Background: Meclizine hydrochloride (MCZ) is an antihistamine that is used as an antiemetic to prevent and cure nausea and vomiting. Because of its limited water solubility and first-pass metabolism, it exhibits variable absorption. Objective: To formulate and evaluate MCZ as an intranasal in situ gel with increased residence time and permeability. Methods: We made an inclusion complex of MCZ using various cyclodextrins as a complexing agent to help the drug dissolve better. The complexes were studied, and the ones that were better at dissolving were chosen to be used in the creation of an in situ gel with poloxamer 407 (17–20% w/v) and hyaluronic acid (0.25–0.75% w/v). Prepared formulas were subjected to various evaluation tests, and the optimum formula was subjected to an ex vivo permeation study. Results: Hydroxypropyl-cyclodextrin (HP-CD) complexation increased the solubility of MCZ. A prepared complex (10 mg of MCZ) was used for nasal in situ gel preparation. Formula (F3) containing 17% poloxamer 407 and 0.75% hyaluronic acid exhibited favorable characteristics, including optimal gelation temperature (33.33°C), drug content (100.51%), gel strength (35.0 seconds), spreadability (4.2 cm), and 98.52% in vitro drug release over 5 hours in simulated nasal fluid (pH 6.8), and provided considerably high permeability. Conclusions: A mucoadhesive in situ gel formulation of MCZ (HP-β-CD) is a promising nasal formulation for the management of nausea and vomiting.
