title: Impact of microparticle formulation approaches on drug burst release: a level A IVIVC.
abstract: OBJECTIVE
  To study the effect of poly(d,l-lactic-co-glycolic acid) (PLGA) microparticles (MPs) preparation techniques on particle physical characterization with special emphasis on burst drug release.
  
  
  METHODS
  A basic drug clozapine was used in combination with acid-terminated PLGA. Two approaches for MP preparation were compared; the in situ forming microparticle (ISM) and the emulsion-solvent evaporation (ESE) methods using an experimental design. The MPs obtained were compared according to their physical characterization, burst release and T80%. An in vivo pharmacokinetic study with in vitro-in vivo correlation (IVIVC) was also performed for the selected formula.
  
  
  RESULTS
  Both methods were able to sustain drug release for three weeks. ISM produced more porous particles and was not effective as ESE for controlling burst release. A good IVIVC (R(2) = 0.9755) was attained when injecting the selected formula into rats.
  
  
  CONCLUSIONS
  MPs prepared with ESE showed a minimum burst release and a level A IVIVC was obtained when administered to rats.
authors: Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University , Cairo , Egypt.
authors: Rania A H
authors: RA
authors: Ishak
authors: Nahed D
authors: ND
authors: Mortada
authors: Noha M
authors: NM
authors: Zaki
authors: Abd El-Hamid A
authors: Ael-H
authors: El-Shamy
authors: Gehanne A S
authors: GA
authors: Awad
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D003024:Clozapine / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D003692:Delayed-Action Preparations; D019344:Lactic Acid / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D011100:Polyglycolic Acid / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats
chemical_list: D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003024:Clozapine
keywords: Burst release; IVIVC; factorial design; in situ forming microparticles; polymer Tg; uncapped PLGA