Abstract: Aqueous diffusion coating formulations suitable for use on pharmaceutical dosage forms comprising an admixture of an insoluble polymer component of a copolymer of ethylacrylate and methylmethacrylate and as a hydrophilic component the polysaccharide pullulan. When applied to the substrate of choice, said formulations provide coatings exhibiting good mechanical strength and flexibility.

Abstract: This invention provides a matrix composition for sustained drug delivery which is comprised of an active agent, a hydrophilic polymer and an enteric polymer. The enteric polymer is impermeable to gastric fluids and aids in retarding drug release in regions of low pH, thus allowing lower levels of hydrophilic polymer to be employed. At the pH range of intestinal fluids, this polymer will dissolve and thereby increase the permeability of the dosage form. This approach is useful in sustaining the release of numerous active agents whose solubility declines as the pH is increased, a characteristic of weakly basic drugs. By responding to changes in physiological pH, these sustained release dosage forms have acceptable performance, in spite of variability in the gastrointestinal transit times of the formulation.

Abstract: The present invention provides sustained release tablets in unit dosage form comprising an active agent which has low aqueous solubility.