Preparation and characterization of a novel once-daily formulation of diltiazem using arabinogalactan as a channeling agent

The aim of the present study was to develop a once‐daily, delayed controlled release formulation for diltiazem. Developed formulation consists of two coated tablets inserted into a capsule; the first tablet is intended to produce a fast release profile, while the second tablet with a unique controlling membrane containing arabinogalactan as a channeling agent was designed to achieve a delayed controlled release profile for diltiazem. The in vitro characteristic of formulation was determined in terms of the surface morphology of the coated tablet, and the impact of the different polysaccharide in coating on the dissolution and in vitro drug release. Arabinogalactan was found to be most appropriate channeling agent to control in vitro drug release. When tested in buffer (pH 6.8) the formulation produced a desired delayed controlled release dissolution profile for over 24 h. Surface morphology of the coating film clearly demonstrated channeling formation on contact with the media. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012