www.wjpps.com Vol 8, Issue 8, 2019. 706 Valavi et al. World Journal of Pharmacy and Pharmaceutical Sciences FORMULATION DEVELOPMENT AND EVALUATION OF PAROXETINE HYDROCHLORIDE HEMIHYDRATE pH INDUCED IN- SITU NASAL GEL DRUG DELIVERY SYSTEM Manashi P. Valavi*, Sandip A. Tadavi, Azam Z. Shaikh and Sunil P. Pawar Department of Pharmaceutics, P. S. G.V. P. Mandal’s, College of Pharmacy, Shahada-425409 Dist.- Nandurbar, Maharashtra, Indai. ABSTRACT Paroxetine hydrochloride hemihydrate undergoes hepatic first pass, hence it shows poor bioavailability. In this study attempt has been done to improve bioavailability by formulating pH induced in-situ gel; formulation was developed to reduce the mucociliary clearance by using Mucoadhesive polymer in gel, thereby increasing the contact of formulation with nasal mucosa and hence improving the absorption of drug. The in situ gelation was achieved by the use of Carbopol 934, which exhibit pH induced gelation property and HPMC K4M, HPMC K15M was used as the mucoadhesive agent. Gels were prepared by previously reported cold technique and characterized by Gelation study, Gel strength, Permeation Studies, Histopathological Evaluation, pH, Drug Content, Rheological studies, drug polymer interaction, Stability study. In in-vitro drug release study was found 87.87-96.23%, pH of gel is in range of 5-5.9, drug content 91.30-97.13%. Rheological study of gel formulation indicated that increase in polymer concentration increases the viscosity, gel strength was found in range of 25-41 sec., Spectral study revealed no interaction between drug and polymer as there is no shifting of drug λ max. Stability study indicates that there was no significant change in the Paroxetine hydrochloride hemihydrate. Paroxetine hydrochloride hemihydrate formulated as bioadhesive pH induced solution for nasal administration could have potential to avoid first- pass effect than oral route, thus improve bioavailability of drug and as a safe and sustained release nasal delivery system to control depression. KEYWORDS: Nasal drug delivery, In Situ nasal Gel, Mucoadhesive, Formulation, WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES SJIF Impact Factor 7.421 Volume 8, Issue 8, 706-720 Research Article ISSN 2278 – 4357 *Corresponding Author Manashi P. Valavi Department of Pharmaceutics, P. S. G.V. P. Mandal's, College of Pharmacy, Shahada-425409 Dist.- Nandurbar, Maharashtra, Indai. Article Received on 23 May 2019, Revised on 12 June 2019, Accepted on 03 July 2019 DOI: 10.20959/wjpps20198-14215