FORMULATION AND EVALUATION NASAL IN SITUGEL OF RIZATRIPTAN

Abstract

Rizatraptan, a 5-HT antagonist is an anti migraine drug. Rizatriptan undergoes hepatic first pass metabolism, hence it shows poor bioavailability. In this study attempt has been done to improve bioavailability by formulating nasal 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 gel was formulated by using 2 factor (i.e.% of carbopol 934P and % of poloxamer 407) 3 level center composite design. All the formulated design point formulations exhibit thermo reversible gelation property. Gels were characterized by permeation studies, pH, % drug content, mucoadhesive force, gel strength, in vitro diffusion, ex vivo diffusion, stability study. Rheological study of gel formulation indicated that increase in polymer concentration increases the viscosity, gel strength was found in range of 110-130 sec., Spectral study revealed no interaction between drug and polymer. Various responses like T50%(Y1), T(80%Y2), ‘n’ of peppa’a equation(Y3), ‘k’ of first order and ‘n’ of higuchi (Y5) were analyzed to obtain optimized formulation. Optimized formulation(OF) followed first order drug diffusion and theoretically obtained drug release profile for 8 Hr. on the base of dose calculation Stability study indicates that there was no significant change in the Rizatriptan benzoate. Rizatriptan benzoate formulated as bioadhesive solution for nasal administration could have potential to avoid first pass effect than oral route, thus improve bio availability of drug and as a safe and sustained release nasal delivery system to control migraine.