Formulation and Evaluation of Mucoadhesive Buccal Tablets of Repaglinide

Abstract

Objective: Delivery of the desired drug as mucoadhesive drug delivery systems has been subject of interest since 1980s. The various advantages associated with these systems made the buccal drug delivery as a novel route of drug administration. Buccal region offers an attractive route for the administration of systemic drug delivery. The objective of the study was to develop mucoadhesive buccal tablets of repaglinide. Methodology: The tablets were prepared by wet granulation method using a combination of mucoadhesive polymers like chitosan, hydroxyethyl cellulose, guar gum and carbopol 934P in different ratios. Results: Buccal tablets were evaluated by different methods for parameters such as thickness, hardness, weight uniformity, drug content uniformity, surface pH, ex vivo mucoadhesive strength, ex vivo residence time, in vitro drug release, ex vivo drug permeation. The tablets were evaluated for in vitro release in phosphate buffer of pH 6.8 for 12 h. In order to determine the mode of release, the data was subjected to zero order, first order, Higuchi and Korsmeyer-Peppas model. The mucoadhesive strength was evaluated by measuring the force required to detach the tablets from sheep buccal mucosal membrane. Carbopol 934P showed maximum mucoadhesion and required maximum force for detachment; the force required for detachment was directly proportional to its content. DSC and XRD study of the pure drug indicated that the drug is in the crystalline form. But in the formulations, peaks indicated that the drug is in the amorphous form. FTIR spectroscopic studies indicated that there is no drug-excipient interaction. Conclusion: The prepared formulations showed good mucoadhesive strength and ability to sustain the drug release over 12 h; hence, these are the versatile drug delivery systems for repaglinide.