Polymeric micelle particle comprising anionic drugs and method of preparing the same

A polymeric micelle particle, comprising:

• an anionic drug as an active ingredient;
• a lipid comprising a cationic lipid;
• and
• an amphiphilic block copolymer,
• wherein the anionic drug forms a complex with the cationic lipid by electrostatic interactions, and the complex of the anionic drug and the cationic lipid is entrapped in the core-shell type polymeric micelle structure of the amphiphilic block copolymer which is an A-B type di-block copolymer comprising a hydrophilic A block forming the shell and a hydrophobic B block forming the core,
• wherein the hydrophilic A block is one or more selected from the group consisting of polyalkyleneglycol, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, and a derivative thereof, and the hydrophobic B block is one or more selected from the group consisting of polyester, polyanhydride, polyamino acid, polyorthoester, and polyphosphazine, and
• wherein the particle is free from a polyethyleneglycol (PEG)-lipid conjugate, and a polyamide (ATTA)-lipid conjugate,
• wherein the hydrophobic B block has a number average molecular weight of 1,000 to 50,000 Dalton,
• wherein a weight ratio of (a) the complex of the anionic drug and the cationic lipid to (b) the amphiphilic block copolymer ((a)/(b)×100) is 0.01 to 50 wt %.