Hydroxy-urea bearing albumin microspheres--preparation, characterization and evaluation

Hydroxy-urea bearing albumin microspheres were prepared using the polymer dispersion method. Glycerol was used successfully in place of water as an internal phase of w/o emulsion, to prepare HSA based albumin microspheres. Silicone coated magnetite of nanometeric size was incorporated in the drug bearing microspheres. The process variables which could affect the physical characteristics with respect to in vitro and in vivo performance of the prepared microspheres were studied. The in vitro release of the drug from the microspheres followed a linear relationship when commulative per cent drug release was plotted against square root of time. Microspheres of average size 1-4 microns were studied for in vivo distribution and localization. It was established that 67 per cent of the drug enveloped in magnetic albumin microspheres could be localized in a rat tail target segment, on applying an external magnetic field of strength 8000 Oe. A remarkable stabilization of hydroxy urea in the prepared microspheres was recorded when t10% drug degradation was compared with the albumin microspheres prepared by a conventional emulsion polymerization method using water as an internal phase.