Formulation Development and Evaluation of Thermoreversible Mucoadhesive In Situ Nasal Gel of Asenapine Maleate

Asenapine maleate is a new second-generation antipsychotic agent. It shows poor oral bioavailability due to extensive first pass metabolism in liver. Nasal in situ gel of Asenapine maleate was formulated to enhance its systemic bioavailability. In situ gel was prepared by cold method and optimized using 32 full factorial experimental design using Design Expert Software V9. In situ gel was optimized for amount of poloxamer-407 and concentration of HPMCK4M (independent variables) in order to achieve desired response of T90% Cumulative drug release, Mucoadhesive strength, and Gelation temperature (dependent variables). The experimental results of optimized in situ gel formulation demonstrated that in situ gel was viscous polymer based liquid that exhibits sol-to-gel phase transition on the nasal mucosal surface due to change in specific physico-chemical parameter like body temperature having gelation temperature of 37°C with mucoadhesive strength of 2.94 N, drug content was found to be 101.2 ± 1.16 % and T90% drug release was found to be 562.5 min (9.38 hrs) which was extended up to 12 hrs. The pH of the formulations was found to be between of 5.5-7, Isotonicity and Mucosa irritation test by Histopathology study for formulation was found to be isotonic and non-toxic. An accelerated stability study of optimized in situ gel batch was kept for 6 months showed no significant change in physicochemical characteristics. The developed formulation holds promising future due to reduction in dose and dosing frequency and thus reduces dose related side effects and improved patient compliance.