Key words: bioresorbable polymers, polymer microparticles, supercritical carbon dioxide, acoustic excitation
A new approach to control the process of «dry» (without any use of organic solvents) synthesis of bioresorbable polymer microparticles and porous fibers has been proposed and developed. It is based on the combination of treatment in supercritical fluids and intensive acoustic excitation. Low molecular weight (Mw ~ 1000) ε-polycaprolactone and D,L-polylactide microparticles and their agglomerates which can be used as a drug delivery vehicles were produced by spraying of the polymers plasticized in supercritical CO2 through the pulse nozzles. The significant lowering of the initial D,L-polylactide viscosity has been achieved by intensive acoustic agitation in supercritical fluid environment followed by the morphology changes of the final product. No noticeable alterations of both polymer molecular weight and polydispersity (Mw/Mn ratio) after the treatment were detected.