Preparation method of minoxidil liniment

Abstract

The invention discloses a preparation method of minoxidil liniment. The preparation method comprises the following steps: uniformly mixing propylene glycol, absolute ethyl alcohol and about 40% purified water until no obvious layering exists, and finally adding minoxidil to stir and dissolve to obtain the minoxidil liniment. According to the preparation process provided by the invention, purified water and absolute ethyl alcohol can form a latent solvent, so that the solubility of minoxidil in a single auxiliary material is greatly improved, and subsequent preparation of the digoxin injection is facilitated.

Description

Technical Field

[0001] The invention belongs to the field of pharmaceuticals, and more specifically, relates to a method for preparing a minoxidil liniment. Background Art

[0002] Minoxidil, chemical name: 6-(1-piperidinyl)-2,4-pyrimidinediamine, 3-oxide, molecular formula: C9H 15 N5O, molecular weight: 209.25. Minoxidil is used as a potassium channel opener in clinical practice. It can directly relax vascular smooth muscle and has a strong dilation effect on arterioles, which reduces peripheral resistance and blood pressure, but has no effect on capacitance vessels, so it can promote venous return. At the same time, due to reflex regulation and positive frequency effects, it can increase cardiac output and heart rate, but does not cause postural hypotension.

[0003] Minoxidil is a white or off-white crystalline powder, slightly soluble in ethanol, slightly soluble in chloroform or water, very slightly soluble in acetone; and soluble in glacial acetic acid. Rapid dissolution of minoxidil is beneficial to improving production efficiency. Since ethanol contains hydroxyl groups, which are polar groups and are similarly soluble in water, especially hydroxyl groups can form hydrogen bonds with water molecules, which greatly increases the solubility of ethanol and water. Therefore, a certain proportion of purified water is mixed with anhydrous ethanol to reduce the dissolution time of minoxidil and reduce the risk of ethanol volatilization during the production process. Summary of the invention

[0004] The object of the present invention is to overcome at least one disadvantage of the prior art and provide a method for preparing minoxidil ointment.

[0005] The technical solution adopted by the present invention is: The invention provides a preparation method of minoxidil liniment: propylene glycol, anhydrous ethanol and about 40% purified water are mixed until no obvious stratification occurs, and finally minoxidil is added and stirred to dissolve, so as to obtain the minoxidil liniment.

[0006] The preparation method of the minoxidil liniment provided by the present invention specifically comprises the following steps: 1) First, stir propylene glycol, anhydrous ethanol, and about 40% purified water until no obvious stratification occurs; 2) Finally, add minoxidil and stir to dissolve to obtain a minoxidil solution. 3) Add water to the minoxidil solution of step 2 to make up to volume, and then fill and seal to obtain the minoxidil ointment.

[0007] In some examples, in step 1), the amount of propylene glycol used is 517.5 g / L, and the amount of anhydrous ethanol used is 237.3 g / L.

[0008] In some examples, the amount of 40% purified water used in step 2) is 66.7 g / L.

[0009] In some examples, the amount of minoxidil used in step 3) is 50 g / L.

[0010] In some examples, the dissolving temperature in step 3) is 20-30°C.

[0011] In some examples, the Chinese medicine solution in step 3) is filtered through a microporous filter with a pore size of 4 μm.

[0012] The beneficial effects of the present invention are: The invention provides a preparation process of a minoxidil liniment, which can quickly dissolve digoxin. Since ethanol contains hydroxyl groups, which are polar groups and are similar to water in solubility, especially hydroxyl groups can form hydrogen bonds with water molecules, which greatly improves the mutual solubility of ethanol and water. Therefore, a certain proportion of purified water is mixed with anhydrous ethanol, thereby reducing the dissolution time of minoxidil and reducing the risk of ethanol volatilization in the production process. DETAILED DESCRIPTION

[0013] The present invention provides a production process example to illustrate

[0014] Example 1

[0015] Weighing: According to the prescribed amount, weigh the prescribed amount of propylene glycol, anhydrous ethanol, anhydrous ethanol, and minoxidil respectively.

[0016] Add anhydrous ethanol, propylene glycol, and about 40% of purified water (purified water temperature 20℃~30℃) to the liquid preparation tank, stir for 5 minutes, add minoxidil raw material and continue stirring for 90 minutes until no insoluble matter is visible, add water to make up to 180L to obtain minoxidil solution.

[0017] The drug solution was filtered through a polyethersulfone microporous filter with a pore size of 0.4 μm.

[0018] The above is a further detailed description of the present invention, which should not be regarded as a limitation on the specific implementation of the present invention. For ordinary technicians in the technical field of the present invention, simple deduction or replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A method for preparing a minoxidil liniment, characterized in that: Propylene glycol, anhydrous ethanol and about 40% purified water are mixed until no obvious stratification occurs, and finally minoxidil is added and stirred to dissolve to obtain a minoxidil ointment.

2. The preparation method according to claim 1, characterized in that: The following steps are involved: 1) First, stir propylene glycol, anhydrous ethanol, and about 40% purified water until no obvious stratification occurs; 2) Finally, add minoxidil and stir to dissolve to obtain a minoxidil solution. 3) Add water to the minoxidil solution of step 2 to make up to volume, and then seal the solution to obtain the minoxidil ointment.

3. The preparation method according to claim 2, characterized in that: In the step 1), the amount of propylene glycol used is 517.5 g / L, and the amount of anhydrous ethanol used is 237.3 g / L.

4. The preparation method according to claim 2, characterized in that: The amount of 40% purified water used in step 1) is 66.7 g / L.

5. The preparation method according to claim 2, characterized in that: The minoxidil dosage in step 2) is 50 g / L.

6. The preparation method according to any one of claims 2 to 5, characterized in that: The dissolving temperature in step 1) is 20-30°C.

7. The preparation method according to any one of claims 2 to 5, characterized in that: In the step 3), the Chinese medicine solution is filtered through a microporous filter with a pore size of 4 μm.

8. The preparation method according to claim 7, characterized in that: The microporous filter selected was selected from polypropylene filters.