title: Interfacial Fast Release Layer in Monodisperse Poly (lactic-co-glycolic acid) Microspheres Accelerates the Drug Release.
abstract: Understanding microstructural evolutions of drug delivery devices during drug release process is essential for revealing the drug release mechanisms and controlling the drug release profiles. In this study, monodisperse poly (lactic-co-glycolic acid) microspheres in different diameters were fabricated by microfluidics in order to find out the relationships between the microstructural evolutions and the drug release profiles. It was found that poly (lactic-co-glycolic acid) microspheres underwent significant size expansion which took place from the periphery to the center, resulting in the formation of interfacial fast release layers. At the same time, inner pores were created and the diffusion rate was increased so that the early stage drug release was accelerated. Due to the different expansion rates, small poly (lactic-co-glycolic acid) microspheres tendered to follow homogeneous drug release while large poly (lactic-co-glycolic acid) microspheres tendered to follow heterogeneous drug release. This study suggests that the size expansion and the occurrence of interfacial fast release layer were important mechanisms for early stage drug release of poly (lactic-co-glycolic acid) microspheres.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhao
authors.forename: Kelvin W K
authors.initials: KW
authors.lastname: Yeung
authors.affiliation: Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, HKU, HK, China. mikektto@hku.hk.
authors.forename: Michael K T
authors.initials: MK
authors.lastname: To
mesh_terms: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004339:Drug Compounding; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D012293:Rifampin / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012293:Rifampin