A pharmaceutical preparation containing magnetic vesicular particles is disclosed, wherein the magnetic vesicular particles each include magnetic microparticles within a lipid membrane, an organic compound having at least two groups selected from the group consisting of a hydroxyl group, a carboxyl group, a carbamoyl group, an amino group, a mercapto group, a sulfo group, a dithio group, a thiocarboxyl group and a dithiocarboxyl group is bonded to the magnetic microparticle, and the magnetic vesicular particles satisfy the following equation: 0.05.ltoreq.R/(r.times.100).ltoreq.1.5 wherein R represents an average grain size of the magnetic vesicular particles and r represents an average particle size of magnetic microparticles included in the magnetic vesicular particles.