Comparison of ciprofloxacin pharmacokinetics after i.v. and i.p. administration. (A) Levels of free (•,▪) or liposomal (▴,⧫) ciprofloxacin in plasma after i.v. (•,▴) or i.p. (▪,⧫) administration. Liposomes were composed of SM/chol, and the dose of ciprofloxacin injected for all groups was 15 mg/kg. (B) Ciprofloxacin/lipid ratios in plasma after i.v. (▴) or i.p. (⧫) administration of ciprofloxacin encapsulated in SM/chol liposomes. Data represent means ± standard errors from three mice.