Hierarchical Structure in Polymer-Based Drug Delivery Systems as Probed by Calorimetric Measurements

作者：Valot Pascale; Sintes Zydowicz Nathalie; Nedelec Jean Marie; Baba Mohamed^*

来源：Journal of Polymer Science Part B: Polymer Physics , 2010, 48(18): 1939-1945.

DOI：10.1002/polb.22068

• differential scanning calorimetry (DSC)
• drug delivery system
• emulsion polymerization
• hierarchical structure
• microencapsulation
• phase transition
• polymer microcapsule
• soft matter
• thermoporosimetry

Thermoporosimetry (TPM), a differential scanning calorimetry technique that relies on the shift of transition temperatures caused by the confinement of liquids, was applied to elucidate the complex morphology of drug-loaded polymeric microcapsules prepared by the emulsion solvent evaporation method. For the very first time, TPM has been applied simultaneously with two liquids as structural probes. It was found that Miglyol, which dissolves the selected drug (Ibuprofen), is confined inside vesicles having a mean radius of 26.3 nm, whereas water, which is the continuous phase, is trapped inside a swollen polymeric network of Eudragit with an average mesh radius of 1.7 nm. A proposed hierarchical structure is given, which predicts that Eudragit microcapsules are formed from a collection of inert oil vesicles partitioned by polymeric Eudragit membranes swollen by water.

• 出版日期2010-9-15