1. Properties: This product is milky white or yellowish, uniform and delicate O/W cream. It meets the requirements for ointment in the 2005 edition of “Chinese Pharmacopoeia”.
2. Identification: Take an appropriate amount of this product, equivalent to 500 mg of monobenzone, into a centrifuge bottle, add 100 ml of water, shake until the cream is completely dispersed, centrifuge, gently pour out the substances floating on the surface, and wash the filter residue with water , centrifuged again, and decanted the aqueous layer. Transfer the residue to a separatory funnel, add chloroform to adjust the volume to about 100 ml, shake, separate the chloroform layer, and filter with cotton gauze. Transfer the filtrate to a 150 ml flask, evaporate and recover chloroform in a ventilated place, add 5 ml of pyridine and 3 ml of anhydrous acetic acid to the dry residue, reflux the flask for 10 min, cool, then add 100 ml of water and 6 ml of acetone , Seal the flask, and cool it in the refrigerator for 1 h. Separate the precipitate in a glass crucible, wash the precipitate with water until there is no residual pyrimidine smell, and dry the precipitate with phosphorus pentoxide for 16 h in a vacuum desiccator. Determination of the melting point of the precipitate should be 110 ~ 113 ℃ (acetate of monobenzone).
3. Inspection: It should comply with the relevant provisions of the “Chinese Pharmacopoeia” 2005 edition cream.
4. Content determination: chromatographic conditions EclipseXDB-C18 (150 mm × 4.6 mm, 5 μm) chromatographic column, column temperature 30 ° C, detection wavelength 292 nm, mobile phase: acetonitrile: water = 60: 40, flow rate 1.0ml/min , injection volume 10 μl
5. Sample stability and irritation test
1) Illumination test: put this product in a colorless glass container, put it under (4500 ± 500) Lx strong light, and take samples at 0, 1, 5 days to check the properties, melting time limit, content and other indicators. Results The color of each indicator of the sample was slightly darker and the content was slightly lower than that of 0 d, which indicated that the product was sensitive to light and should be stored away from light.
2) Accelerated test: Take 3 batches of cream and place them at (30 ± 2) ℃ and relative humidity (60 ± 5)% for 10 days, and examine their properties, contents, etc. at 0, 1, 5 and 10 days respectively. There was no significant change in any of the indicators compared with 0 d.
Irritation test: Take 10 healthy adult mice, male or female, body weight (20 ± 3) g, divide them into administration group and blank control group (blank matrix), shave off the back hair, and apply the ointment on the back of the mice After 24 hours, observe the local skin reaction. The results showed no redness and swelling on the back, and there was no significant difference between the two groups.
Since the cream contains 20% Monobenzone Cream, since Monobenzone Cream is a fat-soluble drug, the amount of other components in the oil phase should be appropriately reduced. The saponification product of stearic acid and triethanolamine is an O/W emulsifier, stearyl alcohol is used as an auxiliary emulsifier and lubricant, which can emulsify and absorb more water, glycerin is used as a humectant, and laurocapram is a colorless and odorless Liquid, with a greasy feeling in contact with the skin, non-irritating, non-toxic, can make the cream soft and easy to spread, and can also significantly enhance the speed of the drug passing through the stratum corneum of the skin and increase the concentration of the drug in the skin, so as to better exert its therapeutic effect It is a good penetration enhancer. The oil-in-water cream base is adopted, the preparation process is simple, the design is reasonable, the stability is good, no irritation, the clinical curative effect is good, and it is worthy of clinical popularization and application.