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1.
The disposition of florfenicol after single intravenous and intramuscular doses of 20 mg of florfenicol/kg of body weight (b.w.) to feeder calves was investigated. Serum florfenicol concentrations were determined by a sensitive high performance liquid chromatographic method with a limit of quantitation of 0.025 μg/ml. The extent of serum protein binding of florfenicol was only 13.2% at a serum florfenicol concentration of 3.0 μg/ml. Serum concentration-time data after intravenous administration were best described by a triexponential equation. Total body clearance and steady state volume of distribution were 3.75 ml/min/kg b.w. and 761 ml/kg b.w., respectively. The terminal half-life after intravenous administration was 159 min. The absolute systemic availability after intramuscular administration was 78.5% (range: 59.3–106%) and the harmonic mean of the terminal half-life was 1098 minutes, indicating slow release of the florfenicol from the formulation at the intramuscular injection site.  相似文献   

2.
Pharmacokinetics of florfenicol 30% injectable solution was determined in lactating cows after intravenous, intramammary and intramuscular administration. Serum concentration-time data generated in the present study were analysed by non-compartmental methods based on statistical moment theory. Florfenicol half-life was 176 min, mean residence time 129 min, volume of distribution at steady-state 0.35 L/kg, and total body clearance 2.7 mL/min·kg after intravenous administration at 20 mg/kg. The absorption after intramuscular administration appeared slow and the kinetic parameters and the serum concentration vs. time curve were characteristic of absorption rate-dependent elimination. The absorption after intramammary administration of florfenicol at 20 mg/kg was good (53.9%) and resulted in serum concentrations with apparent clinical significance. The intramammary administration resulted in serum florfenicol concentrations that were significantly higher than the respective serum concentrations following Intravenous administration 4 h after administration and thereafter. Florfenicol absorption was faster from the mammary gland than from the muscle. The maximum serum concentrations ( C max) were 6.9 μg/mL at 360 min after intramammary administration and 2.3 μg/mL at 180 min after intramuscular administration. The bioavailability of florfenicol was 54% and 38% after intramammary and intramuscular administration, respectively. The C max in milk was 5.4 μg/mL at 180 min after intravenous and 1.6 μg/mL at 600 min after intramuscular administration.  相似文献   

3.
Florfenicol, a monofluorinated analogue of thiamphenicol, has antibacterial activity against a broad spectrum of bacterial strains, including enteric bacteria that are resistant to chloramphenicol and thiamphenicol. The pharmacokinetics of florfenicol was studied following a single intravenous bolus or intramuscular injections at a dose of 20 mg/kg body weight, in five healthy goats. Serum florfenicol concentrations were determined using two analytical methods: microbiological assay and high-performance liquid chromatography (HPLC). Pharmacokinetic analysis was performed using redundant routine equations and the results derived from each method were compared. While florfenicol was detected for up to 4 and 8 h after administration by the bioassay, the drug was recovered in serum after 12 and 24 h by HPLC following intravenous and intramuscular injections, respectively. Comparison of the concentration profiles obtained by the two methods revealed substantial differences in the resultant kinetic data. Values for the initial serum concentration, elimination half-life, the area under the serum concentration-time curve, the mean residence time, and the systemic bioavailability were significantly (P < 0.01) higher when florfenicol concentrations were determined using HPLC. In conclusion, differences between analytical methodologies should be considered when interpreting the kinetic data for clinical use. However, both the hepatic biotransformations and the interchangeability of enantiomers need further investigation.  相似文献   

4.
1. Disposition kinetics were compared in healthy chickens and in chickens naturally infected with E. coli following the intravenous, intramuscular and oral administration of chloramphenicol in a single dose of 20 mg/kg body weight. 2. Lower serum chloramphenicol concentration in diseased chickens were reported after intravenous injection, but they were higher than normal 30 min after intramuscular and oral administration. Following intravenous injection the volume of distribution was increased in diseased chickens. 3. The biological half-life in normal chickens was 8.32 +/- 0.5 h and was prolonged in diseased birds (26.21 +/- 0.2 h). The body clearance of chloramphenicol was reduced in diseased chickens. 4. The rate of absorption of chloramphenicol was delayed after administration via the oral route but the extent of absorption was increased. The maximum concentration was higher and it was reached after a longer time in diseased than in normal chickens after administration by both intramuscular and oral routes.  相似文献   

