Magnetic microspheres: synthesis of a novel parenteral drug carrier.

The synthesis and characterization of a novel parenteral drug carrier capable of area specific localization by magnetic means are described. The carrier consists of human serum albumin microspheres, average of 1 micrometer in diameter, in which a magnetizable material (magnetite) and a prototype drug (doxorubicin) are entrapped. Stabilization of the microsphere matrix by formaldehyde, 2,3-butanedione, and heat conferred equal stability to the matrix but differentially affected the in vitro drug release rate. Release doxorubicin was chemically identical to the starting material.