Abstract

Sachdev Ojas Nihal, Mannam A.A, Chandra Ikshan and Omkaar N.O

A rapid and sensitive RP-HPLC method with UV detection (260 nm) for routine analysis of leflunomide in a pharmaceutical formulation was developed. Chromatography was performed with mobile phase containing a mixture of acetonitrile and phosphate buffer (60:40, v/v) with flow rate of 0.8 ml min −1 . Quantitation was accomplished with internal standard method. The procedure was validated for linearity (correlation coefficient = 0.9999), accuracy, robustness and intermediate precision. Experimental design was used for validation of robustness and intermediate precision. Plackett- Burman design was used to screen the essential factors for optimization. To test robustness, three factors were considered; percentage v/v of acetonitrile in mobile phase, flow rate and pH; an increase in the flow rate results in a decrease of the drug found concentration, while the percentage of organic modifier and pH have no important effect on the response. For intermediate precision measure the variables considered were: analyst, equipment and number of days. The RSD value (0.93%, n = 24) indicated a good precision of the analytical method. The proposed method was simple; highly sensitive, precise, accurate and retention time less than 6 min indicating that the method is useful for routine quality control.