Oxidative Degradation Kinetic Study of Thiocolchicoside using Stability Indicating High Performance Thin Layer Chromatographic Method
Stability indicating HPTLC method was developed using aluminium plates precoated with silica gel 60 F254 as the stationary phase and toluene: acetone: water (1.5:7.5:1.0, v/v/v) as mobile phase with detection wavelength 370 nm. Thiocolchicoside was subjected to degradation in alkaline, acidic, oxidative, neutral, dry heat and photolytic conditions. Linearity was observed in the concentration range 100-500 ng/spot with correlation coefficient (R2) 0.9979 and 0.9960 at 370 nm. The developed method was validated for specificity, accuracy, precision, LOD and LOQ as per ICH guideline. The proposed method was successfully applied for the estimation of thiocolchicoside in pharmaceutical dosage forms and assay results was found to be in good agreement with labeled claim of pharmaceutical dosage forms of thiocolchicoside. The proposed method was also applied for degradation kinetic study of thiocolchicoside in 0.5, 1.0 and 1.5% H2O2 at different temperatures. The degradation of thiocolchicoside in all acidic conditions was found to be first order and highest degradation was found in 3.0 N HCl at 80°C temperature. The prediction of degradation rate constant was also done at different temperature and strengths of HCl using Design Expert software–9. The degradation products of thiocolchicoside formed in acidic medium were isolated and characterized using IR, Mass and NMR spectroscopy.