Formulation And Development Of Nasal In-Situ Gel Of Rizatriptan For Treatment Of Migraine

Abstract

Rizatriptan is a selective 5-HT1B and 5-HT1D receptor agonist that is used to treat migraines. As the plasma half- life of rizatriptan is 2-3 hrs. There is need to increase its bioavailability by incorporating it in suitable drug delivery system. Nasal in situ gel drug delivery systems have ability to directly target the central nervous system while avoiding the blood-brain. Thus this study aims at formulation and development of nasal in-situ gel of rizatriptan for treatment of migraine. Formulation and evaluation of rizatriptan was performed according to standard protocol. Results showed that all the formulations of in situ gel was observed to be transparent. The clarity of gel was observed from F1-F4 while in case of F5 and F6 the gel turned out to be slightly hazy. All the fromulations were viscous as the gel should be without absence of any specific odor.  The viscosity among the solution ranged from 936 to 1325 cps while in case of gel the viscocity spanned from 1565 to 2236. The highest mucoadhesive strength was seen to be 74.1 dyne/cm² in F6 formulation.  The maximum drug content of 99.65% was associated with F3 formulation. Further the gelation temperature varied from 37.12 to 42.23 and accordingly the gel strength varied from 8.5 seconds to 16.4 seconds.  As the gelation temperature of F4 is near to body temperature it can be considered as optimized formulation. The % Cumulative Drug Release data suggested that in F4 formulation the maximum drug release of 99.12 % is achieved. From the regression analysis of F4, the R² value for zero order and first order was determined as 0.949 and 0.855 respectively.  Thus, the release kinetics of in situ gel follows zero order release kinetics.  From results it can be concluded that nasal in situ gel will greatly boosts rizatriptan accumulation in the brain and may be a useful substitute for parentral and oral formulations