title: Preparation of sustained release microparticles with improved initial release property.
abstract: The objective of this study was to investigate the potential of various formulation strategies to achieve sustained release of the peptide, from injectable poly(D,L-lactide-co-glycolide) (PLGA) and d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) microparticles. The microparticles were prepared by a solvent evaporation method. Peptide loaded PLGA microparticles exhibited a pronounced initial burst release (22.3% in 1 day) and lag phase in phosphate buffer of pH 7.0. In contrast, blending of 5.0% TPGS (8.6% release in 1 day) or 10.0% TPGS (5.5% release in 1 day) in PLGA microparticles reduced initial burst release and the lag-phase time. Incorporation of TPGS in PLGA microparticles further increased drug release, attributable to improved drug encapsulation, increased particle size, and exempt of pores. PLGA+ 10.0% TPGS composite microparticles exhibited the most desirable drug release among all the formulations tested, and demonstrated triphasic release after minimal initial burst.
authors.affiliation: College of Pharmacy, Chungnam National University, Daejeon, 305-764, Korea.
authors.forename: Goo-Young
authors.initials: GY
authors.lastname: Jung
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Na
authors.forename: Mork-Soon
authors.initials: MS
authors.lastname: Park
authors.forename: Chang-Sik
authors.initials: CS
authors.lastname: Park
authors.forename: Pyung-Keun
authors.initials: PK
authors.lastname: Myung
mesh_terms: D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004339:Drug Compounding; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry*; D015282:Octreotide / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012995:Solubility; D013499:Surface Properties; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D014810:Vitamin E; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols; C014225:tocophersolan; D015282:Octreotide