Assay of tolbutamide

Assay of tolbutamide

1. Tolbutamide Assay of By, Pritesh Digambar Jawale 3 rd year (Pharma) Refference: IP 2007 (vol.3)

2. Tolbutamide C 12 H 18 N 2 O 3 S Mol.Wt . 270.4 Tolbutamide is 3-butyl-1-[(4-methylphenyl)sulphonyl]urea. Tolbutamide contains not less than 99.0 per cent and not more than 101.0 percent of C 12 H 18 N 2 O 3 S, calculated on the dried basis . Description A white, crystalline powder; almost odourless.

3. B . Boil 0.1 g with 8 ml of a 50 per cent v/v solution of sulphuric acid under a reflux condenser for 30 minutes. Cool in an icebath ; a crystalline precipitate of 4-toluenesulphonylamide is formed, which after recrystallisation from hot water and drying at 105º melts at 135º to 140º Identification A . Determine by infrared absorption spectrophotometry. Compare the spectrum with that obtained with tolbutamide RS or with the reference spectrum of tolbutamide .

4. Tests Appearance of solution . A 2.0 per cent w/v solution in 1 M sodium hydroxide is clear, and colourless. pH . 4.5 to 5.5, determined in a solution prepared by dissolving 2.0 g in 50 ml of carbon dioxide-free water by heating at 70º for 5 minutes, cooling rapidly and filtering. Heavy metals . 1.0 g complies with the limit test for heavy metals (20 ppm). Sulphated ash . Not more than 0.1 per cent. Loss on drying . Not more than 0.5 per cent, determined on 1.0 g by drying in an oven at 105º for 3 hours. Assay . Weigh accurately about 0.5 g and dissolve in a mixture of 40 ml of ethanol (95 per cent) and 20 ml of water . Titrate with . 1 M sodium hydroxide using phenolphthalein solution as indicator. 1 ml of . 1 M sodium hydroxide is equivalent to 0.02704 g of Tolbutamide Storage . Store protected from moisture.

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