恩诺沙星在鸡内服和肌肉注射给药后的排泄研究

恩诺沙星是动物专用的氟喹诺酮类药物。动物内服和注射恩诺沙星后，部分在肝脏脱乙基，代谢为环丙沙星，主要经肾排泄，也有一部分经胆汁排泄。本文旨在研究鸡给予恩诺沙星后，原形和活性代谢产物环丙沙星的排泄规律，为研究合理用药、制订畜禽养殖业污物排放标准及兽药的环境风险评估等提供科学依据。     

恩诺沙星在鸡体中的排泄及其在鸡粪中的降解

检测了在不同给药剂量下,健康鸡服用恩诺沙星后,在不同时间粪尿中恩诺沙星及其主要代谢产物的含量变化,并对在不同光照条件下鸡粪中恩诺沙星的降解进行了研究。结果表明,健康鸡灌服恩诺沙星后,主要以恩诺沙星原形、其次以环丙沙星的形式随粪(尿)排出体外。2.5 mg/kg体重剂量组和5 mg/kg体重剂量组在给药后6h恩诺沙星的排泄量达到最高峰;环丙沙星达到峰浓度的时间为4 h。7.5 mg/kg体重剂量组恩诺沙星排泄量达到最高峰的时间为9 h;环丙沙星达到峰浓度的时间为6 h。至给药后第10天时鸡粪中检不出恩诺沙星和环丙沙星。鸡粪中恩诺沙星的降解速率受光照条件的影响,在避光条件下,鸡粪中恩诺沙星几乎很少降解;在自然光照下,鸡粪中恩诺沙星的降解较快,其变化趋势符合一级动力学方程Ct=C0e-kt,并由此求得鸡粪中恩诺沙星在自然光照下的降解半衰期为(2.23±0.25)d。     

恩诺沙星及其代谢物环丙沙星在猪粪便及尿液中的排泄研究

给猪连续3d饲喂含无味恩诺沙星的饲料后，对其排泄的粪便和尿液进行了药物含量测定结果表明，粪便和尿液中恩诺沙星及其代谢产物环丙沙星的排泄量都比较高，粪便中排泄的药物浓度显著高于尿液中药物排泄的浓度，停止给药后第15天，在猪粪中可检测到恩诺沙星，停止给药后第10天，猪尿液中可检测到环丙沙星。     

猪静注隐丹参酮尿药排泄分析

６头猪单剂量静注隐丹参酮后,收集自然排出的尿液,以后相高压液相色谱法检测隐丹参酮及其活性代谢物丹参酮ⅡＡ在尿中的浓度,分时间段计算排泄量及排泄总量,并计算排泄量占给药量的百分比,结果表明,在测定时间内,尿中隐丹参酮排泄量平均为０．２３７６％,丹参酮ⅡＡ排泄量为０．０９５２％     

恩诺沙星长效注射液肌注后在猪体内的药动学研究

研究了恩诺沙星长效注射液给猪肌注后的药物动力学特征。将12只白猪随机分成两组,每组6只,分别肌注恩诺沙星注射液(5mg/kg)和长效恩诺沙星注射液(18.75mg/kg),并于给药后0.1, 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 60h, 从前腔静脉采取5ml血,用HPLC分析各血浆样品中的药物浓度,用MCPKP软件计算药动学参数。结果表明:长效恩诺沙星注射液肌注后,经5.64h达到4.86μg/ml的最高浓度,吸收半衰期和消除半衰期分别为2.42h和19.47h,有效浓度维持时间为128.73h, AUC为166.96mg/L.h。吸收半衰期显著延长(p<0.05),达峰时间极显著推迟(p<0.01),消除半衰期也显著长于恩诺沙星注射液。     

