Production of Albumin Microspheres for Drug Release by Supercritical Assisted Atomization

Microparticulate carriers are widely employed as drug controlled release system. In this work, the Supercritical Assisted Atomization (SAA) technique was used to produce microspheres of Bovine Serum Albumin (BSA), selected as carrier and gentamicin sulphate (GS) as a model drug. The processability of BSA and GS by SAA was studied using water as solvent and microspheres were successfully produced. A modification of the protein secondary structure of BSA, that induced a partial hydrophobic behaviour in water, was observed. This fact is not a disadvantage, since it can prolong the stability of BSA microspheres. Composite microparticles of BSA and GS were then produced. Microspheres with a spherical shape and with a mean particle size of 1 μm were obtained. The controlled release properties of the BSA-loaded microspheres took advantage from the protein structural changes since a longer GS release was observed.