In vitro and in vivo evaluation of levofloxacin sustained-release capsules.

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.

MATERIALS AND 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%.

CONCLUSION

Statistical analysis indicated that the capsules containing Surelease-coated pellets had a satisfactory sustained-release behavior and a desired pharmacokinetic property.