Stability-indicating RP-HPLC method development and validation for simultaneous estimation of Cinnarizine and Piracetam bulk and in capsule dosage form

Abstract

This work presents the development and validation of a solid Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method for concurrently quantifying Cinnarizine and Piracetam in pharmaceutical formulations. The technique used an Agilent 1200 series high-performance liquid chromatography (HPLC) machine equipped with a C18 column. The mobile phase composition consisted of Methanol and Orthophosphoric Acid. Correlation coefficients of 0.9992 for Cinnarizine and 0.9998 for Piracetam indicate the calibration curves exhibit a robust linear relationship. The present investigation determined the Limits of Detection (LOD) for Cinnarizine to be 0.1575 µg/ml, other than for Piracetam it was found to be 1.9926 µg/ml. The Limits of Quantification (LOQ) for both compounds were found to be 0.4774 µg/ml and 6.0384 µg/ml, respectively. In interday precision tests, the approach exhibited a high level of accuracy, as evidenced by % Relative Standard Deviation (RSD) values of 0.3601 for Cinnarizine and 0.7080 for Piracetam. Assay results for Phescetam capsules revealed 100.53% purity for Cinnarizine and 100.19% for Piracetam, with % RSD values within acceptable limits, indicating high accuracy and precision. The method proved robust and rugged, showing consistent results under varying analytical conditions and across different analysts. Stability studies confirmed the method's suitability for routine quality control, with both drugs demonstrating stability under acidic, basic, oxidative, and photolytic conditions.