Drug release from PLGA microspheres attached to solids using supercritical CO₂

J Biomater Appl. 2011 Jan;25(5):401-12. doi: 10.1177/0885328209354365. Epub 2009 Dec 30.

Abstract

Functionalization of a porous orthopedic implant with dexamethasone, a widely used anti-inflammatory drug, encapsulated within a biodegradable polymer for controlled release could help reduce or eliminate the inflammation response by the local tissue. In this research, we investigated the possibility of using supercritical carbon dioxide (CO₂) for attaching dexamethasone-loaded PLGA (polylactic-co-glycolic acid) microspheres to porous CoCrMo alloy for continuous delivery of dexamethasone. Supercritical CO₂ has been shown to be effective for attachment of PLGA microspheres to glass plates and porous CoCrMo alloy. Attached microspheres showed similar dexamethasone release profiles but different magnitude of burst release. Microspheres attached to the porous alloy samples using supercritical CO₂ at 10 bar and 40 °C for 30 min showed a release profile similar to that of the nonattached microspheres. The microsphere morphology and the release profiles of microspheres attached to the glass plates and to the porous alloy samples suggest that dexamethasone burst release is enhanced by PLGA swelling at higher CO₂ pressures and better dispersion of microspheres. This study shows that microspheres can be incorporated into porous solids using supercritical CO₂, allowing for a wide variety of drug-biodegradable polymer formulations prepared using the proven emulsion/solvent evaporation method to be tested.

MeSH terms

  • Biocompatible Materials
  • Carbon Dioxide
  • Chromium Alloys
  • Coated Materials, Biocompatible
  • Dexamethasone / administration & dosage*
  • Dexamethasone / pharmacokinetics
  • Drug Delivery Systems*
  • Glass
  • Humans
  • In Vitro Techniques
  • Lactic Acid*
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Microspheres
  • Polyglycolic Acid*
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Prostheses and Implants
  • Surface Properties

Substances

  • Biocompatible Materials
  • Chromium Alloys
  • Coated Materials, Biocompatible
  • Carbon Dioxide
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • Dexamethasone