Development and Validation of a Stability-Indicating HPTLC Method for the Estimation of Eszopiclone in Pharmaceutical Dosage Forms

Abstract

Objective: A simple, sensitive, selective, precise repeatable and stability-indicating high-performance thin layer chromatographic method was developed and validated for Eszopiclone in bulk drug and in formulation. Method: Silica gel 60 F-254, TLC precoated aluminium plates was used as the stationary phase for analyzing Eszopiclone and its degradation products, using mobile phase consisting toluene: ethyl acetate: methanol (6: 4: 2 v/v/v). Result: This mobile phase gave compact spots for Eszopiclone with Rf value of 0.52 ± 0.02. Eszopiclone was exposed to hydrolysis, oxidation, neutral and photolytic conditions for conducting stress degradation study. The peak of Eszopiclone and the degradation product was well resolved from each other with a significantly different Rf value. Densitometric estimation of Eszopiclone was performed at 304nm. A good linear plot was obtained in the concentration range of 150-300ng/spot. The method was validated for precision, accuracy (recovery) and robustness study. The limit of detection (LOD) and limit of quantitation (LOQ) was found to be 130ng/spot and 150ng/spot, respectively. Conclusion: The developed HPTLC method can separate Eszopiclone from its degradation products, hence stability studies can be performed using this method.