Acetaminophen CAS:103-90-2

1. Overview

1. Product name: Acetaminophen    

2. Molecular formula: C ₈ H ₉ NO ₂            Molecular weight: 151.16

3. Structural formula:

2. Characters :

This product is white crystal or crystalline powder; odorless.

This product is easily soluble in hot water or ethanol, soluble in acetone, and slightly soluble in water.

The melting point  (General Principle 0612) is 168～172℃.

3, identification:

Add the test solution of ferric chloride to the aqueous solution of this product, and it will appear blue-violet.

Take about this product 0.1g of , add 5ml of dilute hydrochloric acid, heat in a water bath for 40 minutes, let cool; take 0.5ml, add 5 drops of sodium nitrite test solution, shake well, dilute with 3ml of water, add alkaline β-naphthalene 2ml of phenol test solution, shake it, it will appear red.

The infrared light absorption spectrum of this product should be consistent with the control spectrum (spectrum set 131).

4, check:

1. Acidity: Take 0.10g of this product, add 10ml of water to dissolve it, and measure it according to law (General Rule 0631). The pH value should be 5.5-6.5.

2. The clarity and color of the ethanol solution: Take 1.0g of this product, add 10ml of ethanol to dissolve, the solution should be clear and colorless; if it appears turbid, compare with No. 1 turbidity standard solution (General Rule 0902 First Method), no change Concentrated; if the color develops, it should not be deeper than the brown-red No. 2 or orange-red No. 2 standard colorimetric fluid (General Rule 0902 Method 1).

3. Chloride: Take 2.0 g of this product, add 100ml of water, heat to dissolve, cool, filter, take 25ml of filtrate, check according to law (General Rule 0801) and compare with the control solution made of 5.0ml of standard sodium chloride solution. Concentrated (0.01%).

4. Sulfate: Take 25ml of the remaining filtrate under the chloride item and check it according to the law (General Rule 0802). Compared with the control solution made of 1.0ml standard potassium sulfate solution, it should not be more concentrated (0.02%).

5. Para-aminophenol and related substances: new system for temporary use. Take an appropriate amount of this product, accurately weigh it, and add a solvent [methanol-water (4:6)] to make a solution containing about 20mg per 1ml as the test solution; take an appropriate amount of para-aminophenol reference substance and accurately weigh it. Add the above solvent to dissolve and make per containing 1ml about p-aminophenol a solution 0.1mg of as the reference solution ; accurately measure each of the reference solution and the test solution 1ml , put them in the same 100ml measuring flask, and dilute with the above solvent To the mark, shake well, as a control solution. According to high performance liquid chromatography (General Principle 0512) test. Use octyl silane bonded silica gel as filler; use phosphate buffer (take disodium hydrogen phosphate 8.95g, sodium dihydrogen phosphate 3.9g, add water to dissolve to 1000ml, add 10% tetrabutylammonium hydroxide solution 12ml)-methanol (90:10) is the mobile phase; the detection wavelength is 245nm; the column temperature is 40℃; the number of theoretical plates is not less than 2000 based on the paracetamol peak, and the resolution of the paraaminophenol peak and the paracetamol peak should be consistent Require. Precisely measure 20μl each of the control solution and the test solution, and inject them into the liquid chromatograph respectively. Record the chromatogram until the retention time of the main peak is 4 times. If there is a chromatographic peak consistent with the retention time of p-aminophenol in the test solution chromatogram, the peak area shall be calculated according to the external standard method, and the peak area of ​​p-aminophenol shall not exceed 0.005% ; the peak area of ​​other single impurities shall not be larger than the p-acetyl in the control solution The peak area of ​​aminophenol is 0.1 times (0.1%), and the sum of the peak areas of other impurities shall not be greater than 0.5 times (0.5%) of the peak area of ​​acetaminophen in the reference solution.

6. p-Chlorophenylacetamide: a new system for immediate use. Take the test product solution under the item of p-aminophenol and related substances as the test product solution; take the appropriate amount of p-chlorobenzeneacetamide reference substance and paracetamol reference substance, accurately weigh it, and add solvent [methanol-water (4 :6)] Dissolve and prepare containing per 1ml about chlorophenylacetamide 1μg of p- and acetaminophen a mixed solution 20μg of as a reference solution . According to high performance liquid chromatography (General Principle 0512) test. Use octyl silane-bonded silica gel as filler; use phosphate buffer (take disodium hydrogen phosphate 8.95g, sodium dihydrogen phosphate 3.9g, add water to dissolve to 1000ml, add 10% tetrabutylammonium hydroxide solution 12ml)-methanol (60:40 ) is the mobile phase; the detection wavelength is 245nm; the column temperature is 40℃; the number of theoretical plates is not less than 2000 based on the paracetamol peak, the resolution of the parachlorobenzene acetamide peak and the paracetamol peak Should meet the requirements. Precisely measure 20 µl each of the reference solution and the test solution, and inject them into the liquid chromatograph respectively, and record the chromatogram; calculated by the peak area according to the external standard method, the content of p-chlorophenylacetamide shall not exceed 0.005%.

7. Loss on drying: Take this product and dry it to constant weight at 105°C. The weight loss should not exceed 0.5% (General Rule 0831).

8. Residue on ignition: no more than 0.1% (general rule 0841).

9. Heavy metals: Take 1.0g of this product, add 20ml of water, heat in a water bath to dissolve, let cool, filter, take the filtrate, add 2ml of acetate buffer (pH3.5) and an appropriate amount of water to make 25ml, check according to law ( General Principle 0821 Law 1), the content of heavy metals shall not exceed 10 parts per million.

4. Microbial limit inspection: In accordance with the law (General Rule 1105 and General Rule 1106), the total number of aerobic bacteria in each 1g of the test product must not exceed 2000cfu, the number of molds and yeasts must not exceed 200cfu, and no Escherichia coli can be detected.

5. Assay:

Take about this product 40mg of , accurately weigh it, put it in a 250ml measuring bottle, add 50ml of 0.4% sodium hydroxide solution to dissolve it, add water to the mark, shake it, accurately measure 5ml, and place it in a 100ml measuring bottle. Add 10ml of 0.4% sodium hydroxide solution, add water to the mark, shake well, follow the UV-Visible spectrophotometry (General Rule 0401) , measure the absorbance at a wavelength of 257nm, according to C ₈ H ₉ NO ₂ the absorption coefficient of

 as calculated 715, which is obtained.

This product is calculated as dry product, and the content of C ₈ H ₉ NO ₂ should be 98.0%～102.0%

6. Inspection items and limits:

7. Packaging form:

25Kg/bag, barrel, box, the inner packaging is medicinal low-density polyethylene bag, the outer packaging is (woven bag, cardboard drum, carton).

8. Storage:

sealed and preserved.

9. Validity period : 48 months.