恩诺沙星、恩诺沙星钠和盐酸恩诺沙星在鸡体内的比较药动学

36只黄羽肉鸡,随机均分为3组,每组12只,分别进行恩诺沙星、恩诺沙星钠和盐酸恩诺沙星的药动学试验,高致液相色谱法测定鸡只血浆中恩诺沙星浓度,MCPKP程序处理药-时数据。恩诺沙星、恩诺沙星钠和盐酸恩诺沙星溶液经内服给药后在鸡体内最佳药动学模型为一级吸收一室模型,峰浓度高（峰浓度分别为2．39、2．04和2．37μg／mL）,吸收快（吸收半衰期t1/2Ka分别为1．15h、0．76h和1．55h）,消除缓慢（消除半衰期t1/2K分别为8．39h、12．19h和10．95h）。以恩诺沙星做对照,恩诺沙星钠和盐酸恩诺沙星内服给药后吸收完全,其相对生物利用度高,分别为103．2％和126．8％。恩诺沙星钠和盐酸恩诺沙星内服给药后主要药动学参数与恩诺沙星给药后的药动学参数相比均无显著性差异．     

恩诺沙星及其代谢物环丙沙星在犬体内的药动学研究

10只健康家犬,按每千克体重2.5mg单剂量静脉注射恩诺沙星,进行恩诺沙星及其代谢产物环丙沙星在家犬体内的药动学研究。反相HPLC法测定血浆中的恩诺沙星及其代谢产物环丙沙星的浓度,所得血药浓度-时间数据用3P97计算机程序分析处理。结果表明:家犬静脉注射恩诺沙星后,恩诺沙星的药时数据符合二室模型,主要药动学参数:t1/2a为0.32h、t1/2β为3.22h、Vc为1.88L·kg-1、CL为1.74L·kg-1·h-1、AUC为1.88μg·mL-1·h,代谢物环丙沙星的主要动力学参数为:AUC为1.72μg·mL-1·h、MRT为7.72h。恩诺沙星在家犬体内的动力学特征是分布迅速、广泛,其消除跟代谢物环丙沙星一样表现迅速。     

乳酸恩诺沙星可溶性粉在鸡体内的药动学研究

24只苏禽黄羽肉鸡随机分成2组,分别按10 mg/kg体重剂量静注和内服乳酸恩诺沙星。测定乳酸恩诺沙星在鸡体内的药动学参数和生物利用度。恩诺沙星血药浓度数据用3p87计算机软件处理。静注乳酸恩诺沙星后的血药浓度-时间数据符合二室开放模型,主要动力学参数:t1/2α(0.45±0.16)h,t1/2β(7.02±1.42)h,CL(s)(0.38±0.10)L/kg/h,AUC(23.69±5.56)(mg/L)×h。内服乳酸恩诺沙星的血药浓度时间数据,符合有吸收因素二室模型,主要动力学参数:t1/2ka(0.60±0.01)h,t1/2ke(8.25±1.73)h,tpeak(2.44±0.17)h,Cmax(1.44±0.30)mg/L,AUC(20.74±3.80)(mg/L)×h,F 87.54%。结果表明,乳酸恩诺沙星可溶性粉在鸡体内具有吸收快、分布广、消除较慢以及内服生物利用度高的药动学特征。     

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。     

长效恩诺沙星注射液体外释药实验及在山羊体内的药动学研究

本文比较了恩诺沙星注射剂和长效恩诺沙星注射液体外释药动力学和在山羊体内的药动学特征。采用紫外分光光度法测定了体外释放率;选用8头健康山羊进行肌注长效恩诺沙星注射液和恩诺沙星注射液的药物动力学研究,以反相高效液相色谱法测定血浆中恩诺沙星的浓度。恩诺沙星普通注射液1h体外累计释药百分率达83 22%,而长效恩诺沙星注射液10h释药仅80 56%。肌注长效恩诺沙星注射液和恩诺沙星注射液的药时数据符合一级吸收一室模型,主要药动学参数分别为:T1/2Ka1 76±0 12hand0 34±0 04h(P<0 01);T2/1Ke7 50±0 39hand1 15±0 10h(P<0 01);Tmax4 81±0 26hand0 85±0 09h(P<0 01)。两者的体外释药率和药代动力学参数有显著差异,前者的吸收半衰期、达峰时间及消除半衰期分别为后者的5 2、5 7和6 5倍。说明恩诺沙星注射液肌注后吸收缓慢、消除半衰期延长,具有缓释特征,能起到长效的作用。     

