preparation of cefquinome sulfate proliposome and its pharmacokinetics in rabbit

cefquinome sulfate (cs) is a fourth-generation cephalosporin, which has been developed solely for veterinary use. it shows potent antibacterial activity against a broad spectrum of bacterial species. however, cefquinome is susceptible to hydrolysis, which limiting its clinical employment efficacies to some extent. so, in this study, to increase cefquinome sulfate biological half-life, a novel cefquinome sulfate proliposome was prepared by solid dispersion and effervescent techniques and characterized for morphology, particle size, entrapment efficiency and in vitro release. a reversed phase-high performance liquid chromatography (rp–hplc) method was first chosen and established to determine the drug concentration in plasma after intra muscular (im) administrating cefquinome sulfate solution and liposome at a single dosage of 18 mg/kg in rabbit. then their pharmacokinetics in vivo was compared. results showed that the received liposome was milky white suspension, spherical or ellipsoidal in shape. the mean particle size was 203±5 nm and the entrapment efficiency was 53.5±0.16%. the cefaquinom sulfate solution and liposome both followed a two compartment model, in vivo. the pharmacokinetic parameters for the solution and liposomal formulations were measured as follows: t1/2α were (1.214 ± 0.135) h and (1.395 ± 0.113) h, t1/2β were (8.752 ± 0.846) h and (16.503 ± 1.275) h, auc(0-24) were (49.582 ± 9.173) (mg·h)/l and (138.727 ± 11.034) (mg·h)/l, cl/f were (0.357 ± 0.015) l/(h·kg) and (0.127 ± 0.012) l/(h·kg), mrt(0-24) were (2.68 ± 0.229) h and (5.945 ± 0.479) h, respectively. it could be clearly seen that t1/2β of liposome prolonged (p < 0.05), auc and mrt both increased remarkably (p < 0.01), cl/f decreased. results indicated that this preparation has more residence time and exhibits some sustained–release tendency.