The present invention provides a particulate pharmaceutical composition which has improved drug encapsulation stability and is suitable for a drug delivery system. The particulate pharmaceutical composition 1 contains: a plurality of block copolymer unit 2 arranged radially, each of which has a hydrophobic polymer-chain segment 2b, which is arranged radially inside, and a hydrophilic polymer-chain segment 2a, which is arranged radially outside; a drug 4, which includes a biomacromolecule; and a charged lipid 3, which has an electrical charge opposite to that of the drug 4; wherein the charged lipid 3 is being attracted to the hydrophobic polymer-chain segment 2b, and the drug 3 is positioned radially inside the hydrophobic polymer-chain segment 2b. The pharmaceutical composition 1 can effectively prevent the drug 4 from disengaging from the particle.