Spectrophotometric determination of oxiconazole in topical lotion using methyl orange.

A spectrophotometric method is described for the determination of oxiconazole in raw material and in topical lotion. This method is based on the reaction of the oxiconazole with methyl orange in buffered aqueous solution of citric acid at pH 2.3. The chromogen, being extractable with dichloromethane, could be measured quantitatively with maximum absorption at 427 nm. The Lambert-Beer law was obeyed in the concentration range of 4.0-14.0 microg ml(-1). A prospective validation of the method showed that the method was linear (r=0.9995), precise (intra-day: CV=1.57% and inter-day: CV=1.50%) and accurate (mean recoveries: 99.69%). The results compared favourably with those of the HPLC method.