A validated stability indicating LC-MS compatible RP-HPLC assay and dissolution methods for marketed formulation Stribild
Objective: The prime objective of the current work is to develop a simple, rapid, efficient, economical and stability indicating LC-MS (liquid chromatography–mass spectroscopy) compatible RP - HPLC (reverse phase – high performance liquid chromatography) method for the analysis of emtricitabine (EMT), tenofovir disoproxil fumarate (TDF), cobicistat (COB) and elvitegravir (ELV) in bulk, marketed formulation (Stribild) and in In-vitro dissolution method. Method: The chromatography was achieved on Unisol C18 column (250 × 4.0 mm, 3 µ) with a mobile phase combination of acetate buffer (adjusted with dilute glacial acetic acid to pH 4) and acetonitrile in gradient mode at a flow rate of 1mL/min and the detection was performed at 260 nm using PDA (photo diode array) detector. Forced degradation studies were performed and the % degradation under various stress conditions was calculated. The developed RP-HPLC method was applied for Stribild tablets to study the dissolution profile. Results: The retention times for emtricitabine, tenofovir disoproxil fumarate, cobicistat and elvitegravir were 5.7, 12.1, 16.3 and 19.4 min respectively. The % degradation was below 20% which is within the limits. The percent drug release was found to meet USP specification, i.e. not less than 80% of amount of labeled drug EMT, TDF, COB and ELV dissolved in 30min. Conclusion: The method was validated as per ICH guidelines and all the validation parameters were within the compendial requirements. The proposed method can be successfully adopted for the analysis of Stribild tablets in pharmaceutical industries. Keywords: Stribild, emtricitabine, tenofovir disoproxil fumarate, cobicistat, elvitegravir