The combination of aceclofenac, paracetamol and chlorzoxazone is emerging as one of the widely prescribed combination in single dosage form. Aceclofenac is a typical Cox-2 inhibitor in combination with muscle relaxant chlorzoxazone and a traditional antipyretic drug paracetamol. Literature revealed that there is no single method for the simultaneous estimation of all these drugs in tablet dosage forms, which prompted us to develop a simple, rapid, accurate, economical and sensitive spectrophotometric method. The simultaneous estimation method is based on the additivity of absorbances, for the determination of aceclofenac, paracetamol and chlorzoxazone in tablet formulation. The absorption maxima of the drugs found to be at 276 nm, 282 nm and 248 nm respectively for aceclofenac, chlorzoxazone and paracetamol in methanol. All three drugs obeyed the Beer Lambert’s law in the concentration range of 2-20 µg /ml. The accuracy and reproducibility of the proposed method was statistically validated by recovery studies.


Aceclofenac, Paracetamol and Chlorzoxazone in tablets.