恩诺沙星纳米混悬注射剂的制备及在猪体内药动学研究

采用高压均质法制备恩诺沙星纳米混悬注射剂并对其制备工艺和质量进行考察、评价;采用高效液相色谱法测定猪血浆中恩诺沙星的浓度,以拜有利注射剂为参照考察恩诺沙星纳米混悬注射剂在猪体内的药动学。结果显示:制备的恩诺沙星纳米混悬注射剂,恩诺沙星的含量为97.9%,平均粒径为(613.21±5.78)nm、PDI(0.22±0.02)、Zeta电位为-2.02mV。恩诺沙星纳米混悬注射剂和拜有利注射剂在猪体内的达峰浓度(Cmax)分别为(0.32±0.12)、(0.67±0.09)mg/L,达峰时间(Tmax)分别为(2.88±0.96)、(0.79±0.26)h,消除半衰期(t1/2ke)分别为(5.99±1.37)、(4.49±1.25)h,AUClast分别为每小时(4.63±1.30)、(4.40±0.45)mg/L,MRTlast分别为(9.59±2.34)、(5.41±1.10)h;与拜有利注射剂相比,恩诺沙星纳米混悬注射剂相对生物利用度为105.2%。结论:高压均质法制备的恩诺沙星纳米混悬注射剂操作简单、不易沉降、再分散性好,理化性质较稳定;与拜有利注射剂相比其Tmax、t1/2k明显增加(P<0.01),MRT显著延长(P<0.01)表明恩诺沙星纳米混悬注射剂具有明显缓释作用且消除缓慢。     

恩诺沙星微囊在猪体内的药动学及生物利用度研究

为了比较恩诺沙星微囊和原粉在猪体内的药动学特征及生物利用度,试验采用高效液相色谱法(HPLC),将10头健康猪分2组采用正交试验,经灌胃给药后采血、甲醇提取和HPLC分析,所得药时数据用MCPKP计算机程序处理。恩诺沙星微囊和原粉经口服给药后在猪体内的药时数据均符合一级吸收一室模型,主要药动学参数分别为:t1/2Ka1.73 h±0.93 h和0.36 h±0.31 h(P0.01);Tmax5.69 h±1.68 h和2.04 h±1.06 h(P0.01);t1/2Ke16.53 h±5.23 h和10.17 h±1.87 h(P0.01);Cmax1.71μg/mL±0.47μg/mL和2.51μg/mL±0.45μg/mL(P0.01);AUC为每小时51.98μg/mL±16.08μg/mL和40.58μg/mL±6.40μg/mL;微囊的相对生物利用度为128%。说明恩诺沙星微囊口服给药吸收较慢但完全,达峰时间较长,消除缓慢。     

两种氟苯尼考粉剂在肉鸡体内的药动学比较

健康黄羽肉鸡(公母各半)20只随机分为A、B 2组,分别单剂量灌服19.91%氟苯尼考粉(受试品)和10%氟苯尼考粉(对照品),给药量均为15 mg/kg,进行药动学比较研究。给药后按预定时间采集血样,采用高效液相色谱法(HPLC)法测定血浆中药物含量。实测血药浓度-时间数据,采用Win Nonlin 5.2.1药动学分析软件处理。结果显示:A组平均消除半衰期(T_(1/2β))约为9.158 h,达峰时间(T~(max))和峰值浓度(C~(max))分别为0.600 h和5.786μg/m L,平均曲线下面积(AUC)为26.474 h·μg/m L,平均滞留时间(MRT)4.357 h;B组平均T_(1/2β)约为7.513 h,T~(max)和C~(max)分别为1.900 h和5.106 mg/L,AUC为25.749 h·μg/m L,MRT 5.695 h;相对生物利用度约为93.979%。结果表明,19.91%氟苯尼考粉T~(max)比10%氟苯尼考粉提前(P0.01),其他药动学参数无明显差异(P0.05)。     

