Inclusion of Pharmaceutical Compounds in Polymeric Membranes Produced by Supercritical Processing

摘要

Loaded polymeric membranes and aerogels have been prepared using, respectively, a supercritical fluid based phase inversion process in which COi acts as the nonsolvent and a supercritical drying process. We prepared polymeric membranes and gels of PVDF-HFP loaded with a model drug, amoxicillin, using two different processes. To produce loaded membranes we prepared a dispersion of the drug in the organic solution formed by polymer and solvent; instead, gels have been prepared adding ethanol to the casting solution and cooling it at -20°C for 30 min. Loaded membranes and aerogels, produced at various drug loadings, were characterized by SEM, to study the morphology and cells size, by DSC to analyze drug-polymer interactions in the membrane and by microanalysis (EDX) to examine the drug distribution in the polymeric matrix. Moreover, drug release rate analysis were performed to observe the different release behaviors. The results are very different depending on supercritical process used: phase inversion or gel drying. In the first case we obtained cellular structure with non homogeneous drug distribution and consequently a fast drug release; when we prepare aerogels, instead, the structure results more homogeneous, with no dmg concentration gradient along the section.