A simple, rapid and accurate high performance liquid chromatography method is described for simultaneous determination of diclofenac potassium and thiocolchicoside from bulk drugs and their combined pharmaceutical dosage form i.e. tablets. The separation of drug was achieved on Intersil ODS C18 (150 x 4.6 mm i.d.) with 5 μ particle size, column showed most favorable chromatographic pattern over the other columns. The mobile phase consisted of a mixture of buffer and acetonitrile (66:34 % (v/v)). The buffer was 0.01 M sodium dihydrogen phosphate solution and tiethylamine. The detection was carried out at wavelength 263 nm. The mixture of buffer and acetonitrile (66:34% v/v) was used as a diluent. The method was validated for system suitability, linearity, accuracy, precision, robustness, stability of sample solution. The method has been successfully used to analyze diclofenac potassium and thiocolchicoside from combined dosage form i.e. tablets.
