LC determination of rofecoxib in bulk and pharmaceutical formulations

An isocratic reversed phase-liquid chromatographic (RP-LC) method has been developed for the determination and purity evaluation of rofecoxib in bulk and pharmaceutical dosage forms using photodiode array detection set at 225 nm. The method is simple, rapid and selective, The method is capable of de tecting all process intermediates and other related compounds, which may be present at trace levels in finished products. Hence the method is very use ful for process monitoring during the production of rofecoxib. Chlorophenyl methyl sulphone has been used as internal standard for the quantitative de termination of rofecoxib. The method is linear in the range of 125-500 mug. The precision for inter- and intra-day assay variation of rofecoxib is bel ow 1.6% relative standard deviation (R.S.D.). The accuracy determined as re lative mean error (R.M.E.) for the intra-day assay is within +/-2.0%. The d rug was extracted from tablets (Vioxx) using acetonitrile. The percentage r ecoveries from dosage forms were ranged from 98.2 to 102.6. (C) 2001 Elsevi er Science B.V. All rights reserved.