Studies On Stability And Pharmacokinetics Of Florfenicol Dual Suspension Emulsions

The content of the florfenicol and its related substance of florfenicol dual suspension emulsions was determined, meanwhile, its stability and pharmacokinetics were researched. which will provide the clinical application and evaluation index of pharmacokinetics for the preparation of the drug.1. Researched and established a system of HPLC-UV methods determining the florfenicol and related substance in FFSE. The mobile phase was acetonitrile-water(32:68), The regressive curve(A=22622xC+2244.6, r=0.9999) was linear between21.04μg/mL and105.2μg/mL and its mean recovery was100.4%(n=9), tR of florfenicol is5.9min and thiamphenicol is3.3min, the separation between thiamphenicol and florfenicol was good.2. The stress testing, accelerated and long-term testing of FFSE were conducted, and determined the primary items such as characteristics, content, pH and related substance according programs of stability test. The results revealed that FFSE was influenced by the light and temperature, but pH and content decreased slightly, and related substance increased a little.3.Researched and established the means of HPLC-UV determining the content in plasma and studied on the pharmacokinetics of FFSE of pigs. The mobile phase was acetonitrile-water(28:72), The regressive curve(A=220561×C+13684, r=0.9996) was linear with the range of21.04μg/mL to105.2μg/mL,and LOQ was0.025μg/mL, and it’s recovery ratio was between84.7%and107.3%, RSD<6%. The results showed that the plasma concentration and time relation were best fitted with one-compartment and1st absorption model after i.m. injection. The main parameters of pharmacokinetics were Cmax(4.5±0.7) μg/mL,tmax(6.3±1.2)h,AUC(0-∞)(124.7±14.4)μg/(mL·h), V1/F(3.3±1.2)L/kg, CL/F(0.16±0.02)L/h/kg. Showed that florfenicol dual suspension emulsions in pigs slowly absorbed, wide distribution, eliminated slowly and the body maintaining longer, which meant a long-term, sustained release purposes.