Rilpivirine and Dolutegravir Simultaneously Measured via RP-HPLC-PDA with Box–Behnken Design Application: A Study of Forced Degradation under Various Conditions

Abstract

Simultaneous estimation of rilpivirine (RLVN) and dolutegravir (DTGR) in bulk and tablet dosage forms via RP-HPLC-PDA with a Box–Behnken design (BBD) has been performed in this study to develop a fast, precise, timely and cost-saving method for estimating RLVN and DTGR in bulk and tablet dosage forms. The chromatographic conditions were optimized via the BBD, and the developed method was validated according to the ICH guidelines. Additionally, forced degradation studies were also conducted. RLVN and DTGR peaks were observed at retention times of 2.167 and 2.716 min, respectively, in a 6-min runtime. Kromasil 150 mm× 4.6 mm, 5 µm C 18 column was used. The flow rate of the mobile phase was 1.0 mL/min at a temperature of 30 °C. The mobile phase composition was a 0.1% OPA buffer and acetonitrile (ACN) in a 60:40 ratio. Elutes were measured at 260 nm (max) after being injected in a sample volume of 10 µL. The assay result of the marketed tablet was 99.19% and 99.09% for RLVN and DTGR, respectively. The results of forced degradation studies in different chemical environments conditions such as acid, base, dry heat, photo-stability, neutral, and oxidation conditions were observed for RLVN (5.96, 4.79, 3.27, 2.36, 0.99, and 4.35 in percentage degradation) and DTGR (5.67, 4.44, 4.09, 1.81, 0.43, and 4.28 in percentage degradation). The results of the validation parameters were within an acceptable range. The newly formed RP-HPLC-PDA method is novel, fast, precise, time-saving, and cost-effective.