New macromolecular carriers for drugs. I. Preparation and characterization of poly(oxyethylene‐<i>b</i>‐isoprene‐<i>b</i>‐oxyethylene) block copolymer aggregates

Abstract

Abstract This work describes the formation of discrete micelles (⋍ 0.1 μm) from ABA poly(oxyethylene‐ b ‐isoprene‐ b ‐oxyethylene) block copolymers in water. An efficient labeling of the micelles by polymerization of [ 14 C]‐styrene within the hydrophobic core is also described. These micellar nanoparticles are being considered as promising materials for controlled release and/or site‐specific drug delivery systems. In experimental animals the micelles remained in circulation with a half‐life in excess of 50 h. Our results demonstrate the advantages of using block copolymers for the preparation of “perfect” biocompatible surfaces such as are required for well‐tolerated, long‐circulating particulate drug carriers.