鸡猪排泄物中恩诺沙星和环丙沙星含量HPLC检测方法的建立

建立了测定鸡、猪排泄物中恩诺沙星及环丙沙星含量的高效液相-荧光检测方法.将猪粪和鸡粪尿混合物样品分别用甲醇氨水溶液和醋酸甲醇溶液浸提,猪尿用固相萃取小柱富集净化,流动相为乙腈-三乙胺磷酸溶液（0.02 mol/L）,荧光激发波长280 nm,发射波长450 nm.检测结果表明,排泄物样品中恩诺沙星和环丙沙星含量的检测定量限,鸡粪尿混合物为0.010 μg/g,猪尿0.005 μg/mL,猪粪为0.020 μg/g.外标法标准曲线的线性范围鸡粪尿混合物中恩诺沙星为0.010～100.000 μg/g、环丙沙星为0.010～50.000 μg/g,猪尿和猪粪中恩诺沙星和环丙沙星的线性范围分别为0.005～0.500 μg/mL和0.020～1.000 μg/g.恩诺沙星和环丙沙星的回收率分别大于75%和88%.HPLC方法的样品前处理和检测方法简便、快捷,准确性较微生物检测法高.     

猪排泄物中恩诺沙星和环丙沙星含量的HPLC检测方法

为了对猪排泄物中恩诺沙星(enrofloxacin,ENR)和环丙沙星(ciprofloxacin,CIP)进行定量检测,试验建立了测定猪粪尿中ENR和CIP含量的高效液相－荧光检测方法。将猪粪经乙腈－氨水超声提取后,加入三氯乙酸酸化,然后分别将经磷酸酸化后的猪尿和提取后的猪粪溶液经固相萃取小柱富集净化,取净化液进行HPLC分析。HPLC流动相为乙腈(A):柠檬酸/乙酸铵缓冲液(B),梯度洗脱:0~25 min,A 10%~40%;25~30 min,A 40%至10%,荧光检测器的激发波长278 nm,发射波长465 nm。结果表明,ENR和CIP 在尿中的最低检测限(LOD)<0.01 mg/L,在粪中的LOD<0.021 mg/kg,在尿中的最低检测限(LOQ)<0.03 mg/L,在粪中LOQ<0.056 mg/kg,猪尿中的ENR和CIP在0.01~1.0 mg/mL范围内线性关系良好,R²分别为0.9994和0.9992;猪粪中的ENR和CIP在0.02~2.0 mg/mL范围内线性关系良好,R²分别为0.9986和0.9981。ENR在猪粪和猪尿中的回收率分别为79.4%和88.5%,CIP在猪粪和猪尿中的回收率分别为75.8%和89.9%。该方法样品处理简单,检测结果准确可靠,且灵敏度较高,是值得推广的检测方法。     

猪口服隐丹参酮排泄数据分析

给猪单剂量（４０ｍｇ／ｋｇ）口服隐丹参酮（ｃｒｙｐｔｏｔａｎｓｈｉｎｏｎｅ,ＣＴ后）,收集尿液,引流胆汁,以高效液相色谱（ＲＰ－ＨＰＬＣ）法检测ＣＴ和活性代谢物丹参酮ⅡＡ（ｔａｎｓｈｉｎｏｎｅⅡＡ,ＴＳ）的浓度,分时间段计算排泄量、累积排泄量及排泄率。结果,在４８ｈ内尿液中ＣＴ及ＴＳ排汇率无很低,分别为０．００２３％和０．０００６％;ＣＴ及ＴＳ在胆汁中的浓度随给药时间的延长逐渐增加,２４ｈ内排泄率     

恩诺沙星混悬液在猪体内残留消除规律研究

采用高效液相色谱法研究恩诺沙星(口服)混悬液在猪体内各组织中的残留消除规律.恩诺沙星(口服)混悬液,按每头猪10 mg/kg体重的剂量灌服给药,连续使用3 d之后,宰杀猪,取组织.组织样品经磷酸盐缓冲液提取,C18固相萃取柱净化,过膜,用流动相0.05 mol/L磷酸溶液/三乙胺一乙腈(82+18)溶解,微孔过滤,进行...     

