Porous micro-cellular drug releasing foams as new implant material in post-surgical chemotherapy
Multi-scale and/or multi-disciplinary approach to process-product innovation
Controlled Release of the Active Ingredient: Mechanisms, Devices & Analysis (T3-2)
Keywords: paclitaxel, supercritical CO2, drug delivery, foam.
Polymeric foams have many potential applications in tissue engineering and drug delivery systems. In this study, paclitaxel, a promising chemotherapeutic agent, was encapsulated in Poly DL lactic-co-glycolic acid (PLGA) foams for controlled delivery in the surgical treatment of carcinomas as a potentially new type of surgical implant material. Using supercritical CO2 as a foaming agent, the use of organic solvent may be minimized or even eliminated in the production of PLGA foams. Various parameters influencing the porous structure of PLGA foams including saturation pressure, temperature, time and the rate of venting were investigated in this study. For encapsulation of paclitaxel, a two-stage fabrication process was used. Firstly, paclitaxel loaded microparticles were fabricated using conventional spray drying. Next, the microparticles were foamed to obtain the solid polymeric foams. Both open cell and closed cell pores were achieved in this study by careful selection of the copolymer composition of PLGA used. Molecular dispersion of paclitaxel in PLGA polymer matrix was achieved in the foamed samples. The foams obtained have good mechanical strength which makes it possible to be used as post-surgical implant similar to Gliadel® wafers. The pore size and size distribution, thermal properties and in vitro swelling behavior of the foams were investigated. The higher surface to volume ratio attributed to the three-dimensional micro-cellular porous structure of the foam allows faster release of the hydrophobic drug, paclitaxel. The in vitro release profile of paclitaxel from the foams show sustained release for more then 5 weeks with a close to linear release profile. As supercritical carbon dioxide has excellent miscibility with many organic solvents, the residual organic solvent content of the samples obtained in this study showed very low levels of residual dichloromethane which was used during the spray drying step.
Presented Tuesday 18, 11:20 to 11:40, in session Controlled Release of the Active Ingredient: Mechanisms, Devices & Analysis (T3-2).
