title: Preparation oral levofloxacin colon-specific microspheres delivery: in vitro and in vivo studies.
abstract: The aim of this study was to prepare levofloxacin-loaded chitosan microspheres and to evaluate their in vitro and in vivo characteristics. Glutaraldehyde-crosslinked microspheres were prepared using a spray-drying method, and characterized in terms of the morphological examination, particle size distribution, entrapment efficiency, drug loading and in vitro release. Pharmacokinetics and colon biodistribution studies were used to evaluate that microspheres have more advantage than the conventional formulations. The surface morphology of the freeze-dried microspheres were smooth, discrete with a regular spherical to near-spherical shape. Size of the microspheres after freeze-drying was 4.96 ± 0.76 μm and well-distributed. The zeta potential of microspheres was -29.3 ± 2.1 mV. An average drug loading of 9.3 ± 0.4% and encapsulation efficiency of 81.1 ± 4.7% of levofloxacin microspheres were obtained with the optimized preparation parameters. The cumulative release rate of levofloxacin microspheres was followed by a sustained release and fitted for classic Higuchi kinetic model. In vivo studies showed that chitosan microspheres are thought to have the potential to maintain levofloxacin concentration within target ranges for a long time, decreasing side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. It also does not cause any harmful or toxic effect in colon and rectum as evaluated by histopathologic studies.
authors.affiliation: a Department of Gastroenterology , Putuo Hospital, Shanghai University of Traditional Chinese Medicine , Shanghai , China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.affiliation: a Department of Gastroenterology , Putuo Hospital, Shanghai University of Traditional Chinese Medicine , Shanghai , China.
authors.forename: Yicun
authors.initials: Y
authors.lastname: Ding
authors.affiliation: a Department of Gastroenterology , Putuo Hospital, Shanghai University of Traditional Chinese Medicine , Shanghai , China.
authors.forename: Mingli
authors.initials: M
authors.lastname: Feng
authors.affiliation: a Department of Gastroenterology , Putuo Hospital, Shanghai University of Traditional Chinese Medicine , Shanghai , China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Cao
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002626:Chemistry, Pharmaceutical / Q000379:methods; D048271:Chitosan / Q000737:chemistry; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods; D005612:Freeze Drying / Q000379:methods; D005976:Glutaral / Q000737:chemistry; D064704:Levofloxacin / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D008863:Microspheres; D010316:Particle Size; D051381:Rats; D014018:Tissue Distribution
chemical_list: D064704:Levofloxacin; D048271:Chitosan; D005976:Glutaral
keywords: Chitosan; colon target; levofloxacin; microspheres; pharmacokinetics; release