Influence of physico-chemical parameters on the release of hydrocortisone acetate from albumin microspheres

We describe the preparation of bovine serum albumin microparticles, loaded with hydrocortisone acetate by mixing different drug dispersing phases with the protein aqueous solution before thermal crosslinking. The influence of the drug dispersing phase is analysed in terms of the physico-chemical properties correlated to release. The release of the drug from the microparticles is initially Fickian or Anomalous, subsequently approaches zero order and finally is exponentially correlated to time. The drug dispersing phases able to induce hydrophilic modifications on the polymeric structure, increase the duration of the zero order release owing to modifications on the diffusion coefficient and solubility of the drug in the matrix.