5.
The pharmacokinetic behavior of chloramphenicol in Chinese spot-billed ducks (Anas poecilorhyncha) was investigated. Single doses of chloramphenicol were given by the intravenous (22 mg/kg), intramuscular (22 mg/kg), and oral route (55 mg/kg) to six, seven and six ducks, respectively. Serum samples were collected at various times and analyzed for chloramphenicol by a radio-enzymatic procedure. The time—concentration curves after intravenous administration were described by one-compartment kinetics. The mean half-lives for the intravenous, intramuscular, and oral route were 102.5, 104.5 and 151.4 min, respectively. There was little individual variation in the time—concentration plots for either the intravenous or intramuscular route. However, following oral administration, there was considerable individual variation indicating erratic absorption. From the intravenously derived, pharmacokinetic parameters, dosage regimens applicable to either the intravenous or intramuscular route, were developed.  相似文献   

6.
1. The pharmacokinetic aspects of orbifloxacin were studied in both healthy and naturally diseased ducks after a single intravenous and intramuscular dose of 5?mg?kg?1 body weight. The serum concentrations of orbifloxacin following single intravenous and intramuscular injections were higher in diseased than in healthy ducks.

2. The disposition of orbifloxacin after a single intravenous injection was described by a two-compartment open model in both healthy and diseased ducks. Orbifloxacin was distributed and eliminated at a significantly slower rate in diseased than in healthy ducks. The total body clearance (ClB) was lower in diseased (0·131?l?kg?1?h?1) than healthy ducks (0·191?l?kg?1?h?1).

3. Following intramuscular administration of orbifloxacin, the peak serum concentration (Cmax) was higher in diseased than in healthy ducks, and this was achieved at a maximum time (tmax) of 1·114 and 0·993?h, respectively. The drug was eliminated at a significant slower rate in diseased ducks (elimination half-life t 0·5( el )?=?5·07?h) than in healthy ducks (elimination half-life t 0·5( el )?=?4·18?h).

4. These results indicate that drug elimination patterns in healthy and diseased ducks are not the same. The pharmacokinetic profile of the drug is altered in diseased ducks due to the increased serum orbifloxacin concentrations compared with clinically healthy ducks. In conclusion, 5?mg?kg?1 body weight of orbifloxacin administered as a single dose once daily could be useful in the treatment of disease caused by Pasteurella multocida pathogen in ducks.  相似文献   


7.
1. Disposition kinetics of doxycycline (doxy) was studied in healthy chickens and chickens experimentally intoxicated with aflatoxin B1 by intravenous, oral or intramuscular (i.m.) injection, in a single dose of 15 mg/kg body weight. In addition, the tissue distribution and residual pattern of the drug were determined in healthy and intoxicated chickens. 2. The maximum serum concentrations of doxy were reached 1.97 and 2.37 h after oral, and 1.57 and 2.92 h after i.m. dosage in healthy and aflatoxic birds, respectively. 3. The volumes of distribution and total body clearances were higher in aflatoxic birds (1.75 l/kg and 14.61 ml/kg/min) than in healthy chickens (0.93 l/kg and 4.6 ml/kg/min). Data relating to intravenous injection were analysed using a two-compartment open model curve fit. 4. Lower values of systemic bioavailability were observed in intoxicated birds (30.9 and 33.9%) than healthy ones (43.7 and 57.3%) after oral and i.m. administration, respectively. 5. The highest concentration of doxy residues were present in liver, kidney and serum followed by heart and muscles. Doxy residue concentrations in edible tissues was below the EEC limit 6 d after cessation of oral or i.m. medication with 15 mg/kg body weight twice daily for 5 successive days.  相似文献   

