ANALYSIS OF FLUNARIZINE DIHYDROCHLORIDE IN PHARMACEUTICAL DOSAGE FORM BY ULTRAVIOLET SPECTROPHOTOMETRY AND ITS APPLICATION TO DISSOLUTION STUDIES

Flunarizine Dihydrochloride (FNZ) is a selective calcium entry blocker with histamine H1 blocking activity intended for the treatment of migraine, occlusive peripheral vascular disease and as an adjuvant in the therapy of epilepsy. Existing methods analyzed Flunarizine in bulk and pharmaceutical dosage forms either as single component or in binary mixture, its related impurities and its degradation products by chromatographic techniques and spectroscopic techniques including AUC methods. Only fewer techniques to analyze Flunarizine Dihydrochloride have been reported. Hence we focused on analysis of FNZ in its conventional tablet dosage form by UV spectrophotometry. FNZ was estimated in commercial tablets (Flunarin 5) by a simple, accurate, precise and economical validated method. Excellent linearity was established in the concentration range of 3- 15 mcg/ ml at λ_max of 253.20 nm using 0.1 M Hydrochloric acid as solvent (R²= 0.9995). The assay results were satisfactory (95.42 ± 0.1%). Precision, recoveries were good and within limits (%RSD < 2.0). LOD and LOQ were 0.2471 mcg and 0.7489 mcg respectively. Further dissolution studies for FNZ tablets were carried out using rotating paddle apparatus with 0.1M Hydrochloric acid as dissolution medium pertaining to the ease of applicability of the developed method. These studies provide scope for analyzing FNZ in different pharmaceutical dosage forms and by varied analytical approaches.

Key words: Flunarizine Dihydrochloride, Method development, Validation, Dissolution.