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

Key words: Nasal in-situ gel, Box Wilson Design