THERMOREVERSIBLE, MUCOADHESIVE IN SITU GELLING FORMULATIONS FOR NASAL DELIVERY OF PROPRANOLOL HYDROCHLORIDE

Mucoadhesive, thermoreversible propranolol hydrochloride formulations were made to overcome firstpass metabolism, to prolong the drug residence time in the nasal cavity and to improve the therapeutic efficacy. In situ gelling formulations were prepared by cold technique using Pluronic F-127, Pluronic F-68 / Polyvinyl Alcohol complex and Carbopol 934P as the mucoadhesive polymer. Formulations were so modulated as to have gelation temperature below 340C to ensure gelation at the physiological temperature after intranasal administration. Gelation was characterized by physical appearance as well as by rheological evaluation. The gelation temperature decreased with increase in Carbopol concentration, whereas mucoadhesive force increased. The formulations displayed a thixotropic behaviour. The pH of the nasal gels was found to be in the range of 5.3 to 5.6 very much ideal for nasal delivery. The results of in vitro drug diffusion studies across the sheep nasal mucosa indicated that the drug release increased with increase in Carbopol concentration. The release was found to be matrix diffusion controlled and occurred by Fickian mechanism. It could be concluded that, the mucoadhesive, in situ gelling formulations of propranolol hydrochloride proved to be physically stable, convenient, effective nasal delivery systems ensuring prolonged nasal residence and assuring enhanced absorption.