Copolymerization of D,L‐lactide and glycolide in supercritical carbon dioxide with zinc octoate as catalyst

Abstract The objective of the study is the development of a new technique based on supercritical technology for the production of bioabsorbable polymeric microparticles containing pharmaceutical principles, for their use in the controlled release of medicines. For this purpose, the ring‐opening copolymerization of D,L‐lactide and glycolide in supercritical carbon dioxide, using zinc(II) 2‐ethylhexanoate (ZnOct₂) as catalyst, was studied. The polymer obtained with ZnOct₂ has similar characteristics to that obtained with stannous octoate (SnOct₂), the conventional catalyst used up to now for this kind of polymerization process. Experiments were performed at various reaction times, pressures, and stirring rates. The most outstanding result was found by varying the stirring rate, where particles forming agglomerates seem to be obtained at the greater agitation levels. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008