The invention is directed to an improved
drug delivery system that includes a
micelle, comprising
polyethylene glycol and a lipid component, and a pharmaceutical agent dispersed in the lipid component. The
delivery system may also include a targeting ligand. The
micelle delivery system of the invention is capable of stabilizing, inter alia, poorly soluble pharmaceutical agents and increasing their delivery
efficacy. Appropriate pharmaceutical agents useful in the
system of the invention include anti-inflammatory agents, agents for
photodynamic therapy, anti-tumor agents, anti-neoplastic agents, anti-metastatic agents, and imaging agents, as well as hydrophobized derivatives thereof. Specifically, the pharmaceutical agent can be
porphyrin,
chlorine-6-trimethyl ester,
tamoxifen,
paclitaxel, 1,3-bis(2-chloroethyl)-1-
nitrosourea,
camptothecin, ellipticine,
rhodamine, dequalinium, diphenylhexatriene,
vitamin K3,
diethylene triamine pentaacetic acid, or a
functional derivative thereof. The micelles in the
system of the invention have low critical micellar concentration and high kinetic stability, which provides great advantages in
biodistribution, for example, accumulation at the site of a tumor.