Spectrophotometric determination of azathioprine in pharmaceutical formulations

• Published in: Talanta (Oxford) Vol. 47; no. 5; pp. 1279 - 1286
• Main Authors: Lakshmi, Chilukuri S.R, Reddy, Manda N
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.1998; Oxford Elsevier
• Subjects: Analysis; Azathioprine; Biological and medical sciences; Celestine blue; Chloramine-T; Cresyl fast violet acetate; Gallocyanine; General pharmacology; Medical sciences; N-1-naphthylethylene diamine; N-Bromosuccinimide; Nitrous acid; Pharmacology. Drug treatments; Spectrophotometry; Celestine blue; Azathioprine; Spectrophotometry; N-Bromosuccinimide; Chloramine-T; Nitrous acid; Gallocyanine; Cresyl fast violet acetate; N-1-naphthylethylene diamine; Diazotization; Dosage form; Colorimetry; Tablet; Immunosuppressive agent; Quantitative analysis
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/S0039-9140(98)00216-1

Four simple and sensitive visible spectrophotometric methods (A–D) have been described for the assay of azathioprine (ATP) either in pure form or in pharmaceutical formulations. Methods A and B are based on the oxidation of ATP with excess N-bromosuccinimide (NBS) or chloramine-T (CAT) and determining the consumed NBS or CAT with a decrease in colour intensity of celestine blue (CB) (method A) or gallocyanine (GC) (method B), respectively. Methods C and D are based on the diazotisation of reduced azathioprine (RATP) with excess nitrous acid and estimating either the consumed nitrous acid (HNO 2) with cresyl fast violet acetate (CFVA) (method C) or by coupling reaction of the diazonium salt formed with N-1-naphthyl ethylene diamine dihydrochloride (NED) (method D). All of the variables have been optimized and the reactions presented. The concentration measurements are reproducible within a relative standard deviation of 1.0%. Recoveries are 99.2–100.3%.