Development and validation of stability-indicating RP-HPLC method for the simultaneous determination of Citicoline and Nimodipine in bulk and tablets

Abstract

A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) approach was developed and validated for the simultaneous measurement of Citicoline and Nimodipine concentrations in tablet dosage forms. Chromatographic separation was accomplished by utilizing a C18 column filled with a mobile phase composed of methanol and phosphate buffer (pH 3.0) in a 60:40 proportion, delivered at a flow rate of 1.0 mL/min. Citicoline and Nimodipine exhibited excellent resolution, with retention durations of 3.006 minutes and 5.739 minutes, respectively. The method proved to be remarkably linear for both drugs over the concentration range of 100-350 µg/ml, with correlation values (r) of 0.9994 for Citicoline and 0.9997 for Nimodipine. Both Citicoline and Nimodipine had limits of detection (LOD) of 2.4714 µg/ml and 1.4600 µg/ml, respectively. The lower and upper limits of quantification were found to be 7.4893 µg/ml and 4.4242 µg/ml, respectively. The method exhibited robust performance with low %RSD values, ensuring precision and accuracy. Stability studies revealed that both drugs were stable under various stress conditions, with degradation percentages well within acceptable limits. The method that was developed was effectively used on commercial tablet formulations, therefore demonstrating its appropriateness for common quality control and stability testing in pharmaceutical analysis.