Development and Validation of Stability Indicating High-Performance Liquid Chromatographic Method for Determination of Cyproheptadine Hydrochloride, its Impurity And Degradation Product.

This work presents a sensitive, accurate and selective RP-HPLC method for simultaneous determination of cyproheptadine HCl (CPH), its impurity B (dibenzosuberone) and CPH oxidative degradation product (10,11-dihydroxy-dibenzosuberone) in bulk powder and in pharmaceutical formulation. The RP-HPLC method depends on isocratic elution using C8 column and mobile phase consisting of 0.05 M KH2PO4 buffer:methanol (35:65, v/v, pH = 4.5) at a flow rate of 2 mL/min, and the eluant was monitored at 245 nm. Good resolution was obtained with tR values of 3.05, 7.54 and 6.17 min for CPH, impurity and oxidative degradate, respectively. The proposed method has been validated as per ICH guidelines using pure forms of CPH, its impurity and degradation product in pharmaceutical formulation with an accuracy of 100.48, 100.16 and 100.11, respectively. Additional spiking experiments yielded an accuracy of 100 ± 1.6%. Repeatability and intermediate precision results indicated acceptable low <2% RSD values. Moreover, the developed method's statistical results were favorably compared to the previously reported method results regarding both accuracy and precision. The developed method can be applied for analysis of the three components in quality control laboratories.