RP-HPLC METHOD FOR THE SEPARATION OF PARACETAMOL, TIZANIDINE, ACECLOFENAC, CHLORZOXAZONE: APPLICATION TO TIZANIDINE DETERMINATION IN TABLET DOSAGE FORM

New, rapid, precise, accurate and specific chromatographic method with UV detection was developed and validated for the separation of paracetamol, tizanidine, diclofenac and chlorzoxazone and applied for the determination of tizanidine in tablet dosage forms. RP-HPLC method was developed by using Welchrom C18 Column (4.6 mm i.d. X 250 mm, 5 µm particle size), Shimadzu LC-20AT Prominence Liquid Chromatography. The mobile phase constituted of Phosphate buffer (pH-6.65): acetonitrile (60:40, v/v).The flow rate was set to 1.0 mL/min with the responses measured at 280 nm using Shimadzu SPD-20A Prominence UV-Visible detector. The retention times of paracetamol, tizanidine, aceclofenac and chlorzoxazone were found to be 3.200 min, 3.593 min, 7.717 min and 8.857 min respectively. This method successfully separated all the fore mentioned drugs in less than 10 min. tizanidine was found to give linear response in the concentration range of 2-10µg/mL. Recovery studies were executed to ascertain the accuracy by standard addition method and average recovery was found to be 98.824 to 100.126 %.The limit of detection and limit of quantification were found to be 0.1761µg/mL and 0.5336µg/mL respectively. The proposed method is simple, economical, fast and hence can be applied for routine quality control analysis of tizanidine in tablet dosage form. It can also be extended for the determination of paracetamol, chlorzoxazone and aceclofenac