Development and Validation of UV-Spectrophotometric Methods for Simultaneous Estimation of Tolperisone Hydrochloride and Diclofenac Sodium in Combined Tablet Dosage Form

Two simple, sensitive, precise and specific UV spectrophotometric methods for simultaneous estimation of tolperisone hydrochloride and diclofenac sodium in bulk and combined tablet dosage form have been developed using distilled water as solvent. Determination using the simultaneous equation method was at wavelength 261 nm and 276 nm. The Q –absorbance ratio method involved the formation of equation at 293.5 nm (isoabsorptive point) and at 261 nm (λmax of tolperisone hydrochloride). The linearity ranges for tolperisone hydrochloride and diclofenac sodium were 621 μg/ml and 2–7 μg/ml respectively. The accuracy of the methods was assessed by recovery studies and was found to be 100.28 ± 0.32 and 99.46 ± 0.31 for simultaneous equation method and 100.44 ± 0.18 and 99.44 ± 0.16 for Q absorbance ratio method for tolperisone hydrochloride and diclofenac sodium, respectively. Results of marketed formulation shows that these methods can be applied successfully to marketed formulation.