Microencapsulation of peptides and proteins.

Microcapsules were prepared by using a double-emulsion technique. A new production method called 'induced phase separation method' was applied to encapsulate peptides and proteins. To find the optimal adjuvants a matrix was set up combining the appropriate organic solvents and the suitable surfactants. The polymer was chosen with regard to the required release period. The aqueous drug solution was intensively mixed with the organic polymer solution. An aqueous surfactant solution was slowly added to the O/W emulsion. The obtained W/O/W emulsion is stirred under partial vacuum conditions until the organic solvent was removed. After removing the solvent from the W/O/W emulsion the microcapsules were washed and lyophilized. The morphology of the microparticles (spheres, sponges, capsules, surplus polymer) was checked by microscopy, particle size distributions were measured by laser diffraction.