The Preparation Of Profound Ceftiofur Long-acting Injection And Its Pharmacokinetic Study

The experiment is for the purpose of studying the development method of the profound ceftiofur long-acting injection and its pharmacokinetics ,to provide theory basis for the development method of long-acting and clinical reasonale medication.The best ratio of ceftiofur and sulbactam was screened by minimal inhibitory concentration(MIC) and minimal bactericidal concentration(MBC) examined by in vitro antibacterial experiment.The profound ceftiofur long-acting injection is prepared by dispersion method,and the prescription is studied according to the orthogonal design of experiments.the ratio of suspending agent , phosphatide and span-80 is being adjusted to make the nature of suspension more stable in accordance with the ratio of sedimentation volume and redispersibility when the content of other adjuvant is determined.the result showed that the suspension could have stablest nature in the ratio of sedimentation volume and redispersibility just as the ratio of the three factors is most reasonable.In the research of the pharmacokinetics,the plasma concentration of sulbactam,ceftiofur and all desfuroylceftiofur-related metabolities were measured by high-performance liquid chromatography.Recovery and precision of the method was all excellent.The standard curve was linear in the range of 0.25~40μg/ml of sulbactam and ceftiofur and its metabolities.Pharmacokinetics and bioavailability were carried out in rabbits after a single intramuscular administration of the ceftiofur long-acting injection,the profound ceftiofur long-acting injection made by ourselves ,and market ceftiofur injection.the results of pharmacokinetics showed that the bioavailability, the peak time and the half-life time of the prolonged action injection of profound ceftiofur and market ceftiofur is 89.43%, 56.2%,1.47h,0.69h, 15.53h,9.32h respectively.the profound ceftiofur long-acting injection sustanined-release preparations,and it could make its bioavailability advanced.The preparation of the profound ceftiofur long-acting injection is the first case in domestic,the grade estimation,the pharmacokinetics study and the bioavailability suggest that the prolonged injection has good stability ,prolonged action ,slow–release and other merits,and possess satisfactory exploitation and application prospect.