Abstract:
A simple, selective and rapid stability-indicating RP-HPLC coupled with a photodiode array detector method has been developed and validated for the simultaneous determination of simvastatin and niacin in a combined dosage form. The chromatographic separation of the two cholesterol lowering drugs was achieved by utilizing Inertsil CN, 5µm, 250 mm x 4.6 mm i.d. column (GL Sciences Inc, Tokyo, Japan), maintained at 30 °C throughout the analysis. The drugs were separated in isocratic elution mode with a mobile phase of 0.1% Acetic Acid buffer-methanol (50:50, v/v) at a flow rate of 1.0 mL/min. Both simvastatin and niacin compound were detected by UV-PDA at 237 nm.
The method was validated for forced degradation, linearity and range, accuracy, precision and robustness according to ICH guidelines. The linearity and range for niacin and simvastatin were 0.05 to 0.150 mg/mL (R2 > 0.9999) and 0.004 to 0.012 mg/mL (R2 > 0.9992), respectively. The assay mean recoveries observed for niacin and simvastatin were 99.36% and 99.93%, respectively. The precision of the method obtained was 99.66% for niacin and 99.34% for simvastatin with RSD less than 2%. The lower degree of RSD that obtained in robustness and intermediate precision has proven that the method is highly robust. The validated method can be very helpful in the quality control analysis of active pharmaceutical ingredient and pharmaceutical dosage form.
