Preparation of polymeric particles in CO(2) medium using non-toxic solvents: formulation and comparisons with a phase separation method.

The aim of this work was to elaborate formulation strategies to encapsulate a protein into biodegradable polymeric particles for sustained release purpose. In this paper, two encapsulation methods will be presented, one dealing with a phase separation phenomenon while the other involving an emulsification/extraction process in CO(2) medium. In those methods, only non-volatile injectable solvents such as glycofurol or isosorbide dimethyl ether were used to dissolve the polymer. Moreover, experimental designs were built up to help us to go further in the understanding of the processes and to better predict output responses in design space. Spherical particles were successfully generated with a satisfactory encapsulation yield. Further characterization steps such as in vitro, in vivo releases will be carried out to validate the interest of our encapsulation methods in the development of drug delivery systems.