8.
氟甲砜霉素对鸭大肠杆菌病的药效研究   总被引：1，自引：0，他引：1  
为了探讨氟甲砜霉素对鸭大肠杆菌病的疗效进行了本研究。用试管2倍稀释法测定氟甲砜霉素及对照药氯霉素对大肠杆菌的最小抑菌浓度，然后用氟甲砜霉素，氯霉素进行混饲给药5d的疗效试验，试验结果表明，氟甲砜霉素，氯霉素对大肠杆菌O78株的最小抑菌浓度分别为6mg/L,8mg/L,100,200,400mg/kg氟甲砜霉素混饲给药对鸭大肠杆菌病的有效率分别为30．3％，93．9％，100％,400mg/kg氯霉素的有效率为93．9％，试验各组之间鸭的增重差异不显著。  相似文献   

9.
新型兽用纳米乳载药系统在大鼠体内的药代动力学研究   总被引：1，自引：1，他引：0  
为了解氟苯尼考纳米乳(FFNE)在大鼠体内药代动力学行为,本试验以氟苯尼考溶液(FFSol)为参比制剂,以30 mg/kg剂量给大鼠灌胃和肌内注射给药,分别于给药后0.5、1、2、4、8、12、24、36、48、72 h采血,利用高效液相色谱法测定血浆中氟苯尼考含量,利用DAS 2.0软件计算房室模型与非房室模型条件下药代动力学参数。结果显示,在两种给药方式下,FFNE与FFSol在大鼠体内均符合二室模型。灌胃给药后,FFNE与FFSol在房室模型条件下AUC(0-∞)分别为1 085.047和2 176.490 mg/L·h,半衰期分别为10.566和13.687 h,FFNE的相对生物利用度为187.4%。肌内注射给药后,FFNE与FFSol在房室模型条件下AUC(0-∞)分别为1 530.55和3 243.338 mg/L·h,半衰期分别为7.533和13.335 h,FFNE的相对生物利用度为211.9%。结果表明,FFNE通过灌胃和肌内注射给药在大鼠体内分布较广,灌胃相对肌内注射吸收差,消除快。将氟苯尼考制成纳米乳剂后促进了氟苯尼考的吸收,氟苯尼考的生物利用度显著提高。  相似文献   

10.
A study on the bioavailability and pharmacokinetics of florfenicol was conducted in six healthy dogs following a single intravenous (i.v.) or oral (p.o.) dose of 20 mg kg(-1) body weight (b.w.). Florfenicol concentrations in serum were determined by a high-performance liquid chromatography/mass spectrometry. Plasma concentration-time data after p.o. or i.v. administration were analyzed by a non-compartmental analysis. Following i.v. injection, the total body clearance was 1.03 (0.49) L kg(-1)h(-1) and the volume of distribution at steady-state was 1.45 (0.82) L kg(-1). Florfenicol was rapidly distributed and eliminated following i.v. injection with 1.11 (0.94)h of the elimination half-life. After oral administration, the calculated mean C(max) values (6.18 microg ml(-1)) were reached at 0.94 h in dogs. The elimination half-life of florfenicol was 1.24 (0.64) h and the absolute bioavailability (F) was achieved 95.43 (11.60)% after oral administration of florfenicol. Florfenicol amine, the major metabolite of florfenicol, was detected in all dogs after i.v. and p.o. administrations.  相似文献   

11.
The pharmacokinetic properties of difloxacin following intravenous (i.v.) and intramuscular (i.m.) administration in goats were investigated. Difloxacin was administered in a single dose of 5 mg/kg body weight for both routes and was assayed in biological fluids (serum and urine) to determine its concentrations, kinetic behaviour and systemic availability. Following a single i.v. injection, the serum difloxacin level was best approximated to follow a two-compartment open model using weighted non-linear regression analysis. The elimination half-life (t1/2 beta) was 6.3 +/- 0.11 h. The volume of distribution at steady-state (Vdss) was 1.1 +/- 0.012 L/kg and the total body clearance (Cltot) was 0.13 +/- 0.001 L/kg/h. Following a single i.m. administration, difloxacin was rapidly absorbed and the mean peak serum concentration (4.1 +/- 0.23 micrograms/ml) was achieved 1 h post administration. The extent of serum protein binding of difloxacin in goats was 13.79 +/- 1.02% and the systemic availability was 95.4 +/- 1.17%. Following i.m. injection of difloxacin at a dose rate of 5 mg/kg b.wt for 5 consecutive days, the drug could not be detected in serum and urine at 4th day from the last injection.  相似文献   

