Preparation and evaluation of danofloxacin mesylate microspheres and its pharmacokinetics in pigs.

Danofloxacin mesylate gelatin microspheres (DFM-GMS) were prepared by an emulsion chemical crosslinking technique. Distribution of particle size, morphologic characteristics, drug content, and drug stability were evaluated. In-vitro study showed that the release of danofloxacin mesylate (DFM) from microspheres was much slower than from the raw material (DFM) in the release medium. Pharmacokinetic characteristics were evaluated following intramuscular injection of DFM-GMS or DFM in pigs at dosage of 2.5 mg/kg body weight. Elimination half-life (t(1/2β)) of the drug was 24.32 h for DFM-GMS, and 6.61 h for DFM (P < 0.01). Overall, DFM-GMS could be applied as a long-acting and lung targeting dosage form of DFM for clinical application.