title: Formulation and in-vitro characterization of retinoic acid loaded poly (lactic-co-glycolic acid) microspheres.
abstract: Poly (lactic-co-glycolic acid) (PLGA) microspheres containing all-trans retinoic acid (atRA) were prepared by emulsion/solvent evaporation technique. PLGA (50:50) with inherent viscosities of 0.17 and 0.39 dL g(-1) was used. Polyvinyl alcohol (PVA) or PVA and sodium oleate (SO) combinations (4:1) were used to stabilize the emulsions. The effect of polymer viscosity, emulsifier type and concentration on the in vitro release of atRA from the microspheres was investigated. The stability of the microparticles was also tested at the temperatures of 4, 25 and 40 degrees C. The particle size ranged between 1-2 microm. Microspheres were smooth and spherical in shape, as determined by scanning electron microscope (SEM) photographs. The yield of microspheres ranged from 50-75% and the encapsulation efficiency was determined between 45-75%. In vitro release studies showed that atRA release from microspheres lasted for 11 days.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Cirpanli
authors.forename: Nurşen
authors.initials: N
authors.lastname: Unlü
authors.forename: Sema
authors.initials: S
authors.lastname: Caliş
authors.forename: A Atilla
authors.initials: AA
authors.lastname: Hincal
mesh_terms: D000970:Antineoplastic Agents; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D045703:Emulsifying Agents / Q000494:pharmacology; D019344:Lactic Acid; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D011142:Polyvinyl Alcohol; D013499:Surface Properties; D013696:Temperature; D014212:Tretinoin; D014783:Viscosity
chemical_list: D000970:Antineoplastic Agents; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D045703:Emulsifying Agents; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D014212:Tretinoin; D011142:Polyvinyl Alcohol