AbstractReferences1. Silvestri D , Gagliardi M , Cristallini C , Barbani N , Giusti P. Different composition poly(methyl methacrylate-co-butyl methacrylate) copolymers through seeded semi-batch emulsion polymerization. Polym Bull 2009; 63: 423–39.2. Ritger PL , Peppas NA. A simple equation for description of solute release I. Fickian and non-fickian release from non-swellable devices in the form of slabs, spheres, cylinders or discs. J Control Release 1987; 5: 23–36.