Effect of Surfactant Agents on the in Vitro Release of Insulin from DL-PLA Microspheres

Abstract

This paper describes the effect of surfactants on the in vitro release profile of bovine insulin from DL-polyacetic acid (DL-PLA) microspheres prepared by the double-emulsion technique. The surfactants, Tween®-80 and Span®-60, were included in the water and oil phases, respectively, of the first emulsion. The presence of these agents affected the burst effect but not the subsequent release phase. The latter is more controllable by PLA molecular weight selection, with slower release being achieved as the molecular weight increases.