The comparison of theophylline permeabilities from hydrophilic polyhydroxyethylmethacrylate and hydrophobic polyurethane, polyvinylchloride membranes

Abstract

In this study, the diffusion characteristics of theophylline through polyurethane (PU), polyvinylchloride (PVC) and polyhydroxyethylmethacrylate (PHEMA) membranes were investigated for their usage as oral controlled-release reservoir systems. PU and PVC membranes were prepared by the solvent-casting method and PHEMA membrane was prepared by bulk polymerization of 2-hydroxyethylmethacrylate in different thicknesses. Diffusion measurements were performed in simulated gastric fluid and simulated intestinal fluid during 10 h at 37°C using a diffusion cell. Permeability coefficients calculated from diffusion experiments were found to be approximately 10 times higher in PHEMA than PU and PVC membranes.