Rao RM and Sastry CSP
One simple and sensitive procedure (UV spectophotometric method) for the assay of two drugs namely terbinafine hydrochloride and clarithromycin in pure form and formulations. This method involves the formation of ion-association complex between TRB or CAM and the picric acid. In order to establish the optimum conditions necessary for rapid and quantitative formation of coloured product with maximum stability and sensitivity, the author performed experiments by measuring the absorbance at λmax 350 nm of a series of solutions, varying one and fixing the other parameters in each case such as type, volume and concentration of acid, organic solvent used for extraction, ratio of organic phase to aqueous phase during extraction, shaking time and temperature. The variable parameters were optimized. The results were statistically validated.