A VALIDATED, STABILITY-INDICATING HPLC METHOD FOR THE DETERMINATION OF FELODIPINE AND ITS RELATED SUBSTANCES

An HPLC method was developed and validated to determine felodipine and related substances. A C18 column (5μm, 250 ×4.6 mm) was used for the separation at room temperature, with methanol: acetonitrile: water (50:15:35%, v/v/v) as the mobile phase at the flow rate of 1.0mLmin⁻¹. The detection wavelength was 238 nm. The validation characteristics included accuracy, precision, specificity, linearity, and robust, and stability-indicating. The method showed good linearity for felodipine and its related substances with correlation coefficients in the range of 5.05-40.4μg/mland 0.31-15.50μg/ml. Method accuracy was assessed for felodipine and its related substances at three levels, the recovery ranged from 98.86 to 101.03%. The intermediate precision were 0.42% for felodipine and was 1.01% for the related substances (n = 9). Limit of detection and quantification for felodipine and its related substances were 1 and 4ng, respectively. The solution remains stable within eight hours at room temperature. Finally, the method was demonstrated to be robust, resistant to small variations of chromatographic variables. This method is fast, simple, can be used for direct determination of felodipine and its related substances in the pharmaceutical preparation.