Stability-Indicating High-Performance Thin-Layer Chromatographic Method for Quantitative Estimation of Emtricitabine in Bulk Drug and Pharmaceutical Dosage Form

A simple, sensitive, precise, specific and stability indicating high-performance thin-layer chromatographic (HPTLC) method for the determination of emtricitabine both in bulk drug and pharmaceutical dosage form was developed and validated. The method employed aluminium plates precoated with silica gel G60 F254 as the stationary phase. The solvent system consisted of toluene : ethyl acetate : methanol (2 : 8 : 1, v/v/v). This solvent system was found to give compact spots for emtricitabine with value 0.26±0.01. Densitometric analysis of emtricitabine was carried out in the absorbance mode at 284 nm. Linear regression analysis showed good linearity (2=0.9997) with respect to peak area in the concentration range of 30–110 ng spot−1. The method was validated for precision, limit of detection (LOD), limit of quantitation (LOQ), robustness, accuracy and specificity. Emtricitabine was subjected to acid and alkali hydrolysis, oxidation, neutral hydrolysis, photodegradation and dry heat treatment. Also the degraded products peaks were well resolved from the pure drug with significantly different values. Statistical analysis proved that the method is repeatable and specific for the estimation of the said drug. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability indicating method.