High-performance thin-layer chromatographic determination of etoricoxib and thiocolchicoside in combined tablet dosage form.

A new, simple HPTLC method for determination of etoricoxib (ETO) and thiocolchicoside (THIO) in combined tablet dosage form has been developed and validated. The pharmaceutical dosage form used in this study was Nucoxia-MR tablets. Sample solutions were prepared at concentrations of 25 and 20 microg/mL for ETO and THIO, respectively. The separation was carried out on 20 x 10 cm Merck aluminum sheets precoated with a 250 microm layer of silica gel 60F254 using ethyl acetate-methanol (8 + 2, v/v) as the mobile phase. The calibration curve was linear over a range of 50-250 and 100-500 ng/band for ETO and THIO, respectively. Quantitative determination was done by densitometric scanning of bands at 290 nm. LOD and LOQ values were 10.993 and 33.314 ng/band, respectively, for ETO and 25.133 and 76.161 ng/band, respectively, for THIO. The method was validated with respect to linearity, accuracy, precision, and robustness in accordance with the International Conference on Harmonization guidelines. The method has been successfully applied to the analysis of drugs in the pharmaceutical formulation.