title: Microparticles prepared with poly(hydroxybutyrate-co-hydroxyvalerate) and poly(epsilon-caprolactone) blends to control the release of a drug model.
abstract: The objective of this work was to verify the influence of the poly(epsilon-caprolactone) PCL concentration in poly(hydroxybutyrate-co-hydroxyvalerate) P(HBHV)/PCL microparticles, prepared by an emulsion/solvent evaporation process, on the release behavior of a drug. Differential Scanning Calorimetry analyses demonstrated that the preparation process increased the crystallite heterogeneity for the P(HBHV) in the particles. The drug caused an increase in the glass transition of the P(HBHV) in the microparticles. Dexamethasone acetate-loaded microparticles demonstrated drug sustained releases (up to 250 h), which profiles fit the biexponential model. The release of dexamethasone acetate caused an increase in the surface area of the microparticles. The kinetic constants of the sustained phase increased with the augmentation of the PCL content in the blend. The drug release mechanism was dependent on the presence of PCL in the microparticles. A Fickian release was determined for the microparticles prepared exclusively with P(HBHV), while non-Fickian release behaviors were found for the P(HBHV)/PCL microparticles.
authors: Faculdade de Farmácia, Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors: Maria I Z
authors: MI
authors: Lionzo
authors: Maria I
authors: MI
authors: Ré
authors: Silvia S
authors: SS
authors: Guterres
authors: Adriana R
authors: AR
authors: Pohlmann
mesh_terms: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D006885:Hydroxybutyrates; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D010316:Particle Size; D011091:Polyesters; D013053:Spectrophotometry; D014631:Valerates
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D006885:Hydroxybutyrates; D011091:Polyesters; D014631:Valerates; C016240:polycaprolactone; C073314:poly(3-hydroxyvalerate)