Spectrophotometric Determination of Nitrofurantoin Drug in its Pharmaceutical Formulations Using MBTH as a Coupling Reagent

Abstract

A direct, sensitive and efficient spectrophotometric method for the determination of nitrofurantoindrug (NIT) in pure as well as in dosage form (capsules) was described. The suggested method wasbased on reduction NIT drug using Zn/HCl and then coupling with 3-methyl-2-benzothiazolinonehydrazone hydrochloride (MBTH) in the presence of ammonium ceric sulfate. Spectrophotometricmeasurement was established by recording the absorbance of the green colored product at 610 nm.Using the optimized reaction conditions, beer’s law was obeyed in the range of 0.5-30 μg/mL, withgood correlation coefficient of 0.9998 and limits of detection and quantitation of 0.163 and 0.544μg/mL, respectively. The accuracy and precision of the proposed method represented by recovery andrelative standard deviation were satisfactory; about 99.33% and 1.16%, respectively. The proposedmethod was applied for determination of NIT in its pharmaceutical forms and the results comparedsuccessfully with those obtained by standard method (British pharmacopeia method).Keywords: Nitrofurantoin , MBTH , Oxidative coupling reaction.