Preparation Of Florfenicol Nano-agents And Its Pharmacodynamics Evaluation

Florfenicol is a synthetic third-generation animal dedicated chloramphenicol novel broad-spectrum antibiotic is thiamphenicol single fluorine derivative with a broad spectrum antibiotic, absorption, widely distributed in the body and no potential aplastic anemia role, but also non-carcinogenic, teratogenic and mutagenic and other fine features, but the product poor water solubility, low bioavailability, limiting its use in a veterinary clinic. In this study, combined with ultrasonic method and high pressure homogenization method, florfenicol prepared novel nano-formulations, and evaluate the quality of the preparation, in vitro antibacterial pharmacokinetics testing, safety testing and drug testing.1. Nano formulation Florfenicol:Weigh 2g florfenicol added 3ml of Tween-80, add water, mix and dilute to 60ml; ultrasonic probe 8000r/min after treatment 10min, poured into a high-pressure homogenizer homogeneous machine, each 5min pressure 200bar; solution tank to be clarified, bubble disappears, pressure to 1000bar, adding 20mL of dimethylformamide; 1600bar, then the solution was added slowly 20ml of propylene glycol, uniformly stirred to give no transparency florfenicol nano formulations; autoclave 30min, through the membrane seal, temperature preservation.2. Evaluation of the quality of florfenicol nanometer preparation:Determination of florfenicol content using high performance liquid chromatography. the mobile phase was acetonitrile:water ?23:77.v/v?,two batches of florfenicol nano formulations in the range of 90.0%-110.0%florfenicol standard product of, RSD is far less than 1.5%. consistent with the main peak retention time; observe florfenicol nano formulation under TEM, florfenicol into irregular spherical particle size less than 100nm, distribution, and no aggregation phenomena; stability tests showed:florfenicol test nano formulation factors ?temperature, light, frozen?,6 month accelerated testing ?temperature of 40±2?, relative humidity of 75±5%? and 12 months for long-term test ?temperature of 25±2?, relative humidity of 65±5%?, the formulation having a higher stability, but its light and high temperature PH drug content and to a certain extent.3. Antibacterial Nano florfenicol formulations:respectively florfenicol injection ?specification 100ml:5g; 100mL:2g? as a control group. The preparation of nano florfenicol five bacteria ?E. coli, Salmonella. Staphylococcus aureus, Streptococcus and Pasteurella? the minimum inhibitory concentration ?MIC? and minimum bactericidal concentration ?MBC?. The results showed that:florfenicol nanometer by changing the dosage formulation, particle size small, wide dispersion, contact with a great chance of bacteria, its antibacterial effect will be significantly better than the control group.5 clock above the minimum inhibitory concentration of bacteria were in the control group florfenicol injection ?specification 100ml:5g;100mL:2g? 1/2,1/4,1/2,1/4,1/21/2,1/2,1/2,1/2,1/4;Streptococcus minimum bactericidal concentrations of 1/2,1/2 in the control group, no significant difference in other bacteria.4. Nano formulation Florfenicol safety evaluation:The florfenicol injection ?specification 100ml:5g;100mL:2g? as the control group, acute toxicity, irritation ?irritation and abdominal muscle stimulation?, the heat source and other tests of hemolytic florfenicol formulations nano safety evaluation. The results showed that:florfenicol nano formulations in mice LD50 of 428.6mg/kg, LD5095% confidence limit of 420.7?436.6mg/kg,Slightly higher than florfenicol injection ?specification 100mL:5g? LD50 ?415.3mg/kg?, as florfenicol injection ?specification 100mL:2g? LD50 ?146.3mg/kg? three times, is recommended clinical dosage ?20mg/kg? of 21.43 times; Muscle stimulation 0, no peritoneal irritation and pyrogenic, haemolysis reaction.5. Pharmacokinetics of florfenicol detector Nano preparation:the establishment of a plasma florfenicol Determination by HPLC, conducted in rabbits the pharmacokinetic study of nano-formulations of florfenicol. Column:XSELECTTM HSS T3 column,150mm× 2.1mm, particle size of 5 m; mobile phase:acetonitrile:water ?23:77,v/v?; flow rate 1.0mL/ min; column temperature 40?; detection wavelength of 224mn;injection volume:20?l. Florfenicol at a concentration of 0.8?g/ml?15?g/ml range a good linear regression equation A= 21715.5 x C-863.2633, the correlation coefficient R=0.9998610?n=6?, the minimum detectable concentration of 0.8?g/ml, the extraction recoveries between 92.3-105.4%, RSD is less than 6%. use winnonlin₅.2.1 version pharmacokinetics software program, get pharmacokinetic parameters:Cmax8.32±1.26?g/mL, Tmax0.88±0.14h, AUC ?o-?? 20.46±2.69?g/mL±h, T 1/22.37±1.10 h.The results showed that:florfenicol nano formulations in rabbits with a rapid absorption, metabolism, fast, wide distribution, the characteristics of rapid therapeutic effect.