Optimization and Evaluation of In situ Nasal Gel of Donepezil Hydrochloride

Abstract

Introduction: The nasal route has been explored as a route of administration, due to the benefits it offers. The formulation in the form of in situ gel has been utilized for the local and systemic effect. This type of formulation first exists in sol form, but once they are administered, it undergoes gelation to form gel, and this approach can be used for successful drug delivery system. Methods: Thus, in the present study, formulation of in situ gel for nasal administration for donepezil hydrochloride (HCL), by the use of 32 factorial designs, to improve its nasal bioavailability, was developed by increasing its nasal retention time and arrive at an optimized formulation. The formulation was developed by the use of cold method, by incorporation of thermoreversible polymer poloxamer 407 and mucoadhesive agent tragacanth. The in situ gel was later evaluated for different parameters such as pH, gelation time gelation temperature, gel strength, drug content, mucoadhesion, viscosity, in vitro drug diffusion, and stability. Results: Based on results obtained, F5 formulation was found to be optimum. The concentration of 22.5% Poloxamer 407 with 0.07% tragacanth showed promising nasal drug delivery system for donepezil HCl, with enhanced residence time due to increase in viscosity and mucoadhesion characteristics. Conclusion: The use of in situ gel formulation thus can effectively and safely improve the nasal residence time and absorption of donepezil HCl.