Patent ID: 7659314

Claim:
A method for treating a warm-blooded animal with a drug comprising: (a) mixing the drug with a pH-sensitive mixed polymeric micelle composition comprising (i) poly(L-histidine)-poly (ethylene glycol) block copolymer and poly(L-lactic acid)-poly (ethylene glycol) block copolymer, (ii) poly(L-histidine)-poly (ethylene glycol) block copolymer-folate and poly(L-lactic acid)-poly(ethylene glycol) block copolymer, (iii) poly(L-histidine)-poly (ethylene glycol) block copolymer and poly(L-lactic acid)-poly (ethylene glycol) block copolymer-folate, or (iv) poly(L-histidine)-poly(ethylene glycol) block copolymer-folate and poly(L-lactic acid)-poly(ethylene glycol) block copolymer-folate, to result in a drug-loaded mixed micelle composition; and (b) administering the drug-loaded mixed micelle composition to the animal such that the drug-loaded mixed micelle composition is systemically circulated in the animal, wherein the drug-loaded mixed micelle composition is stable in blood and releases the drug in acidic conditions.