恩诺沙星混悬液在猪体内的药动学及生物利用度

本文比较了恩诺沙星混悬液和恩诺沙星溶液在猪体内的药动学特征和生物利用度。选用 7头健康猪按拉丁方设计进行静注、肌注恩诺沙星溶液和肌注恩诺沙星混悬液在猪体内的药物动力学研究。 3种给药方法的剂量均为 10mg/kg。猪静注给药的药时数据符合二室开放模型 ,主要药动学参数为 :t1/ 2α0 6 4± 0 15h ,t1/ 2 β9 0 6± 2 47h ,Vd(area) 4 40± 0 88L/kg ,ClB0 35± 0 0 6L·kg-1·h-1,AUC2 9 85± 4 11L·kg-1·h。猪肌注恩诺沙星溶液和恩诺沙星混悬液的药时数据符合一级吸收一室模型 ,其主要药动学参数分别为t1/ 2ka0 2 4± 0 10h和 1 2 5± 1 0 9h(P <0 0 5 ) ;t1/ 2ke8 90± 2 0 2h和 18 95± 4 5 5h(P <0 0 1) ;Tmax1 2 5± 0 41h和 5 14± 2 95h(P <0 0 1) ;Cmax1 5 4± 0 2 5 μg/ml和 0 87± 0 2 1μg/ml;AUC2 1 49± 4 94mg·L-1·h和 2 8 97± 10 80mg·L-1·h ;F72 0 %±17 4%和 97 7%± 35 0 %。比较肌注恩诺沙星混悬液和恩诺沙星溶液的主要药动学参数 ,二者有显著差异 ,前者的t1/ 2ka、Tmax、t1/ 2ke和Cmax分别为后者的 5 2、4 1、2 1和 0 6倍。这些差异说明恩诺沙星混悬液肌注后吸收缓慢 ,消除半衰期延长 ,临床应用 48h给药 1次仍能维持对常见病原菌的有效血药     

Pharmacokinetics of enrofloxacin after oral,intramuscular and bath administration in crucian carp (Carassius auratus gibelio)

The pharmacokinetics of enrofloxacin (ENR) was studied in crucian carp (Carassius auratus gibelio) after single administration by intramuscular (IM) injection and oral gavage (PO) at a dose of 10 mg/kg body weight and by 5 mg/L bath for 5 hr at 25°C. The plasma concentrations of ENR and ciprofloxacin (CIP) were determined by HPLC. Pharmacokinetic parameters were calculated based on mean ENR or CIP concentrations using WinNonlin 6.1 software. After IM, PO and bath administration, the maximum plasma concentration (C_max) of 2.29, 3.24 and 0.36 μg/ml was obtained at 4.08, 0.68 and 0 hr, respectively; the elimination half‐life (T_1/2β) was 80.95, 62.17 and 61.15 hr, respectively; the area under the concentration–time curve (AUC) values were 223.46, 162.72 and 14.91 μg hr/ml, respectively. CIP, an active metabolite of enrofloxacin, was detected and measured after all methods of drug administration except bath. It is possible and practical to obtain therapeutic blood concentrations of enrofloxacin in the crucian carp using IM, PO and bath immersion administration.     

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in freshwater crocodiles (Crocodylus siamensis) after intravenous and intramuscular administration

To the best of the authors’ knowledge, pharmacokinetic information to establish suitable therapeutic plans for freshwater crocodiles is limited. Therefore, the purpose of this study was to clarify the pharmacokinetic characteristics of enrofloxacin (ENR) in freshwater crocodiles, Crocodylus siamensis, following single intravenous and intramuscular administration at a dosage of 5 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 168 hr. The plasma concentrations of ENR and its metabolite ciprofloxacin (CIP) were measured by liquid chromatography tandem–mass spectrometry. The concentrations of ENR and CIP in the plasma were quantified up to 144 hr after both the administrations. The half-life was long (43–44 hr) and similar after both administrations. The absolute i.m. bioavailability was 82.65% and the binding percentage of ENR to plasma protein ranged from 9% to 18% with an average of 10.6%. Percentage of CIP (plasma concentrations) was 15.9% and 19.9% after i.v. and i.m. administration, respectively. Based on the pharmacokinetic data, susceptibility break point and PK-PD indexes, i.m. single administration of ENR at a dosage of 5 mg/kg b.w. might be appropriate for treatment of susceptible bacteria (MIC > 1 μg/mL) in freshwater crocodiles, C. siamensis.     

