title: [In vitro drug release profiles and mucoadhesive property of bioadhesive microspheres of metronidazole].
abstract: OBJECTIVE
  To prepare bioadhesive microspheres of metronidazole (Metro) with prolonging resident time in the stomach and sustaining drug release.
  
  
  METHODS
  The microspheres were prepared by a drying-in-liquid method. The appearance, particle size and drug release in vitro were examined. The factors influencing bioadhesive property and drug release, such as ethyl cellulose (EC)/carbopol 934P (CP) ratio, particle size and Metro content were investigated.
  
  
  RESULTS
  The average diameter of the Metro-EC-CP microspheres was 559.9 microns. The release profiles of metronidazole were shown to fit to first-order equations well. With the increase of CP content in the Metro-EC-CP microspheres, the microspheres showed better mucoadhesion and faster drug release. The drug release rate decreased with the increase of particle size and the decrease of Metro content.
  
  
  CONCLUSIONS
  The Metro-EC-CP microspheres have a sound mucoadhsive property and sustained drug release when the ratio of EC and CP was 17:3 and Metro content was 25%. The drug release was shown to last for 8 h in 0.1 mol.L-1 hydrochloric acid.
authors.affiliation: Department of Pharmaceutics, Fudan University, Shanghai 200032, China.
authors.forename: Jing-lin
authors.initials: JL
authors.lastname: Huang
authors.forename: Jin-fang
authors.initials: JF
authors.lastname: Lu
mesh_terms: D000179:Acrylates; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000494:pharmacology; D002448:Cell Adhesion; D003692:Delayed-Action Preparations; D005260:Female; D005466:Fluorocarbons / Q000737:chemistry; D005753:Gastric Mucosa / Q000502:physiology; D008795:Metronidazole / Q000008:administration & dosage* / Q000494:pharmacology; D008863:Microspheres; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000179:Acrylates; D000890:Anti-Infective Agents; D003692:Delayed-Action Preparations; D005466:Fluorocarbons; D008795:Metronidazole; C012964:ethylcellulose perfluorobutyrate; C453622:carbopol 934P