Tuning the release profile of ketoprofen from poly(L-lactic acid) suture using supercritical CO2 impregnation process

Poly(c-lactic acid) (PLLA) fibers were impregnated with the anti-inflammatory drug ketoprofen by supercritical CO2 (scCO(2)) assisted impregnation process, to develop drug-eluting absorbable sutures. This work indicates the possibility to tune not only the drug loading but also the release profile of ketoprofen from PLLA by modifying the impregnation (temperature and pressure) and depressurization (temperature and rate) conditions. Different PLLA sutures that release ketoprofen during 3 days up to 3 months were obtained. The release was shown to be governed by two parameters: the degradation rate of PLLA, that increases with the drug impregnation, and the sutures free volume, that was created due to scCO(2) sorbed and was partially conserved during depressurization. The degradation rate and the tensile strength loss of the suture are accelerated by ketoprofen since it catalyzes PLLA acid hydrolysis.