两种氟苯尼考注射液在鸡体内比较药动学研究

为比较两种氟苯尼考注射液的药物代谢动力学,本研究选择30只健康鸡随机分为两组,分别单剂量20 mg/kg bw肌内注射受试制剂和参比制剂,于给药后0.167、0.33、0.5、0.75、1、1.5、2、4、6、8、12、24、48 h翼下静脉采集血样。用超高效液相色谱法（UPLC-UV）测定血浆中氟苯尼考的含量,并用WinNonlin 8.1非房室模型计算主要药代动力学参数。结果显示,受试制剂和参比制剂的t1/2分别为（3.39±2.65）和（4.47±3.14）h,Tmax分别为（0.66±0.30）和（0.77±0.30）h,Cmax分别为（7.06±2.35）和（8.24±4.54）μg/mL,AUC0→t分别为（19.05±5.79）和（21.76±6.71）（μg/mL）h,AUC0→∞分别为（20.11±6.36）和（23.04±6.91）（μg/mL）h,MRT分别为（3.25±1.25）和（3.55±0.96）h,相对生物利用度为87.55%。结果表明,虽然二者主要药动学参数无显著性差异（p＞0.05）,但受试制剂相对生物利用度较低。     

两种头孢噻呋注射液在猪体内的比较药动学研究

研究了两种头孢噻呋注射液给猪肌注后的比较药物动力学特征。选用12头健康猪随机分为两组,每组6头,分别肌注上海公谊兽药厂生产的长效盐酸头孢噻呋注射液和美国辉瑞生产的盐酸头孢噻呋注射液（速解灵注射液）,每头5mg／kg。采用超高效液相色谱法测定猪血浆中头孢噻呋的的药物浓度,用Winnonlin5．2药动学分析软件非房室模型处理药时数据,模型200处理肌注给药后的药代动力学参数。结果表明：健康猪肌注两种注射液后,参数MRT、Cmax、tmax统计差异极显著（P〈0．01）,长效盐酸头孢噻呋注射液单剂量肌注给药较速解灵注射液吸收慢,达峰时间显著延迟,达峰浓度显著降低,平均驻留时间显著延长;参数AUC、Kel、t1/2允统计无显著性差异（P〉0．05）,长效盐酸头孢噻呋注射液的相对生物利用度为98．41％,与速解灵注射液的生物利用度相当。本研究可为头孢噻呋注射液的临床合理用药提供参考。     

Pharmacokinetics of enrofloxacin in allogynogenetic silver crucian carp, Carassius auratus gibelio

The pharmacokinetics of enrofloxacin (EF) was investigated after single intravenous (i.v.) and oral (p.o.) administration of 10 mg/kg body weight (b.w.) in 300 healthy allogynogenetic silver crucian carp at 24-26°C. The plasma concentrations of EF and its metabolite ciprofloxacin (CF) were determined by high-performance liquid chromatography. After i.v. administration, the plasma concentration-time data were described by an open two-compartment model. The elimination half-life (T(1/2β)), area under the concentration-time curve (AUC) and total body clearance of EF were 63.5 h, 239.6 μg·h/mL and 0.04 L/h/kg, respectively. Following p.o. administration, the plasma concentration-time data showed a double peak-shaped curve, indicating the possibility of enterohepatic recirculation of EF in allogynogenetic silver crucian carp. The maximum plasma concentration (C(max)), T(1/2β) and AUC of EF were 4.5 μg/mL, 62.7 h and 205.9 μg·h/mL, respectively. Absorption of EF was very good with a bioavailability (F) of 86%, which could be correlated with the unique structure of the alimentary canal in allogynogenetic silver crucian. CF, an active metabolite of EF, was not detected in this study.     

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 difloxacin in olive flounder Paralichthys olivaceus at two water temperatures

In this study, the pharmacokinetics profiles of difloxacin in the olive flounder (Paralichthys olivaceus) were investigated following intravenous and oral administration (10 mg/kg BW) at 14 and 22 °C water temperatures. Plasma and tissue samples (muscle, liver, and kidney) were analyzed using an HPLC method. The results showed that the plasma concentration–time data for difloxacin were described commendably by two‐compartment open model at the two water temperatures. The absorption half‐life (t_1/2ka) of difloxacin after oral administration were 2.08 and 1.10 h at 14 and 22 °C, respectively; whereas the elimination half‐life (t_1/2β) was 4.41 and 2.38 h, respectively. The muscle concentration of 1.35 ± 0.19 μg/g was observed at 9 h at 14 °C, and 2.11 ± 0.33 μg/g at 6 h at 22 °C, respectively. For liver, the peak concentration of difloxacin 2.43 ± 0.30 μg/g occurred at 6 h at 14 °C, which was lower than the 3.34 ± 0.24 μg/g peak that occurred at 4 h at 22 °C. The calculated bioavailability of difloxacin was 68.07% at 22 °C, which was higher than the 53.43% calculated for 14 °C. After intravenous administration, the t_1/2β were 4.79 and 2.81 h at 14 and 22 °C, respectively. The results indicate that the peak concentrations in muscle and liver at 14 °C are approximately half of those achieved at 22 °C. However, the C_max in kidney at 14 and 22 °C were similar. The V_d values were 1.20 and 1.75 L/kg at 14 and 22 °C, respectively. These data indicated that both temperature and drug administration had significant effects on the elimination of difloxacin, and lower temperature or oral administration resulted in lower elimination.     

