title: Designing multilayered particulate systems for tunable drug release profiles.
abstract: Triple-layered microparticles comprising poly(D,L-lactide-co-glycolide, 50:50) (PLGA), poly(L-lactide) (PLLA) and poly(ethylene-co-vinyl acetate, 40 wt.% vinyl acetate) (EVA) were fabricated using a one-step solvent evaporation technique, with ibuprofen drug localized in the EVA core. The aim of this study was to investigate the drug release profiles of these triple-layered microparticles in comparison to double-layered (PLLA/EVA and PLGA/EVA) (shell/core) and single-layered EVA microparticles. Double- and triple-layered microparticles were shown to eliminate burst release otherwise observed for single-layered microparticles. For triple-layered microparticles, the migration of acidic PGA oligomers from the PLGA shell accelerated the degradation of the PLLA mid-layer and subsequently enhanced drug release in comparison to double-layered PLLA/EVA microparticles. Further studies showed that drug release rates can be altered by changing the layer thicknesses of the triple-layered microparticles, and through specific tailoring of layer thicknesses, a zero-order release can be achieved. This study therefore provides important mechanistic insights into how the distinctive structural attributes of triple-layered microparticles can be tuned to control the drug release profiles.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Wei Li
authors.initials: WL
authors.lastname: Lee
authors.forename: Pattara-orn
authors.initials: PO
authors.lastname: Yu
authors.forename: Meiju
authors.initials: M
authors.lastname: Hong
authors.forename: Effendi
authors.initials: E
authors.lastname: Widjaja
authors.forename: Say Chye Joachim
authors.initials: SC
authors.lastname: Loo
mesh_terms: D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D007052:Ibuprofen / Q000493:pharmacokinetics*; D019344:Lactic Acid; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011145:Polyvinyls; D013059:Spectrum Analysis, Raman
chemical_list: D011091:Polyesters; D011145:Polyvinyls; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C016438:ethylenevinylacetate copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D007052:Ibuprofen