12.
Some Pharmacokinetic Data for Danofloxacin in Healthy Goats   总被引：4，自引：0，他引：4  
The pharmacokinetics of danofloxacin was determined in five clinically normal adult female goats after intravenous (IV) or intramuscular (IM) doses of 1.25 mg/kg body weight. Blood and urine samples were collected from each animal at precise time intervals. Serum and urine concentrations were determined using microbiological assay methods and the data were subjected to kinetic analysis. After intravenous injection, the serum concentration–time curves of danofloxacin were characteristic of a two-compartment open model. The drug was rapidly distributed and eliminated with half-lives of 17.71±1.38 min and 81.18±3.70 min, respectively. The drug persisted in the central, highly perfused organs with a K 12/K 21 ratio of 0.67±0.25. The mean volume of distribution at a steady state (V dss) was 1.42±0.15 L/kg. After intramuscular administration, the serum concentration peaked after 0.58±0.04 h at approximately 0.33±0.01 g/ml. While danofloxacin could be detected in serum for 4 and 6 h, it was recovered in urine for up to 24 and 72 h after IV and IM administration, respectively. The systemic bioavailability after IM injection was 65.70%±10.28% and the serum protein-bound fraction was 13.55±1.78%.  相似文献   

13.
Disposition kinetics of danofloxacin and ciprofloxacin in broiler chickens.   总被引：3，自引：0，他引：3  
Disposition kinetics of danofloxacin and ciprofloxacin were studied in broiler chickens following intravenous, intramuscular and oral administration in a single dose of 5 and 10 mg/kg-1 body weight respectively. In addition, tissue distribution and residual pattern of both drugs were determined. The maximum serum concentration (Cmax) after intramuscular and oral administration were 1.03 and 0.55 mu/ml for danofloxacin and 2.92 and 1.24 mu/ml for ciprofloxacin attained at 0.8 and 2.43 and 0.55 and 1.27 hours for danofloxacin and ciprofloxacin respectively. The volume of distribution and systemic bioavailability were higher for danofloxacin (Vdss 2.21 L/kg and F% 96.56 and 81.4%) as compared with ciprofloxacin (Vdss 1.41 L/kg and F% 75.5 and 29.4%). Data relating to intravenous injection for both drugs were analyzed using a two compartment open model curve fit. Danofloxacin and ciprofloxacin were not detected in the serum of broilers at the 5th and 3rd day respectively following the drugs withdrawal while were detected in liver, kidneys, spleen and lungs. Danofloxacin completely disappeared from all tissues at the 13th day after stopping of the drug medication but ciprofloxacin disappeared after 5 days only.  相似文献   

14.
1. Florfenicol (30 mg/kg body weight) was administered to broiler chickens via intravenous (iv), intramuscular (im) and oral routes to study its plasma concentrations, kinetic behaviour, systemic bioavailability and tissue content.

2. Following a single iv injection, the kinetic disposition of florfenicol followed a 2‐compartmental open model with an elimination half‐life of 173 min, total body clearance of 26.9 ml/kg/min and a steady state volume of distribution of 5.11 1/kg.

3. The highest plasma concentrations of florfenicol were 3.82 and 3.20 μg/ml following single im and oral administration, respectively. The systemic bioavailability was 96.6% and 55.3% after im and oral administration. The plasma protein binding of florfenicol was 18.5%.

