A stability indicating novel analytical method for the determination of lamivudine and dolutegravir in bulk and its tablets using reverse phase high-performance liquid chromatography

Aim: A simple and sensitive analytical method was developed to simultaneously estimate lamivudine (LAM) and dolutegravir (DOL), anti-retroviral drug combination in bulk and dosage forms. Materials and Methods: Separation of analytes was done on a BEH Shield RP18 (2.1 mm × 100 mm × 1.7 mm, 5 μm Particle size) using sodium dihydrogen phosphate pH 4.9 adjusted with orthophosphoric acid: Methanol (60:40, %v/v) as mobile phase pumped at 1.0 ml/min. A photodiode array detector was used to find the detection wavelength at an isosbestic point of 292 nm while maintaining the column temperature at 30°C. With a total run period of 8 min, the mobile phase was utilized as a diluent. The International Council on Harmonization guidelines were followed in the method's validation. The method's capacity to indicate stability was confirmed by experiments on forced degradation. Results: LAM and DOL eluted at 2.88 and 3.83 min, respectively. Both the drugs exhibited excellent linearity between 105.00–315.00 and 17.50–52.50 μg/ml for LAM and DOL, respectively. The LOD and LOQ were found to be 4.51 and 15.03 μg/ml for LAM and 5.82 and 19.41 μg/ml for DOL, respectively, which are very minute concentrations. Conclusion: The method was therefore found to be quite sensitive. The proposed high-performance liquid chromatography technique was thereby sensitive, reproducible, accurate, and reliable for the measurement of LAM and DOL.