Development of Stability Indicating HPTLC Method for Racecadotril from Bulk Drug and its Dosage FormAuthor(s): A. S. Gadekar, V. V. Pande, J. R. Rao and K. V. Shastri
A simple, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of racecadotril in bulk drug and its dosage form was developed and validated. The method employed Merck HPTLC aluminum sheets of silica gel 60F254 as the stationary phase. The solvent system consisted of chloroform : methanol (9.8 : 0.2 v/v). This system was found to give compact spots for racecadotril (Rf 0.61 ± 0.02). Racecadotril was subjected to acid and alkali hydrolysis, oxidation and photodegradation, and the degraded products were well separated from pure drug. Densitometric analysis of racecadotril was carried out in the remission - absorbance mode at 232 nm. The linear regression analysis data for the calibration plots showed good linear relationship with coefficient of regression value, r2 = 0.9994 in the concentration range of 100-1000 ng per spot. The mean value of correlation coefficient, slope and intercept were 0.9995 ± 1.88, 0.352 ± 0.02 and 5.205 ± 0.05, respectively. The limits of detection and quantitation were 200 and 600 ng per spot, respectively. The method was validated as per ICH guidelines for precision, recovery and robustness. Racecadotril samples on being degraded with hydrogen peroxide showed additional peaks at Rf 0.006 and 0.64 while the drug on being subjected to acidic and basic hydrolysis showed additional peaks at Rf 0.50 and 0.18, respectively. This indicates that the drug is susceptible to acid-base hydrolysis degradation, oxidation and photochemical degradation. Statistical analysis proves that the method is reproducible and selective for the estimation of the said drug. As the method could effectively separate the drug from its degradation product, it can be employed as a stability-indicating one.