title: Formulation and characterization of ethylcellulose microparticles containing .L-alanyl- L-glutamine peptide.
abstract: BACKGROUND
  The L-alanyl-L-glutamine peptide (AGP) has been effective to promote acute glycemia recovery during long-term insulin-induced hypoglycemia (IIH), and the oral administration of AGP is suggested to prevent prolonged hypoglycemia, such as nocturnal hypoglycemia.
  
  
  OBJECTIVE
  Considering the ability of AGP on glycemia recovery and AGP's fast metabolism, the aim of current study was to obtain and characterize ethylcellulose microparticles to deliver the drug for a prolonged time.
  
  
  METHODS
  Microparticles were prepared by simple and double emulsification/hardening method and characterized by scanning electron microscopy, thermogravimetry (TG), differential scanning calorimetry (DSC), Fourier transform infra-red (FTIR) and FT-Raman spectroscopy and in vitro release.
  
  
  CONCLUSIONS
  Spherical structures with a mean diameter between 9.30 µm and 13.19 µm were formed. TG analysis showed that the thermal stability of AGP was even more increased by encapsulation with ethylcellulose. In addition, TG, DSC, FTIR and FT-Raman analyses proved that AGP was encapsulated in a molecular way. Higher values of encapsulation efficiency were observed for the microparticles prepared by double emulsification (57.83-83.67%) than for those prepared by simple emulsification (18.37%). However, the last ones could release the peptide in a quicker and more extensive manner than those prepared by double emulsification.
  
  
  CONCLUSIONS
  For the first time, microparticles containing AGP were developed and exhibited prolonged in vitro release as well as protection to the drug, and it could be considered as a dosage form for patients who suffer from insulin-induced hypoglycemia and/or nocturnal hypoglycemia.
authors.affiliation: Department of Pharmacy .
authors.forename: Mônica
authors.initials: M
authors.lastname: Villa Nova
authors.forename: Marise de Cássia Pires
authors.initials: Mde C
authors.lastname: Gonçalves
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Nogueira
authors.forename: Leandro da Silva
authors.initials: Lda S
authors.lastname: Herculano
authors.forename: Antônio Neto
authors.initials: AN
authors.lastname: Medina
authors.forename: Roberto Barbosa
authors.initials: RB
authors.lastname: Bazotte
authors.forename: Marcos Luciano
authors.initials: ML
authors.lastname: Bruschi
mesh_terms: D000284:Administration, Oral; D002152:Calorimetry, Differential Scanning; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations; D004151:Dipeptides / Q000008:administration & dosage* / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods; D065546:Drug Liberation; D004355:Drug Stability; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D013818:Thermogravimetry
chemical_list: D003692:Delayed-Action Preparations; D004151:Dipeptides; D004337:Drug Carriers; C013517:ethyl cellulose; D002482:Cellulose; C054122:alanylglutamine
keywords: Drug delivery system; ethylcellulose, l-alanyl-l-glutamine; nocturnal hypoglycemia; simple and double emulsification/hardening method