(624c) Combinatorial And High Throughput Methods For The Design And Characterization Of Libraries For Polymer Blend Phase Behavior

Combinatorial strategies have been developed to study the phase behavior of biodegradable polyanhydrides for drug and protein delivery applications. The polyanhydrides of interest are poly[1,6-bis(p-carboxyphenoxy) hexane] (CPH) and poly[sebacic anhydride] (SA). Both continuous and discrete polymer blend libraries were fabricated by using a combination of solution-based gradient deposition and rapid prototyping. Blend compositions were characterized via a unique high throughput transmission mode FTIR sampling technique and compared against theoretical mass balance predictions. To obtain phase diagrams of CPH/SA, the effect of blend composition and annealing temperature on the miscibility of the blend was studied. This gradient library was observed with optical microscopy in order to determine cloud points. These results were compared with SAXS studies on discrete libraries, which contained previously specified blend compositions and the agreement between the two methods was very good. The CPH/SA system exhibits upper critical solution temperature behavior.