DESIGN, DEVELOPMENT AND EVALUATION OF UNIDIRECTIONAL BUCCAL TABLET OF RIZATRIPTAN BENZOATE
Prakash Siju*, Jalpa Paun, Moinuddin Soniwala, Jayant Chavda.
The buccal mucosa has been investigated for local and systemic delivery of therapeutic peptides and other drugs that are imperilled to first-pass metabolism or are unstable within the rest of the gastrointestinal tract. Rizatriptan Benzoate is subjected to first-pass effect; therefore, formulation of buccal-adhesive dosage form can avoid this effect. This paper describes the preparation of unidirectional mucoadhesive buccal tablet comprising a drug- containing mucoadhesive layer and a drug-free backing layer, by core in cup design. Tablets were obtained by direct compression. The mucoadhesive layer was composed of a mixture of drug and mucoadhesive polymer with release retardant polymer and the backing layer. A two factor, three level, full factorial design was used to optimize amount of Polycarbophil and amount of HPMC K4M so as to get desired mucoadhesion, swelling and rate of drug release. Higher levels of HPMC K4M in the experimental design batches exhibited higher in-vitro drug release in the initial hour while the Polycarbophil levels could be related to increase in mucoadhesive strength. Overlay plot comprising a region that satisfied the constraints for all the selected attributes was generated. Formulation containing 6.52% w/w of Polycarbophil and 10% w/w of HPMC K4M was found to be optimum. Checkpoint batches were also prepared to validate the evolved mathematical models. Korsmeyer-Peppas release kinetic model best fitted the optimized batch release profile which showed anomalous diffusion mechanism. It can be concluded that buccal route can be one of the alternatives available for administration of Rizatriptan Benzoate.
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