Patent ID: 8916206

Claim:
A nanoparticle containing a water-soluble, non-peptide, low-molecular weight drug, the nanoparticle obtained by hydrophobicizing a water-soluble, non-peptide, low-molecular weight drug by a metal ion, and reacting the hydrophobicized drug with a poly(lactic acid)-polyethylene glycol block copolymer or a poly(lactic-co-glycolic acid)-polyethylene glycol block copolymer, and a poly(lactic acid) or a poly(lactic-co-glycolic acid) copolymer, wherein the poly(lactic acid)-polyethylene glycol block copolymer or the poly(lactic-co-glycolic acid)-polyethylene glycol block copolymer has a weight average molecular weight in a range of 3,000 to 20,000, and further comprising a basic low molecular weight compound mixed therein.