Controlled macromolecule release from poly(phosphazene) matrices

Abstract Hydrolytically unstable poly(phosphazene) PPHOS matrices with 50% ethyl glycinato/50% p -methylphenoxy substitution were investigated as vehicles for the controlled release of macromolecules. Specifically, the effects of matrix pH environment and macromolecule loading were studied. 14 C-labeled inulin was incorporated into matrices by a solvent casting technique at 1, 10 and 40% loadings (w/w). Degradation and release studies were performed at 37°C at pH 2.0, 7.4 and 10.0. The PPHOS polymer degraded relatively slowly in neutral and basic solutions (pH 7.0 and pH 10.0). In contrast, significantly ( p