Supercritical Assisted Atomization (SAA) is proposed for the production of nanostructured microparticles of Bovine Serum Albumin (BSA) loaded with lincomycin hydrochloride (lincoHCl). The process is used to coprecipitate BSA and lincoHCl, producing thermal denaturated BSA microparticles, entrapping the drug in the protein matrix. Several lincoHCl/BSA ratios in water solutions were processed, to produce protein microspheres with different size and drug content. SAA precipitation temperature was set as 100 degrees C to obtain BSA coagulation and efficient entrapping of lincoHCI. Spherical microparticles showed no coalescence and were produced in all cases studied, with a mean particle size in the range 1-2 mu m and loading efficiencies between 87 and 90%. The microspheres produced by SAA showed a controlled release of the drug over about 6 days. (C) 2016 Elsevier B.V. All rights reserved.