title: In vitro characterization of polyorthoester microparticles containing bupivacaine.
abstract: Laboratory-scale spray-congealing equipment was utilized to fabricate injectable microparticles consisting of polyorthoester and bupivacaine. Operating conditions for the spray-congealing process were optimized to produce microparticles with the desired shape and particle size to yield acceptable syringeability and injectability. Characterizations were performed to determine the chemico-physical properties of polyorthoester before and after microparticle fabrication. Microparticles with different drug loadings and comparable particle sizes were produced, and their in vitro drug-release profiles were determined. The in vitro drug release of microparticles with a high drug loading was markedly faster than those with a low drug loading. This is partially attributed to a more significant initial burst-drug release of the microparticles with a high drug loading. The microparticles have demonstrated the potential to be used for long-acting postsurgery pain management by local injection.
authors.affiliation: Advanced Drug Delivery, Hospital Products Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA. dengjs@hpd.abbott.com
authors.forename: Jone-Shin
authors.initials: JS
authors.lastname: Deng
authors.forename: Luk
authors.initials: L
authors.lastname: Li
authors.forename: Youqin
authors.initials: Y
authors.lastname: Tian
authors.forename: Eric
authors.initials: E
authors.lastname: Ginsburg
authors.forename: Matthew
authors.initials: M
authors.lastname: Widman
authors.forename: Alecia
authors.initials: A
authors.lastname: Myers
mesh_terms: D002045:Bupivacaine / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D008863:Microspheres; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*
chemical_list: D011091:Polyesters; D002045:Bupivacaine