for later use.

[0062] The matrix is ​​composed of solid paraffin, ozokerite and yellow vaseline in a mass ratio of 12:1:20.

[0063] (4) Add the oil-soluble active ingredient to the matrix liquid of step (3), keep warm and stir evenly, cool to 40-50°C, add microcapsules and stir at 500 rpm for 30 seconds, can while hot, and then place at 5°C for rapid cooling to obtain the compound menthol ointment.

[0064] Among them, the oil-soluble active ingredient is composed of methyl salicylate, eucalyptus oil, turpentine oil and silicone oil in a mass ratio of 90:50:2:5.

[0065] A compound menthol ointment, calculated based on a total weight of 1000g, is composed of the following raw materials by weight:

[0066] Menthol 50g, camphor 100g, wall material 187g, oil-soluble active ingredient 300g, matrix: the rest.

[0067] Example 3

[0068] A method for preparing a compound menthol ointment comprises the following steps:

[0069] (1) Menthol was dissolved in anhydrous ethanol to obtain a menthol organic phase with a concentration of 0.3 g / mL. The menthol organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 h. The mixture was then filtered to obtain menthol microcrystals with an average particle size of 3.7 μm. The volume ratio of the menthol organic phase to pure water was 1:8.

[0070] Camphor was dissolved in anhydrous ethanol to obtain a camphor organic phase with a concentration of 0.3 g / mL. The camphor organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 hours. Camphor microcrystals were obtained by filter pressing, with an average particle size of 1.1 μm. The volume ratio of the camphor organic phase to pure water was 1:12.

[0071] (2) Mixing menthol microcrystals and camphor microcrystals in an aqueous solution of a wall material according to a formula, homogenizing to obtain a suspension, and drying the suspension in a spray freeze dryer to obtain microcapsules.

[0072] The wall material is composed of sodium starch octenylsuccinate, maltodextrin, and polyethylene glycol 1000 vitamin E succinate in a mass ratio of 60:10:20; the mass percentage of the wall material in the aqueous solution of the wall material is 10%; the mass ratio of microcrystals to wall material is 2:1; and the spray drying temperature is 30°C.

[0073] (3) Heat the matrix to 100°C and stir to melt to obtain a matrix liquid, which is then kept warm for later use.

[0074] The matrix is ​​composed of solid paraffin, liquid paraffin and white vaseline in a mass ratio of 1:3:16.

[0075] (4) Add the oil-soluble active ingredient to the matrix liquid of step (3), keep warm and stir evenly, cool to 40-50°C, add microcapsules and stir at 500 rpm for 30 seconds, can while hot, and then place at 5°C for rapid cooling to obtain the compound menthol ointment.

[0076] Among them, the oil-soluble active ingredients are composed of methyl salicylate, eucalyptus oil, clove oil and rose essential oil in a mass ratio of 80:60:1:2.

[0077] A compound menthol ointment, calculated based on a total weight of 1000g, is composed of the following raw materials by weight:

[0078] Menthol 100g, camphor 90g, wall material 95g, oil-soluble active ingredient 250g, matrix: the rest.

[0079] Example 4

[0080] The difference from Example 1 is that camphor microcrystals are not added in step (2).

[0081] A compound menthol ointment, calculated based on a total weight of 1000g, is composed of the following raw materials by weight:

[0082] Menthol 100g, wall material 71g, oil-soluble active ingredient 270g, matrix: the rest.

[0083] Example 5

[0084] The difference from Example 1 is that the wall material is composed of sodium starch octenylsuccinate and maltodextrin in a mass ratio of 60:10.

[0085] Example 6

[0086] The difference from Example 1 is that the mass ratio of microcrystals to wall materials is 0.8:1.

[0087] Example 7

[0088] The difference from Example 1 is that the mass ratio of microcrystals to wall materials is 2:1.

[0089] Example 8

[0090] The difference from Example 1 is that in the process of preparing microcapsules in step (2), the menthol microcrystals with an average particle size of 2.4 μm are replaced by menthol microcrystals with an average particle size of 1.5 μm prepared in Example 2; and the camphor microcrystals with an average particle size of 1.4 μm are replaced by camphor microcrystals with an average particle size of 1.1 μm prepared in Example 2.

[0091] Example 9

[0092] The difference from Example 1 is that, in the process of preparing microcapsules in step (2), the menthol microcrystals with an average particle size of 2.4 μm are replaced by menthol microcrystals with an average particle size of 3.7 μm prepared in Example 3; and the camphor microcrystals with an average particle size of 1.4 μm are replaced by camphor microcrystals with an average particle size of 1.6 μm prepared in Example 2.

[0093] Comparative Example 1

[0094] A method for preparing a compound menthol ointment comprises the following steps:

[0095] (1) Menthol was dissolved in anhydrous ethanol to obtain a menthol organic phase with a concentration of 0.25 g / mL. The menthol organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 h. The mixture was then filtered to obtain menthol microcrystals with an average particle size of 2.4 μm. The volume ratio of the menthol organic phase to pure water was 1:10.

