METHYLMETHACRYLATE SULFOPROPYLMETHACRYLATE COPOLYMER NANOPARTICLES FOR DRUG-DELIVERY - PART II - ARECAIDINE PROPARGYL ESTER AND PILOCARPINELOADING AND IN-VITRO RELEASE

Methylmethacrylate (MMA) sulfopropylmethacrylate (SPM) copolymer nanop articles were prepared by free radical polymerization and the loading characteristics of the muscarinic agonists arecaidine propargyl ester (APE) and pilocarpine were investigated. The loading efficiency was ma inly influenced by the concentration of the copolymer carrier system a nd followed Langmuir's adsorption equation. The in vitro drug release was mainly influenced by the composition of the acceptor phase used an d the nanoparticle content of the donor phase. The bound drug was rele ased from the carrier by competitive replacement by other ions from th e binding sites of the particles. By this mechanism the nanoparticle s ystem achieved a prolonged drug release, which was not the result of t he increased viscosity at higher nanoparticle concentrations. (C) 1997 Elsevier Science B.V.