RP-HPLC Method Development and Validation for Simultaneous Estimation of Aspirin, Caffeine and Orphenadrine citrate in Tablet Formulation

A simple, precise and accurate RP-HPLC method has been developed and validated for the simultaneous estimation of a three component mixture - aspirin, caffeine and orphenadrine citrate. The chromatographic separation was achieved with methanol phosphate buffer (pH 3) in the ratio of 6535 (v/v) as mobile phase, on ACCLAIMTM 120 C18 column (5 m, 4.6 X 250 mm), at a flow rate of 1ml/m using isocratic elution. Detection was carried out at 215 nm. The retention time for aspirin, caffeine and orphenadrine citrate was found to be 4.2, 3.3 and 6.5 m respectively. The linearity range was found to be 10-100 g/ml for aspirin and 2-20 g/ml for both caffeine and orphenadrine citrate with r2 value 0.997, 0.994 and 0.997 respectively. The mean percent recovery was found to be 97.3-97.80 % for aspirin, 95-104.3 % for caffeine and 96.36-103.4 % for orphenadrine citrate.