[0096] Camphor was dissolved in anhydrous ethanol to obtain a camphor organic phase with a concentration of 0.3 g / mL. The camphor organic phase was then added dropwise to pure water at a rate of 2 mL / min. After completion of the addition, the mixture was allowed to stand at room temperature for 24 hours. Camphor microcrystals were obtained by filter pressing, with an average particle size of 1.4 μm. The volume ratio of the camphor organic phase to pure water was 1:10.

[0097] (2) Heat the matrix to 100°C and stir to melt to obtain a matrix liquid, which is then kept warm for later use.

[0098] The matrix is ​​composed of solid paraffin, ozokerite and white vaseline in a mass ratio of 85:1:180.

[0099] (3) Add the oil-soluble active ingredient to the matrix liquid of step (2), keep warm and stir evenly, cool to 40-50°C, add menthol microcrystals and camphor microcrystals, stir at 500 rpm for 30 seconds, can while hot, and then place at 5°C for rapid cooling to obtain the compound menthol ointment.

[0100] The oil-soluble active ingredient is composed of methyl salicylate, eucalyptus oil and turpentine in a mass ratio of 90:50:2.

[0101] A compound menthol ointment, calculated based on a total weight of 1000g, is composed of the following raw materials by weight:

[0102] Menthol microcrystals 80g, camphor microcrystals 120g, oil-soluble active ingredients 270g, matrix: the rest.

[0103] Comparative Example 2

[0104] A method for preparing a compound menthol ointment comprises the following steps:

[0105] (1) Mix menthol and camphor, stir and melt at 40° C. to form a eutectic solution of menthol and camphor, and keep the mixture warm for use;

[0106] (2) Heat the matrix to 100°C and stir to melt to obtain a matrix liquid, which is then kept warm for later use.

[0107] The matrix is ​​composed of solid paraffin, ozokerite and white vaseline in a mass ratio of 85:1:180.

[0108] (3) Add the oil-soluble active ingredient to the matrix liquid of step (2), keep warm and stir evenly, cool to 40-50°C, add menthol and camphor eutectic solution and stir at 500 rpm for 30 seconds, can while hot, and then place at 5°C for rapid cooling to obtain the compound menthol ointment.

[0109] The oil-soluble active ingredient is composed of methyl salicylate, eucalyptus oil and turpentine in a mass ratio of 90:50:2.

[0110] A compound menthol ointment, calculated based on a total weight of 1000g, is composed of the following raw materials by weight:

[0111] Menthol microcrystals 80g, camphor microcrystals 120g, oil-soluble active ingredients 270g, matrix: the rest.

[0112] The physical properties of the products of the examples and comparative examples were tested using the following test methods:

[0113] (1) Average particle size of microcrystals: The particle size of microcrystals is tested in accordance with GB / T 19077.1. The average particle size refers to the number average particle size of microcrystals.

[0114] (2) Microscope test: The morphology of menthol microcrystals and camphor microcrystals was observed using an optical microscope.

[0115] Figure 1 The optical micrograph of menthol microcrystals (1a) and the actual picture of menthol raw material without recrystallization (1b) are shown. The large particles of menthol raw material are recrystallized into micron-sized menthol microcrystals by the method of the present invention, which is conducive to the dispersion of microcapsules as tiny solid particles in the ointment after coating.

[0116] (3) Sustained-release performance of microcapsules: A concentration standard curve of L-1-methyl-4-isopropylcyclohexanol-3-ol (chemical name of menthol) was established using GC-MS. The menthol microcapsules or uncoated menthol prepared in each specific embodiment were placed in a 40±2°C oven and heated for a period of time (t=0 min, 0.5 min, 1 min, 3 min, 5 min, 10 min). The microcapsules were taken out and ground and dissolved with methanol. The samples were then diluted and analyzed by GC-MS. The residual amount of menthol was calculated based on the concentration standard curve and the sample amount. The sustained-release performance was evaluated by the release rate: the release rate at time t = 1 - the residual amount of menthol at time t ÷ the residual amount of menthol at time 0.

[0117] Figure 2 The release rates of different menthol-containing samples at different times are shown in the figure. As can be seen from the figure, compared to uncoated menthol, the coated microcapsules release less over time, i.e., release more slowly, indicating that the microcapsules help slow the volatilization of menthol, thereby prolonging its medicinal effect and the cooling sensation. Furthermore, from Examples 1, 6, and 7, the mass ratio of microcrystals to wall material affects the sustained-release performance: the greater the amount of wall material used, the better the sustained-release performance. This can be regulated according to actual needs. From Examples 1, 8, and 9, the average particle size of the microcrystals also affects the sustained-release performance: the larger the average particle size of the microcrystals, the better the sustained-release performance.

[0118] (4) Thermosensitive performance of microcapsules: A concentration standard curve of L-1-methyl-4-isopropylcyclohexanol-3 (chemical name of menthol) was established using GC-MS. Then, menthol microcapsules or uncoated menthol were placed in an oven at different temperatures (T = 20°C, 30°C, 40°C, 50°C) and heated for 0.5 min. After being taken out, they were ground and dissolved with methanol. Then, the samples were diluted and analyzed by GC-MS. The residual amount of menthol was calculated based on the concentration standard curve and the sample amount. The sustained release was evaluated by the release rate. The release rate at temperature T = 1 - the residual amount of menthol at temperature T ÷ the residual amount of menthol at 20°C.