4. Following its administration, the highest tissue concentrations of the drug were found in the kidney bile, lung, muscle, intestine, heart, liver, spleen and plasma. Low concentrations of the drug were found in brain, bone marrow and fat. No florfenicol residues were detected in tissues and plasma after 72 h except in the bile from where it disappeared after 96 h.  相似文献   


15.
The single-dose disposition kinetics of florfenicol was determined in healthy, non-lactating Egyptian goats, after its intravenous (i.v.) and intramuscular (i.m.) administration at 20 mg kg-1 b.wt. Drug concentrations in serum and urine were determined using microbiological assay method and data was subjected to a kinetic analysis. Florfenicol concentrations in serum decreased in a bi-exponential manner after intravenous administration with distribution (t1/2 alpha) and elimination (t1/2 beta) half-lives of 10.256 +/- 0.938 and 56.237 +/- 3.102 minute, respectively. The steady-state volume of distribution (Vdss) and total body clearance (Cltot) were 3.413 +/- 0.304 l kg-1 and 3.306 +/- 0.333 l kg h-1. After intramuscular administration, the peak serum concentration (Cmax) was 0.859 +/- 0.025 micrograms ml-1, achieved at (Tmax) 1.220 + 0.045 h. Florfenicol was detected in urine up to 24 and 96 hour after i.v. and i.m. administration, respectively. The extent of the protein binding and systemic bioavailability of florfenicol were 22.45 +/- 1.727% and 65.718 +/- 3.372%, respectively.  相似文献   

16.
The pharmacokinetics of florfenicol and its metabolite, florfenicol amine, was investigated after its intravenous (i.v.) and oral (p.o.) administration of 20 mg/kg of body weight in Korean catfish (Silurus asotus). After i.v. florfenicol injection (as a bolus), the terminal half-life (t(1/2)), the volume of distribution at steady state (V(dss)), and total body clearance were 11.12 +/- 1.06 h, 1.09 +/- 0.09 L/kg and 0.07 +/- 0.01 L x kg/h respectively. After p.o. administration of florfenicol, the t(1/2), C(max), t(max) and oral bioavailability (F) were 15.69 +/- 2.59 h, 9.59 +/- 0.36 microg/mL, 8 h and 92.61 +/- 10.1% respectively. Florfenicol amine, an active metabolite of florfenicol, was detected in all fish. After i.v. and p.o. administration of florfenicol, the observed C(max) values of florfenicol amine (3.91 +/- 0.69 and 3.57 +/- 0.65 mg/L) were reached at 0.5 and 7.33 +/- 1.15 h. The mean metabolic rate of florfenicol amine after i.v. and p.o. administration was 0.4 and 0.5 respectively.  相似文献   

17.
Plasma distribution and elimination of florfenicol in channel catfish were investigated after a single dose (10 mg/kg) of intravenous (i.v.) or oral administration in freshwater at a mean water temperature of 25.4 °C. Florfenicol concentrations in plasma were analyzed by means of liquid chromatography with MS/MS detection. After i.v. florfenicol injection, the terminal half-life (t(1/2)), volume of distribution at steady state (V(ss)), and central volume of distribution (V(c)) were 8.25 h, 0.9 and 0.381 L/kg, respectively. After oral administration of florfenicol, the terminal t(1/2), C(max), T(max), and oral bioavailability (F) were 9.11 h, 7.6 μg/mL, 9.2 h, and 1.09, respectively. There was a lag absorption time of 1.67 h in oral dosing. Results from these studies support that 10 mg florfenicol/kg body weight in channel catfish is an efficacious dosage following oral administration.  相似文献   

