Controlled release of 1-β-D-arabinofuranosylcytosine (ara-C) from hydrophilic gelatin microspheres: in vitro studies

The preparation and characterization of gelatin microspheres containing the antitumor drug 1-β-D-arabinofuranosylcytosine (ara-C) and its release kinetic from microspheres are reported. Spherical gelatin microspheres, showing high encapsulation efficiency (58 %) and an average diameter of 18 μm were obtained by a coacervation method. In vitro release experiments demonstrated that ara-C is released from gelatin microspheres in a controlled and reproducible fashion. The biological effect of ara-C released from gelatin microspheres was determined on "in vitro" cultured tumor cell lines, showing that after encapsulation ara-C still retains differentiating and antiproliferative activities comparable with those exhibited by the free drug. Taken together, the results obtained suggest that gelatin based microspheres offer excellent potential as carriers for the controlled release of ara-C after in vivo administration.