[0119] Figure 3 The release rates of different samples at different temperatures are shown in the figure. As can be seen from the figure, the wall materials of Examples 2 and 5 do not contain the temperature-sensitive agent polyethylene glycol 1000 vitamin E succinate, while the wall materials of Examples 1 and 3 do contain a temperature-sensitive agent. Therefore, the release rate of Examples 1 and 3 increases significantly when the temperature rises from 30°C to 40°C, indicating that the addition of the temperature-sensitive agent increases the temperature sensitivity of the wall material, enabling the microcapsules to release menthol rapidly at 30-40°C. The temperature-sensitive agent polyethylene glycol 1000 vitamin E succinate has a melting point of 37-41°C and is highly water-soluble. As a component of the wall material, it can provide the microcapsules with excellent temperature responsiveness.

[0120] (5) Skin feel test: A human test was conducted, and 20 volunteers aged 18 to 45 years who met the test requirements were selected as subjects (10 men and 10 women). 0.020±0.005g of the sample was applied to the flexor side of the forearm, and the sample was evenly applied in a circular area with a radius of 2 cm with two back-and-forth strokes using the index finger. The cooling sensation of different samples after 0h and 1h was felt, and the cooling sensation was ranked. The sample with the most cooling sensation was numbered 1, and the average of the numbers was used to obtain the score of the sample at 0h or 1h. The results are listed in Table 1.

[0121] Table 1

[0122] project Example 1 Example 4 Example 5 Comparative Example 1 Comparative Example 2 0h Cool feeling 3 4.4 4.6 1.8 1.2 1h cooling sensation 1.2 2.9 1.9 4.2 4.8

[0123] As can be seen from the table, over time, the ranking of cooling sensation varies greatly. At 0h, Comparative Example 1 and Comparative Example 2 can give the stronger cooling sensation of skin, but as time goes on, due to the volatilization of cooling ingredients camphor and menthol, cooling sensation gradually weakens, and because Embodiment 1 and 5 obtain sustained-release microcapsules by coating, therefore continuously release cooling ingredients, therefore after 1h, Embodiment 1 and Embodiment 5 become two samples that cooling sensation is strongest. The above description shows that the preparation method provided by the present invention can prolong the drug effect of menthol ointment. In addition, because embodiment 4 does not add camphor microcapsules, cooling ingredients reduce, so cooling sensation is poorer than 1.

[0124] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a compound menthol ointment, characterized in that: The steps include: (1) preparing microcrystals: dissolving a cooling ingredient in ethanol to obtain an organic phase; adding the organic phase to pure water, allowing it to stand for crystallization, and obtaining microcrystals after solid-liquid separation; the cooling ingredient comprises at least one of menthol and camphor; (2) preparing microcapsules: dispersing the microcrystals in an aqueous solution of the wall material, homogenizing, and spray drying to obtain microcapsules; (3) preparing the matrix: heating and melting the matrix to obtain a matrix liquid; (4) Preparation of compound menthol ointment: adding the oil-soluble active ingredient to the matrix liquid, stirring evenly while keeping warm, adding the microcapsules after cooling, stirring evenly, canning while hot, and cooling to obtain the compound menthol ointment; The particle size of the microcrystals is 0.5 to 20 μm, and the average particle size is 1 to 10 μm; The wall material includes a temperature-sensitive agent, sodium starch octenylsuccinate, and maltodextrin; the temperature-sensitive agent is polyethylene glycol 1000 vitamin E succinate.

2. The method for preparing the compound menthol ointment according to claim 1, wherein The mass percentage of the wall material in the aqueous solution of the wall material is 10% to 30%; and / or, the mass ratio of the microcrystals to the wall material is 0.8 to 2:1; and / or, the concentration of the cooling component in the organic phase is 0.2 to 0.3 g / mL; And / or, the volume ratio of the organic phase to pure water is 1:8-12.

3. The method for preparing compound menthol ointment according to claim 1, wherein The solid-liquid separation method is centrifugation or filter press; And / or, the spray drying temperature is 30-55°C.

4. The method for preparing the compound menthol ointment according to claim 1, wherein The matrix comprises at least one of paraffin wax, ozokerite, vaseline, zinc wax and lanolin; And / or, the oil-soluble active ingredient includes at least one of methyl salicylate, eucalyptus oil, turpentine oil, clove oil, rose essential oil, cinnamon oil, olive oil, thymol and silicone oil.

5. A compound menthol ointment, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

6. The compound menthol ointment according to claim 5, characterized in that Based on a total weight of 1000g, the compound menthol ointment is composed of the following raw materials by weight: 50-100g of menthol, 90-150g of camphor, 70-250g of wall material, 250-300g of oil-soluble active ingredient, and the rest as a matrix.

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