Pharmacokinetics of florfenicol and its metabolite florfenicol amine in crucian carp (Carassius auratus) at three temperatures after one single intramuscular injection

The pharmacokinetic profiles of florfenicol (FF) or florfenicol amine (FFA) in crucian carp were compared at different water temperatures after single intramuscular administration of FF at 10 mg/kg bodyweight. The concentrations of FF and FFA were determined by a high‐performance liquid chromatography method, and then, the concentration versus time data were subjected to compartmental analysis using a one‐compartment open model. At the water temperatures of 10, 20, and 25°C, the peak concentrations (C_maxs) of FF were 2.28, 2.29, and 2.34 μg/ml, respectively, while those of FFA were 0.42, 0.71, and 0.82 μg/ml, respectively. And the absorption half‐life (t_1/2ka) of FF was 0.21, 0.19, and 0.21 hr, while the elimination half‐life (t_1/2kel) was 31.66, 24.77, and 21.48 hr, respectively. For FFA, the formation half‐life (t_1/2kf) was 3.85, 8.97, and 12.43 hr, while the t_1/2kel was 58.34, 30.27, and 21.22 hr, respectively. The results presented here demonstrated that the water temperature had effects on the elimination of both FF and FFA and the formation of FFA. Based on the T > MIC values calculated here, to treat the infections of bacterial with MIC value ≤ 0.5 μg/ml, FF intramuscularly given at 10 mg/kg bodyweight with a 72‐hr interval is sufficient at the water temperature of 10°C, while the intervals of 60 and 48 hr were needed at 20 and 25°C, respectively. But to treat bacterial with higher MIC values, more FF or FF at 10 mg/kg BW but with shorter intervals should be intramuscularly given to the infected fish.     

Pharmacokinetics of enrofloxacin in turkeys

The pharmacokinetics of enrofloxacin (EFL) and its active metabolite ciprofloxacin (CIP) was investigated in 7-8 month old turkeys (6 birds per sex). EFL was administered intravenously (i.v.) and orally (p.o.) at a dose 10 mg kg(-1) body weight. Blood was taken prior to and at 0.17, 0.33, 0.5, 1, 2, 3, 4, 6, 8, 10 and 24 h following drug administration. The concentrations of EFL and CIP in blood serum were determined by high-performance liquid chromatography (HPLC). Serum concentrations versus time were analysed by a noncompartmental analysis. The elimination half-live and the mean residence time of EFL after i.v. injection for the serum were after oral administration 6.64+/-0.90 h, 8.96+/-1.18 h and 6.92+/-0.97 h, 11.91+/-1.87 h, respectively. After single p.o. administration, EFL was absorbed slowly (MAT=2.76+/-0.48 h) with time to reach maximum serum concentrations of 6.33+/-2.54 h. Maximum serum concentrations was 1.23+/-0.30 microg mL(-1). Oral bioavailability for for EFL after oral administration was found to be 69.20+/-1.49%. The ratios C(max)/MIC and AUC(0 --> 24)/MIC were respectively from 161.23+/-5.9 h to 12.90+/-0.5 h for the pharmacodynamic predictor C(max)/MIC, and from 2153.44+/-66.6 h to 137.82+/-4.27 h for AUC(0 --> 24)/MIC, for the different clinically significant microorganisms, whose values for MIC varies from 0.008 microg L(-1) to 0.125 microg mL(-1).     

恩诺沙星在鹅体内的药代动力学研究

本文对恩诺沙星在鹅体内的药动学特征进行了研究,36只鹅随机分为2组,A组静脉注射恩诺沙星溶液;B组口服恩诺沙星溶液,给药剂量均为10mg/kg体重。数据采用DAS2.0进行分析。试验结果显示,静脉注射组多项药动学参数与口服组相比存在较显著差异,静脉注射组AUC约为口服组的1.3倍,在其体内清除率仅为口服组的3/5,但在体内消除却较快,平均驻留时间仅为口服组的7/10,结合恩诺沙星对常见敏感菌的MIC参数考虑,可以认为,口服10mg/kg剂量可以满足临床养殖中抗敏感细菌感染的要求。     

