Estimation of Tolperisone Hydrochloride and Etodolac in Combined Dosage Form by UV-Spectrophotometric Methods

Two simple, sensitive, rapid, precise UV spectrophotometric methods have been developed and validated for simultaneous estimation of Tolperisone hydrochloride and Etodolac. Recently this combination was approved for treatment of acute muscle spasm in adults, in tablet dosage form, in ratio of 150mg: 400mg. First method is simultaneous equations method, wavelength selected for estimation of Tolperisone hydrochloride and Etodolac are 256 nm and 273 nm respectively. The second method is first order derivative method based on measurement at zero crossover point of another drug, measurement of Tolperisone hydrochloride and Etodolac were carried out at 246.7 nm and 255.2 nm respectively. The linearity was obtained in the concentration range of 3–10.5 μg/ml and 8–28 μg/ml of TOLP and ETD respectively. The proposed methods are successfully applied for the simultaneous determination of both drugs in commercial tablet preparation. The method was validated with respect to linearity, accuracy and precision as per the International Conference on Harmonization (ICH) guidelines.