Validated Stability-Indicating HPLC Method For Simultaneous Determination of Carisoprodol, Paracetamol, And Caffeine in A Combined Dosage Tablet

Clinical evidence supports the efficacy of a combined formulation of Carisoprodol, Paracetamol, and Caffeine in symptom reduction. This study describes the development of a stability-indicating RP-HPLC method for the accurate quantification of CAR, PCM, and CAF within their tablet dosage form. The chromatographic separation was achieved on a HIBAR C18 column (250 x 4.6 mm, 5 µm) at ambient temperature using an isocratic elution mode. The optimized mobile phase consisted of Methanol: 0.025 M Potassium Dihydrogen Phosphate Buffer [40:60 v/v], delivered at a flow rate of 0.8 mL/min, with UV detection at 210 nm. Crucially, the optimized method effectively separated CAR, PCM, and CAF from degradation products generated under various forced degradation conditions, highlighting its stability-indicating capability. Validated in accordance with ICH guidelines, the method demonstrated linearity over the concentration ranges of 8.75-43.75 µg/mL for CAR, 16.25-81.25 µg/mL for PCM, and 1.6-8 µg/mL for CAF. The determined LOD and LOQ values were 0.246 µg/mL and 0.746 µg/mL for CAR, 0.501 µg/mL and 1.521 µg/mL for PCM, and 0.064 µg/mL and 0.196 µg/mL for CAF, respectively. Accuracy of the method was established, yielding ranges of 98.10-101.98% for CAR, 99.08-101.54% for PCM, and 98.13-101.88% for CAF. Subsequent application of the developed and validated method revealed the % purity of CAR, PCM, and CAF to be 100.38%, 100.10%, and 100.83%, respectively.