The Pharmacokinetic Characteristics Of Lincomycin And Gentamicin Compound Injection In PIG

Swine streptococcosis is an acute and febrile anthropo zoonosis caused by pathogenic Streptococcus,it not only can cause pig meningitis, arthritis and endocarditis,etc,but also can infect specific populations and cause disease even death.In recent years,swine streptococcus seriously threaten the development of swine industry and the health of employees with a rising incidence, especially the Swine streptococcosis caused by Streptococcus suis type 2 has become an important disease which once again caused worldwide and public health concern after the avian flu, SARS, Nipah disease.As more of Streptococcus suis serotypes,a wide spectrum of drug resistance and drug resistance impacted by serotypes and regional disparity, So look for new combination technology, increasing drug efficacy and inhibiting the production of resistant strains has become the major research directions to treat swine streptococcosis in domestic and international. Lincomycin and gentamicin compound injection is a new composition of antibiotic compound to specialized treat swine streptococcosis which was developed by Northeast Agricultural.It consists of an effective amount of lincomycin hydrochloride and gentamicin sulfate components, mainly used for treating the streptococcal infection in weaned piglets. In vitro pharmacodynamic studies have shown that the combination of lincomycin hydrochloride and gentamicin sulfate can significantly improve the efficacy of swine streptococcosis, and can reduce the incidence of drug reactions and side effects toxicity, but it is not clear the effect in in vivo,so we will start the study on the blood pharmacokinetic characteristics of Lincomycin and gentamicin compound injection in swine.In this study, 18 piglets were divided into 3 groups, and neck muscles were injected with same doses of Lincomycin and gentamicin compound injection, injection lincomycin and gentamicin injection.The plasma concentrations were tested and pharmacokinetic compartment mode was calculated after collecting blood samples at different time points.By comparing the pharmacokinetics differences between compound injection and the latter two and calculating the relative bioavailability to study the pharmacokinetic characteristics of compound injection of two drugs. This provide a theoretical basis to guide reasonable clinical medication, reduce the incidence of adverse reactions, ensure drug safety and prevent the outbreak of swine streptococcosis.This study established a sensitive high performance liquid chromatography which can simultaneously test the plasma concentrations of lincomycin and gentamicin, the current research on this aspect has not been reported.The results showed that lincomycin hydrochloride and gentamicin sulfate has a good linear relationship at 0.5~50μg / mL and 0.33~33μg / mL, the R2 is 0.9994 and 0.9996, respectively; the with-day and be-tween-day precision in pig plasma samples were less than 5% and 8%; .The recoveries of them were 90.85% and 88.43%; The method has limit of quantification detection limits were 0.5μg / mL and 0.33μg / mL. respective for lincomycin hydrochloride and gentamicin sulfate.In this study, the main blood pharmacokinetic parameters were compared between combined drugs and separate administration. According to the analysis of comparative parameters,the two drugs combined in compound injection changed the pharmacokinetic profile of lincomycin hydrochloride in vivo, the combination slows down the absorption rate of lincomycin hydrochloride, reduced its peak concentration, and promote its elimination in the body; but the influence of gentamicin pharmacokinetic characteristics was not obvious only slow down the absorption rate.We study the relative bioavailability of lincomycin hydrochloride and gentamicin sulfate of compound injection in pigs,the results show that the relative bioavailability of gentamicin sulfate was 103.54%,while the relative bioavailability of lincomycin hydrochloride was 79.44%.