
doi: 10.1002/jbm.10209
pmid: 12209902
AbstractBiodegradable polymeric devices for drug delivery and tissue engineering are often fabricated with the use of organic solvents and may still contain significant amounts of solvent (> 1 wt%) even after aggressive vacuum drying. This excess solvent can interfere with tissue response and the mechanical properties of the devices. The aim of this article is to demonstrate that liquid CO2 extraction can be used to reduce residual solvent in dense poly(L‐lactide‐co‐glycolide) devices to 50 ppm relatively quickly and with minimal changes in architecture under some conditions. Two liquid CO2 extraction systems were developed to examine the removal of residual solvents from bar‐shaped PLGA devices: (1) a low‐pressure (1400 psi) batch system, and (2) a high‐pressure (5000 psi) continuous‐flow system. Eight hours of extraction in the high‐pressure system reduced residual chloroform in 3 mm thick bars below the 50‐ppm target. A simple Fickian diffusion model was fit to the extraction results. Diffusion coefficients ranged from 1.10×10−6 cm2/s to 2.64×10−6 cm2/s. The model predicts that ∼1 h is needed to dry 1‐mm bars to chloroform levels below 50 ppm, and 7 h are needed for 3 mm thick bars. The micro‐ and macroarchitectures of porous PLGA scaffolds created by particulate leaching were not significantly altered by CO2 drying if the salt used to make the pores was not removed before drying. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 567–576, 2002
Drug Carriers, Polymers, Biocompatible Materials, Carbon Dioxide, Polylactic Acid-Polyglycolic Acid Copolymer, Absorbable Implants, Microscopy, Electron, Scanning, Solvents, Chloroform, Lactic Acid, Mathematics, Polyglycolic Acid
Drug Carriers, Polymers, Biocompatible Materials, Carbon Dioxide, Polylactic Acid-Polyglycolic Acid Copolymer, Absorbable Implants, Microscopy, Electron, Scanning, Solvents, Chloroform, Lactic Acid, Mathematics, Polyglycolic Acid
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