Pharmacokinetics and tissue distribution of enrofloxacin after single intramuscular injection in Pacific white shrimp

The pharmacokinetic properties and tissue distribution of enrofloxacin (EF) were investigated after single intramuscular (i.m.) dose of 10 mg/kg body weight (b.w.) in Pacific white shrimp at 22 to 25°C. EF and its metabolite ciprofloxacin (CF) were determined by high‐performance liquid chromatography. After i.m. administration, EF was absorbed quickly, and the peak of EF concentration (C_max) reached at first time point in hemolymph. The volume of distribution V_d(area) of EF was 3.84 L/kg, indicating that the distribution of EF was good. The area under the concentration–time curve (AUC) of EF was 90.1 and 274.2 μg hr/ml in muscle and hepatopancreas, respectively, which was higher than 75.8 μg hr/ml in hemolymph. The EF elimination was slow in muscle and hepatopancreas with the half‐life (T_1/2β) of 52.3 and 75.8 hr, respectively. CF, the mainly metabolite of EF, was detected in hemolymph, muscle and hepatopancreas. The C_max was 0.030, 0.013 and 0.218 μg/ml, respectively. Based on a minimum inhibitory concentration (MIC) of 0.006–0.032 μg/ml for susceptible strains, EF i.m. injected at a dose 10 mg/kg could be efficacious against common pathogenic bacteria of Pacific white shrimp.     

Pharmacokinetics and tissue residues of enrofloxacin in the largemouth bass (Micropterus salmoides) after oral administration

The study was carried out to evaluate the pharmacokinetic disposition of enrofloxacin (ENF) with a single dose of 20 mg/kg after oral administration in largemouth bass (Micropterus salmoides) at 28°C. The concentrations of ENF and of its metabolite ciprofloxacin (CIP) in plasma, liver, and muscle plus skin in natural proportions were determined using HPLC. The concentration–time data for ENF in plasma were best described by a two-compartment open model. After oral administration, the maximum ENF concentration (C_max) of 10.99 μg/ml was obtained at 0.60 hr. The absorption half-life (T_1/2Ka) of ENF was calculated to be 0.07 hr whereas the elimination half-life (T_1/2β) of the drug was 90.79 hr. The estimates of area under the plasma concentration–time curve (AUC) and apparent volume of distribution (Vd/F) were 1,185.73 μg hr/ml and 2.21 L/kg, respectively. ENF residues were slowly depleted from the liver and muscle plus skin of largemouth bass with the T_1/2β of 124.73 and 115.14 hr, respectively. Very low levels of ciprofloxacin were detected in the plasma and tissues. A withdrawal time of 24 days was necessary to ensure that the residues of ENF + CIP in muscle plus skin were less than the maximal residue limit (MRL) of 100 μg/kg established by the European Union.     

Renal excretion of digoxin in swine and goats.

In experiments on swine and goats the renal excretion of digoxin was examined, and it was found that the renal clearance of non-protein-bound digoxin in swine was lower than creatinine clearance which expresses filtration clearance. Correlation analysis showed that the renal clearance of digoxin in swine was not significantly influenced by the concentration of non-protein-bound digoxin in plasma and the pH of the urine, while there was a significant positive correlation between the clearance and the urine flow rate (Table 4). On the other hand, the renal clearance of digoxin in goats was significantly influenced by the concentration of non-proteinbound digoxin in plasma and by urine pH (Table 4). From these results it is concluded that glomerular filtration and back-diffusion are involved in the renal handling of digoxin in both swine and goats. In addition active tubular secretion is also involved in the renal excretion of digoxin in goats.     

Disposition kinetics and urinary excretion of ciprofloxacin in goats following single intravenous administration

We evaluated the pharmacokinetics of ciprofloxacin in serum (n = 6) and urine (n = 4) in goats following a single intravenous administration of 4 mg/kg body weight. The serum concentration-time curves of ciprofloxacin were best fitted by a two-compartment open model. The drug was detected in goat serum up to 12 h. The elimination rate constant (β) and elimination half-life (t_1/2β) were 0.446 ± 0.04 h^-1 and 1.630 ± 0.17 h, respectively. The apparent volume of distribution at steady state (Vd_ss) was 2.012 ± 0.37 l/kg and the total body clearance (Cl_B) was 16.27 ± 1.87 ml/min/kg. Urinary recovery of ciprofloxacin was 29.70% ± 10.34% of the administered dose within 36 h post administration. In vitro serum protein binding was 41% ± 13.10%. Thus, a single daily intravenous dose of 4 mg/kg is sufficient to maintain effective levels in serum and for 36 h in urine, allowing treatment of systemic, Gram-negative bacterial infections and urinary tract infections by most pathogens.