Development and validation of RP-HPLC method for simultaneous determination of diclofenac sodium and tizanidine hydrochloride in bulk and tablet formulation

A reverse phase high performance liquid chromatographic method (RP-HPLC) hasbeen developed for the simultaneous estimation of Diclofenac sodium (DICS), and Tizanidine Hydrochloride (TIZH) in the pharmaceutical formulation. The chromatographic column used was a reverse phase 4.6250 mm Hypersil C18 HPLC column with 5m (particles) packing. The mobile phase was ACN: Phosphate buffer pH 7.0 (50:50 v/v) delivered at a flow rate of 1.0 mL/min. The injection volume was 25 L. Elute was analyzed by a UV detector set at 220 nm .Linearity was obtained inthe concentration range of 2-10 μg/ml for DICS, 2.512.5 μg/ml Tizanidine hydrochloride. The method was statistically validated and RSD was found to be less than 2% indicating high degree of accuracy and precision of the proposed HPLC method. Due to its simplicity, rapidness, high precision and accuracy, the proposed RP-HPLC method may be used for determining Diclofenac Sodium and Tizanidine Hydrochloride in bulk drug samples.