Main efficacy and function of pharmaceutical grade salicylic acid

 Main functions and effects of pharmaceutical grade salicylic acid ShuiyangsuanSalicylic Acid This product is 2-hydroxybenzoic acid
.

The content of C7H6O3 shall not be less than 99.
5%
.

【Properties】This product is white fine needle crystal or white crystalline powder; odorless or almost odorless; the aqueous solution exhibits acid reaction
.

This product is easily soluble in ethanol or medium, soluble in boiling water, slightly soluble in medium and slightly soluble in water
.

Melting point The melting point of this product (general rule 0612) is 158～161℃
.

[Identification] (1) Take the aqueous solution of this product, add 1 drop of ferric chloride test solution, and it will show violet color
.

(2) The infrared light absorption spectrum of this product should be consistent with the control spectrum (spectrum set 57)
.

【Check】Relevant substances are determined according to high performance liquid chromatography (General Rule 0512)
.

Test solution: Take 0.
5g of this product, accurately weigh it, put it in a 100ml measuring bottle, add mobile phase to dissolve and dilute to the mark
.

　　Control solution: Precisely measure 1ml of the test solution, put it in a 50ml measuring bottle, dilute it to the mark with mobile phase, shake well, then precisely measure 1ml, put it in a 10ml measuring bottle, dilute to the mark with mobile phase, and shake well
.

　　Reference substance solution Take appropriate amount of 4-hydroxybenzoic acid reference substance, 4-hydroxyisophthalic acid reference substance and phenol reference substance, accurately weigh, dissolve in mobile phase and quantitatively dilute to make each 1ml containing about 4-hydroxyl A mixed solution of 5 μg of benzoic acid, 2.
5 μg of 4-hydroxyisophthalic acid, and 1 μg of phenol
.

　　Chromatographic conditions Use octadecylsilane-bonded silica gel as filler; use methanol-water-glacial acetic acid (60:40:1) as mobile phase; detection wavelength is 270nm; injection volume is 20μl
.

　　Determination method Precisely measure the test solution, the reference solution and the reference solution, inject them into a liquid chromatograph, and record the chromatogram to twice the retention time of the main component peak
.

　　If there is a chromatographic peak consistent with the retention time in the reference solution in the chromatogram of the test solution, the peak area should be calculated according to the external standard method.
The 4-hydroxybenzoic acid should not exceed 0.
1%, and the 4-hydroxyisophthalic acid should not exceed 0.
1%.
0.
05%, phenol should not exceed 0.
02%; other single impurity peak area should not be greater than 0.
25 times (0.
05%) of the main peak area of ​​the control solution; total impurities should not exceed 0.
2%
.

　　Residues on ignition shall not exceed 0.
1% (General Rule 0841)
.

　　Heavy Metals Take 1.
0g of this product, dissolve it in 23ml of ethanol, add 2ml of acetate buffer (pH3.
5), and check according to the law (the first method of General Rule 0821).
The heavy metal content should not exceed 10 parts per million
.

　　[Determination of content] Take about 0.
3g of this product, accurately weigh it, add 25ml of neutral dilute ethanol (neutral to phenolphthalein indicator solution) to dissolve, add 3 drops of phenolphthalein indicator solution, and use sodium hydroxide titration solution (0.
1mol/ L) Titration
.

Each 1ml of sodium hydroxide titration solution (0.
1mol/L) is equivalent to 13.
81mg of C7H6O3
.

　　【Category】Disinfectant and antiseptic
.

　　[Storage] Sealed and preserved
.

　　【Preparation】Salicylic acid ointment