title: In vitro and in vivo evaluation of levofloxacin sustained-release capsules.
abstract: OBJECTIVE
  To reduce the frequency of administration and improve patient compliance, novel levofloxacin sustained-release capsules with suitable in vitro release profiles and good bioavailability were developed.
  
  
  METHODS
  A fluidized bed was used to prepare levofloxacin pellets by spraying the drug solution onto blank pellets. Then the pellets were coated with either Surelease water dispersion or Eudragit® NE30D water dispersion to achieve sustained-release characteristics. The mixed pellets containing 15% of the uncoated pellets and 85% of the coated pellets were filled into the hard gelatin capsules. In vitro release test was performed with the capsules. A single-dose pharmacokinetic study of the capsules was carried out in beagle dogs.
  
  
  RESULTS
  Although Eudragit® NE30D-coated pellets and Surelease-coated pellets showed similar sustained-release profiles in vitro, their in vivo pharmacokinetic characteristics exhibited significant difference. Unsuccessful in vivo-in vitro correlation was shown in Eudragit® NE30D-coated pellets with a relative bioavailability of only 41.5%, whereas Surelease-coated pellets achieved best sustained-release feature both in vitro and in vivo with a relative bioavailability of 103.0%.
  
  
  CONCLUSIONS
  Statistical analysis indicated that the capsules containing Surelease-coated pellets had a satisfactory sustained-release behavior and a desired pharmacokinetic property.
authors.affiliation: School of Pharmacy, China Pharmaceutical University, Nanjing, PR China.
authors.forename: Li-Fang
authors.initials: LF
authors.lastname: Yin
authors.forename: Shi-Jing
authors.initials: SJ
authors.lastname: Huang
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Jiang
authors.forename: Chun-Jie
authors.initials: CJ
authors.lastname: Zhao
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Pei
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001682:Biological Availability; D002214:Capsules / Q000737:chemistry; D002482:Cellulose / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004285:Dogs; D004334:Drug Administration Schedule; D004343:Drug Implants / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D064704:Levofloxacin; D008297:Male; D015242:Ofloxacin / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics*; D012995:Solubility; D013678:Technology, Pharmaceutical
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D004343:Drug Implants; D005079:Excipients; D064704:Levofloxacin; C013517:ethyl cellulose; D002482:Cellulose; D015242:Ofloxacin