Validated rp-hplc method for simultaneous estimation of cabotegravir and rilpivirine in tablet dosage form

A simple, efficient, and time-saving reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous estimation of Cabotegravir and Rilpivirine in tablet dosage form. The method is rapid, precise, sensitive, and reproducible, making it suitable for routine analysis. Chromatographic separation was performed using a Waters Alliance e2695 system equipped with a Waters XBridge Phenyl column (150 × 4.6 mm, 3.5 ?m). The mobile phase consisted of ammonium formate buffer (pH 3.5, adjusted with formic acid) and acetonitrile in a 70:30 v/v ratio, delivered at a flow rate of 1.0 mL/min. Detection was carried out at 269 nm using a photodiode array (PDA) detector at ambient temperature. The method demonstrated acceptable system suitability parameters, with the number of theoretical plates for both analytes not less than 2000 and tailing factors not exceeding 2. The relative standard deviation (RSD) of peak areas was consistently below 2.0%, indicating good repeatability. Method validation was conducted following ICH guidelines, confirming that the method is accurate, precise, robust, and cost-effective for the quantitative determination and stability analysis of Cabotegravir and Rilpivirine in pharmaceutical formulations.