The effect of a rate controlling membrane on release from polyhema hydrogels

The possibility of laminating a non-permeable, perforated membrane onto a polymer matrix providing zero-order drug release kinetics has been reported. The work we have undertaken involves an assessment of the suitability of poly(2-hydroxyethylmethacrylate) (polyHEMA) as the matrix in such a system. PolyHEMA hydrogels were prepared by the radiation polymerization of HEMA monomer solutions of different initial water contents. Membranes were laminated during the polymerization process. In Vitro release rates of substituted benzoic acids from laminates were determined.