Drug Loading of Sutures by Supercritical CO2 Impregnation: Effect of Polymer/Drug Interactions and Thermal Transitions

This paper aims at exploring the scCO2 impregnation of three commonly implanted polymer sutures made of poly-l-lactide (PLLA), poly(ethylene terephthalate) (PET) and polypropylene (PP) with two anti-inflammatory drugs namely ketoprofen and aspirin. For all the investigated polymer/drug systems, the drug loading increases with temperature and pressure. It appears that two main criteria must be fulfilled by the polymer to achieve high drug loading: (i) a good affinity between the polymer and the drug and (ii) a high chain mobility to favor the diffusion of the drug into the matrix. As the investigated PLLA fulfills these two requirements, drug loading up to 32.5% with ketoprofen and 8.1% with aspirin has been achieved.