title: Modulating protein release profiles by incorporating hyaluronic acid into PLGA microparticles Via a spray dryer equipped with a 3-fluid nozzle.
abstract: OBJECTIVE
  The purpose of this study was to modulate the release profiles of the model protein drug from spray dried poly(DL-lactic-co-glycolic acid) (PLGA) microparticles by incorporating hyaluronic acid (HA) in the formulation.
  
  
  METHODS
  Bovine serum albumin (BSA)-loaded PLGA microparticles with or without HA were prepared using a spray dryer equipped with a 3-fluid nozzle. The effects of HA on the surface tension and the rheological behavior of the inner feed solution were investigated. The physicochemical properties of the resulting microparticles were characterized using scanning electron microscopy (SEM), laser diffraction (LD), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). Circular dischoism (CD) was used to characterize conformational integrity of BSA released from the microparticles.
  
  
  RESULTS
  Spherical microparticles with D50 of 5-10 μm were obtained. Addition of HA in inner feed solutions increased the feed viscosity, but with no influence on the surface tension. All inner feed solutions showed non-Newtonian shear thinning behavior and the rheological properties were not time dependent. The CLSM and XPS analyses suggested a core-shell like structure of the microparticles when HA was incorporated. The release profiles of BSA were extended and the initial burst releases were suppressed with an increase in HA in the microparticle formulations. In addition, HA seemed to protect BSA from degradation upon the spray-drying process.
  
  
  CONCLUSIONS
  The present work demonstrates the potential of HA to modulate protein release profile from PLGA microparticle formulations produced via spray drying using 3-fluid nozzle.
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen Ø, Denmark.
authors.forename: Feng
authors.initials: F
authors.lastname: Wan
authors.forename: Morten Jonas
authors.initials: MJ
authors.lastname: Maltesen
authors.forename: Sune Klint
authors.initials: SK
authors.lastname: Andersen
authors.forename: Simon
authors.initials: S
authors.lastname: Bjerregaard
authors.forename: Stefania G
authors.initials: SG
authors.lastname: Baldursdottir
authors.forename: Camilla
authors.initials: C
authors.lastname: Foged
authors.forename: Jukka
authors.initials: J
authors.lastname: Rantanen
authors.forename: Mingshi
authors.initials: M
authors.lastname: Yang
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D004337:Drug Carriers / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods*; D006820:Hyaluronic Acid / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011506:Proteins / Q000737:chemistry*; D012212:Rheology; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013500:Surface Tension
chemical_list: D004337:Drug Carriers; D011506:Proteins; D012996:Solutions; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid; D006820:Hyaluronic Acid