Pharmacokinetics of orbifloxacin in crucian carp (Carassius auratus) after intravenous and intramuscular administration

The pharmacokinetics of orbifloxacin was studied after a single dose (7.5 mg/kg) of intravenous or intramuscular administration to crucian carp (Carassius auratus ) reared in freshwater at 25°C. Plasma samples were collected from six fish per sampling point. Orbifloxacin concentrations were determined by high‐performance liquid chromatography with a 0.02 μg/ml limit of detection, then were subjected to noncompartmental analysis. After intravenous injection, initial concentration of 5.83 μg/ml, apparent elimination rate constant (λ_z) of 0.039 hr^?1, apparent elimination half‐life (T_1/2λz) of 17.90 hr, systemic total body clearance (Cl) of 75.47 ml hr^?1 kg^?1, volume of distribution (Vz) of 1,948.76 ml/kg, and volume of distribution at steady‐state (Vss) of 1,863.97 ml/kg were determined, respectively. While after intramuscular administration, the λ_z, T _1/2λz, mean absorption time (MAT ), absorption half‐life (T _1/2ka), and bioavailability were determined as 0.027 hr^?1, 25.69, 10.26, 7.11 hr, and 96.46%, respectively, while the peak concentration was observed as 3.11 ± 0.06 μg/ml at 2.0 hr. It was shown that orbifloxacin was completely but relatively slowly absorbed, extensively distributed, and slowly eliminated in crucian carp, and an orbifloxacin dosage of 10 mg/kg administered intravenously or intramuscularly would be expected to successfully treat crucian carp infected by strains with MIC values ≤0.5 μg/ml.     

Comparative pharmacokinetics of enrofloxacin in healthy and Aeromonas hydrophila‐infected crucian carp (Carassius auratus gibelio)

The comparative pharmacokinetics of enrofloxacin (ENR) and its metabolite ciprofloxacin (CIP) were investigated in healthy and Aeromonas hydrophila‐infected crucian carp after a single oral (p.o.) administration at a dose of 10 mg/kg at 25 °C. The plasma concentrations of ENR and of CIP were determined by HPLC. Pharmacokinetic parameters were calculated based on mean ENR concentrations by noncompartmental modeling. In healthy fish, the elimination half‐life (T_1/2λz), maximum plasma concentration (C_max), time to peak (T_max), and area under the concentration–time curve (AUC) values were 64.66 h, 3.55 μg/mL, 0.5 h, and 163.04 μg·h/mL, respectively. In infected carp, by contrast, the corresponding values were 73.70 h, 2.66 μg/mL, 0.75 h, and 137.43 μg·h/mL, and the absorption and elimination of ENR were slower following oral administration. Very low levels of CIP were detected, which indicates a low extent of deethylation of ENR in crucian carp.     

Pharmacokinetics of enrofloxacin in neonatal kittens

OBJECTIVE: To determine the pharmacokinetics of enrofloxacin in neonatal kittens and compare the pharmacokinetics of enrofloxacin in young and adult cats. ANIMALS: 7 adult cats and 111 kittens (2 to 8 weeks old). PROCEDURE: A single dose of 5 mg of enrofloxacin/kg was administered to adults (i.v.) and kittens (i.v., s.c., or p.o.). Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined. RESULTS: The half-life of enrofloxacin administered i.v. in 2-, 6-, and 8-week-old kittens was significantly shorter and its elimination rate significantly greater than that detected in adults. The apparent volumes of distribution were lower at 2 to 4 weeks and greater at 6 to 8 weeks. This resulted in lower peak plasma concentration (Cmax) at 6 to 8 weeks; however, initial plasma concentration was within the therapeutic range after i.v. administration at all ages. Compared with i.v. administration, s.c. injection of enrofloxacin in 2-week-old kittens resulted in similar Cmax, half-life, clearance, and area under the curve values. Enrofloxacin administered via s.c. injection was well absorbed in 6- and 8-week-old kittens, but greater clearance and apparent volume of distribution resulted in lower plasma concentrations. Oral administration of enrofloxacin resulted in poor bioavailability. CONCLUSIONS AND CLINICAL RELEVANCE: In neonatal kittens, i.v. and s.c. administration of enrofloxacin provided an effective route of administration. Oral administration of enrofloxacin in kittens did not result in therapeutic drug concentrations. Doses may need to be increased to achieve therapeutic drug concentrations in 6- to 8-week-old kittens.