Supercritical assisted injection in a liquid antisolvent for PLGA and PLA microparticle production

Biodegradable and biocompatible polymers PLA (poly lactic acid) and PLGA (poly lactic-co-glycolic acid) have been processed using supercritical assisted injection in a liquid antisolvent (SAILA), to evaluate the possibility to produce microparticles of controlled size and distribution. SAILA experiments were performed varying the process parameters, studying the influence of temperature, gas to liquid ratio (GLR) and polymer concentration on particle size distribution. Spherical, smooth and not coalescing particles were obtained at all process conditions; sub-microparticles (0.46 ± 0.17. μm) and microparticles (2.1 ± 0.84. μm) of PLA and PLGA have been produced with a fairly good control of particle size distribution.Preliminary encapsulation tests have also been performed, using Piroxicam as a model drug. An encapsulation efficiency of about 60% has been obtained. Coprecipitated drug/polymer microparticles allowed a controlled release of the drug for about 5. days.