Acta Pharm. 54 (2004) 215-229

Poly(lactide-co-glycolide) microparticles as systems for controlled release of proteins - Preparation and characterization

ALEKSANDRA PORJAZOSKA,¹ KATERINA GORACINOVA², KRISTINA MLADENOVSKA², MARIJA GLAVAS², MAJA SIMONOVSKA², EMILIJA IVANOVSKA JANJEVIC³ and  MAJA CVETKOVSKA^1*

majac@ereb1.mf.ukim.edu.mk; majac@ian.tmf.ukim.edu.mk

¹Institute of Organic Technology, Faculty of Technology and Metallurgy
²Institute of Pharmaceutical Technology, Faculty of Pharmacy
³ Institute of Nuclear Medicine and Pathophysiology, Faculty of Medicine, University "Ss Cyril and Methodius", Skopje, R. Macedonia

Poly(DL-lactide-co-glycolide) (PDLLGA) and poly(L-lactide-co-glycolide) (PLLGA) copolymers were prepared by bulk ring opening polymerization of lactide and glycolide and characterized by GPC, FTIR, ¹H NMR and DSC. Copolymers with different molar masses at a constant lactide/glycolide ratio were used for preparation of bovine serum albumin (BSA)-loaded microparticles by the double emulsion w/o/w method. The influence of the copolymer molar mass and composition on the microparticle morphology, size, yield, degradation rate, BSA-loading efficiency and BSA release profile were studied. For microparticles prepared from PDLLGA copolymers, a biphasic profile for BSA release was found and for those made from PLLGA copolymers the release profile was typically triphasic; both of them were characterized by high initial burst release. Possible reasons for such behavior are discussed.

Keywords: poly(lactide-co-glycolide), microparticles, protein, in vitro release