FORMULATION AND EVALUATION OF pH TRIGGER NASAL IN-SITU GEL OF LEVOCETIRIZINE HYDROCHLORIDE FOR LOCALIZED TREATMENT OF ALLERGIC RHINITIS

Objective: This dissertation work aimed to prepare Levocetirizine HCL (LCH) nasal in-situ gel, a second-generation antihistamine, to improve its retention time, sustain release, enhance the bioavailability, and avoid first-pass metabolism. Process: The in-situ nasal gel was prepared to consume Carbopol as a gelling agent, Hypromellose (HPMC) as a thickening or thickness-imparting agent, and buffering agents to maintain pH. An assessment was conducted to determine the solubility, pH, rheological characteristics, consistency of content, adhesive properties to mucous membranes, gel strength, in-vitro release characteristics, the kinetics of release date, isotonicity, and sterility of the sample. Results: All formulations had a clear appearance with good gelling capacity, and drug content was found to be >87%. The pH values of the formulations were found to be acceptable, ranging from 6.2 ± 0.10 to 6.4 ± 0.44, and no irritation of the mucosal membranes was observed. The shearing character was found between 200-1400 at pH 6.4 and 2000-5500 cps at pH 7.4 when measured at 20 rpm. They also showed adequate gel strength of 14 ± 0.35 and mucoadhesion values ranging from 854 ± 0.33 dynes/cm2 to 5517 ± 1.88 dynes/cm², as well as sustained drug release. Based on these results, the optimal concentration range for both polymer and stand was determined to be between 0.775 and 0.800 for all parameters. Therefore, it can be concluded that in-situ nasal gel of LCH is a promising drug delivery system that could enhance bioavailability by overcoming first-pass metabolism.