Development and Validation of Analytical Method for Estimation of Leflunomide in Bulk and their Pharmaceutical Dosage Form

The analytical method was developed for estimation of Leflunomide in bulk and their pharmaceutical dosage form. Stability indicating HPTLC method was developed and validated. A simple and accurate High Performance Thin Layer Chromatography method was developed using aluminium sheet precoated with silica gel 60 F254 & mobile phase n-Hexane: Ethyl Acetate (7:3 v/v). The detection wavelength was 271 nm. The method was validated as per ICH guidelines. The linearity was found to be 75-450 ng/band. The correlation coefficient of calibration curve was found to be 0.9985. The method was found to be accurate, precise, specific and robust according to ICH guidelines. The limit of detection (LOD) for Leflunomide was found to be 3.604 ng/band and the limit of quantification (LOQ) for Leflunomide was found to be 10.923 ng/ band. The proposed HPTLC method was successfully applied for the forced degradation study of Leflunomide in bulk and tablet dosage form. Forced degradation study was carried out in acidic condition- 1N HCl at (80±2°C) for 3 hrs, in basic condition- 0.01 N NaOH at room temperature for 3 hrs, in oxidative condition- 6% w/v H2O2 at (60±2°C) for 1 hour, in thermal condition at 80°C for 24 hours and in photolytic condition for 24 hours in UV light. Degradation products were well separated by proposed HPTLC method and the method was found to be specific according to ICH guidelines. The developed method can be used in routine analysis for estimation and for stability study assessment of Leflunomide in Pharmaceutical dosage form.