18.
The pharmacokinetic properties and local tolerance of three oxytetracycline formulations, one conventional (Engemycine, 10%) and two long-acting (Oxyter LA, 20% and Terramycin LA, 20%) were compared in clinically healthy cross-bred pigs following intramuscular injection of single doses (20 mg/kg body weight) in the neck region. Non-compartmental methods were used to calculate the pharmacokinetic parameters. Assessment of local tolerance was based on serum creatine phosphokinase (CPK) concentration and a combination of echographical, macroscopic and histological examinations of the intramuscular injection site. Statistically significant differences (one-way analysis of variance, F-test) were obtained between the three formulations in peak plasma concentration, peak time and mean residence time. Area under the curve did not differ significantly between the formulations. Using the Students t-test for paired data, the two long-acting formulations differed significantly in peak plasma concentration and peak time. Both of the long-acting formulations differed significantly from the conventional formulation in the peak time and mean residence time. All three formulations produced an increase in serum CPK concentrations. The increase in CPK concentration was present from 6 to 24 h post treatment for Terramycin LA, from 6 to 72 h for Oxyter LA and from 6 to 96 h for Engemycine (the conventional formulation). Echographical examination of the injection site showed lesions of an inflammatory type up to 96 h after IM injection of the drug products, whereas from 7 days the lesions represented primarily scar formation. Histological examination of tissue from the injection site did not correlate with echographical scores. The results obtained in this study show that the long-acting formulations provide significantly longer mean residence times of oxytetracycline than the conventional formulation, and that local tolerance at the IM injection site was similar for all three formulations under the experimental conditions used in this study. It can be concluded that the longacting formulations provide the advantage of a longer dosage interval when administered to pigs by intramuscular injection in the neck region at a dose of 20 mg/kg body weight.  相似文献   

19.
The bioavailability and pharmacokinetic disposition of florfenicol in broiler chickens were investigated after intravenous (i.v.), intramuscular (i.m.) and oral administrations of 15 and 30 mg/kg body weight (b.w.). Plasma concentrations of florfenicol were determined by a high performance liquid chromatographic method in which plasma samples were spiked with chloramphenicol as internal standard. Plasma concentration-time data after i.v. administration were best described by a two-compartment open model. The elimination half-lives were 168 +/- 43 and 181 +/- 71 min, total body clearance 1.02 +/- 0.17 and 1.02 +/- 0.16 L x kg/h, the volume of distribution at steady-state 4.99 +/- 1.11 and 3.50 +/- 1.01 L/kg after i.v. injections of 15 and 30 mg/kg b.w., respectively. Plasma concentration-time data after i.m. and oral administrations were adequately described by a one-compartment model. The i.m. bioavailability and the oral bioavailability of florfenicol were 95, 98 and 96, 94%, respectively, indicating that florfenicol was almost absorbed completely after i.m. and oral administrations of 15 and 30 mg/kg b.w.  相似文献   

20.
Holmes, K., Bedenice, D., Papich, M. G. Florfenicol pharmacokinetics in healthy adult alpacas after subcutaneous and intramuscular injection. J. vet. Pharmacol. Therap.  35 , 382–388. A single dose of florfenicol (Nuflor®) was administered to eight healthy adult alpacas at 20 mg/kg intramuscular (i.m.) and 40 mg/kg subcutaneous (s.c.) using a randomized, cross‐over design, and 28‐day washout period. Subsequently, 40 mg/kg florfenicol was injected s.c. every other day for 10 doses to evaluate long‐term effects. Maximum plasma florfenicol concentrations (Cmax, measured via high‐performance liquid chromatography) were achieved rapidly, leading to a higher Cmax of 4.31 ± 3.03 μg/mL following administration of 20 mg/kg i.m. than 40 mg/kg s.c. (Cmax: 1.95 ± 0.94 μg/mL). Multiple s.c. dosing at 48 h intervals achieved a Cmax of 4.48 ± 1.28 μg/mL at steady state. The area under the curve and terminal elimination half‐lives were 51.83 ± 11.72 μg/mL·h and 17.59 ± 11.69 h after single 20 mg/kg i.m. dose, as well as 99.78 ± 23.58 μg/mL·h and 99.67 ± 59.89 h following 40 mg/kg injection of florfenicol s.c., respectively. Florfenicol decreased the following hematological parameters after repeated administration between weeks 0 and 3: total protein (6.38 vs. 5.61 g/dL, P < 0.0001), globulin (2.76 vs. 2.16 g/dL, P < 0.0003), albumin (3.61 vs. 3.48 g/dL, P = 0.0038), white blood cell count (11.89 vs. 9.66 × 103/μL, P < 0.044), and hematocrit (27.25 vs. 24.88%, P < 0.0349). Significant clinical illness was observed in one alpaca. The lowest effective dose of florfenicol should thus be used in alpacas and limited to treatment of highly susceptible pathogens.  相似文献   

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