Design and Development of Mucoadhesive Acyclovir Tablet

The purpose of this study was to design and optimize an oral controlled release acyclovir mucoadhesive tablet, in term of its drug release and mucoadhesive strength. A 3² full factorial design was employed to study the effect of independent variables like Carbopol-934P and hydroxypropyl methylcellulose K100M, which significantly influence characteristics like swelling index, ex-vivo mucoadhesive strength and in-vitro drug release. Tablets were prepared by direct compression and evaluated for mucoadhesive strength and in-vitro dissolution parameters. In all the nine formulations studied, the exponent (n) varied between 0.5266 and 0.7110, showing non-fickian release behavior corresponding to coupled diffusion or polymer relaxation, resulting in a controlled and complete drug release up to 12 h. Both these polymers had a significant effect on the mucoadhesive strength of the prepared tablets, measured as the force of detachment against sheep gastric mucosa. Besides unraveling the effect of the two factors on the various response variables, this study helped in finding the optimized formulation with excellent mucoadhesive strength and controlled drug release. It can be concluded that by formulating mucoadhesive tablets of acyclovir, its complete release can be ensured prior to absorption window and hence the problem of incomplete drug release and erratic absorption could be solved by increasing the retention of drug in GIT for a longer duration.