Formulation and evaluation of bilayered gastroretentable mucoadhesive patch for stomach-specific drug delivery

The aim of the present work was to develop and evaluate stomach-specific controlled release, gastroretentable mucoadhesive patch of lercanidipine HCl. This drug is essentially soluble in gastric pH range of 1- 4 and have a partition coefficient (log p-value) of 6.1; according to this concept, it has been decided to formulate the gastroretentive bioadhesive patch. The patch system consisted of a drug release rate controlling film, using the combination of Eudragit RSPO and RLPO; mucoadhesive film by using the combination of various hydrophilic polymers. Bilayered patch were made by using the selected batch of two films using the layering method and evaluated for the various parameters like in vitro swelling study, ex vivo mucoadhesive strength. Film was folded into a hard gelatin capsule, evaluated for in vitro drug release in pH 1.2 containing 0.2% (w/v) sodium lauryl sulphate (SLS), and in vivo bioavailability in rabbits. Patches could control the drug release up to 12 h, having mucoadhesion strength in the range of 4.05±0.4 N to 4.52±0.12 N. In vivo bioavailability results indicate that the gastroretentive patch system provides a novel way to retain the drug matrix for the longer period of time in a stomach, enhance drug absorption and thereby offer a promising strategy for gastroretentive mucoadhesive drug delivery for the lercanidipine HCl.