Polymeric micelle as multifunctional pharmaceutical carriers.

A number of formulations have been developed and reported in literature as a carrier for drug, gene, and diagnostic agents. Amphiphilic block copolymers have achieved increasing attention due to their high stability both in vitro and in vivo and their good biocompatibility. In comparison to other long-circulating nanocarriers, micelles possess a number of advantages such as tissue penetrability, reduced toxicity, and controlled drug release. The characteristic features of micelle as carriers, such as particle size, shape, drug loading, cellular internalization, stability, and release kinetics of drugs can be improved by altering the physicochemical properties of the constituent block copolymers and method of preparation. Polymeric micelles formed from amphiphilic blocks have been successfully used for delivery of drugs that lack water solubility. Chelation or incorporation of a diagnostic agent in ligand conjugated micelle may help in tracing in vivo biodistribution. We review a number of research articles demonstrating that micelle formulations can be used efficiently in clinical situations by taking care of the toxicity of surfactants, and the interaction between polymer and drug, to prepare a formulation carrying a more therapeutic agent with a minimum amount of polymer.