DISSOLUTION METHOD VALIDATION OF A COMBINED PARACETAMOL, IBUPROFEN, AND CAFFEINE CAPSULE DOSAGE FORM USING RP-HPLC

The objective of this research is to design and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the concurrent quantification of Paracetamol (350 mg), Ibuprofen (200 mg), and Caffeine (40 mg) within a capsule formulation. This fixed-dose combination (FDC) is frequently utilized for treating pain and fever due to the synergistic action of its constituents. Dissolution testing employed the USP Apparatus I (basket method), using 900 mL of phosphate buffer (pH 6.8) as the dissolution medium. The chromatographic separation was carried out on an Inertsil ODS-3V C18 column (150 × 4.6 mm, 5 μm), applying a gradient mobile phase of phosphate buffer (pH 3.0) and acetonitrile at a flow rate of 1.0 mL/min, with detection at 230 nm. Method validation was performed as per ICH Q2(R1) standards, assessing parameters such as specificity, linearity, accuracy, precision, robustness, solution stability, and filter compatibility. The method demonstrated excellent linearity (R² ≥ 0.999) over the specified ranges. Recovery for all analytes ranged between 98–102%, and system suitability and precision %RSD values were within ≤ 2%. Robustness testing confirmed method consistency under variable conditions, and solution stability was retained up to 48 hours. Hence, this RP-HPLC method proves to be effective and appropriate for routine quality control and dissolution evaluation of Paracetamol-Ibuprofen-Caffeine capsule formulations.