Simple Spectrophotometric Determination of Isoxsuprine Hydrochloride in Spiked Human Urine and in Tablets Using Folin-Ciocalteu’s Reagent

A very simple, rapid and cost effective spectrophotometric method is described for the determination of isoxsuprine hydrochloride (ISX). The method is based on the selective reduction of Folin-Ciocalteu’s reagent (F-C reagent) by phenolic and amino group present in ISX in alkaline medium to form a blue coloured chromogen which absorbs maximally at 770 nm. Beer’s law is obeyed in the concentration range 2.0-40.0 μg ml-1 with correlation coefficient, molar absorptivity and Sandell’s sensitivity values of 0.9993, 6.61x103 l mol-1 cm-1 and 0.0511μg cm-2, respectively. Various experimental variables were optimized to obtain reliable results. The method was successfully applied to the determination of ISX in spiked human urine, and in pharmaceutical formulations. The results of analysis of the pharmaceuticals tallied well with the label claim and were statistically compared with those of the official method by applying the Student’s t-test and F-test. The accuracy was further ascertained from spike-recovery method.