甲氧苄啶与中药复方联用抗菌增效作用的研究

探索甲氧苄啶对中药复方体外抗菌增效的最优添加剂量.根据传统中兽医理论,自拟中药复方由黄芩、板蓝根、蒲公英和连翘按1∶1∶2∶1比例组成.采用平板计数的方法,测定了甲氧苄啶与中药复方联用作用于金黄色葡萄球菌、大肠杆菌和沙门氏菌1、2、4和8h后的细菌数,计算杀菌率,并用最小二乘法对杀菌率进行拟合,得出甲氧苄啶的最优添加剂...     

HPLC法测定复方替米考星颗粒中有效成份含量

采用HPLC法同时测定了复方替米考星颗粒中替米考星、磺胺二甲氧嘧啶及甲氧苄啶的含量。色谱柱为Eclipse XCB-C18(250 mm×4.6 mm,粒径5μm),流动相为磷酸二丁胺缓冲液-乙腈-四氢呋喃-水(25∶115∶55∶805),检测波长280 nm,流速1.0 mL/min。出峰顺序为甲氧苄啶、磺胺二甲氧嘧啶、替米考星反式结构、替米考星顺式结构,理论塔板数分别为7963、15714、3282、8701。两峰之间的分离度分别为24.29、3.92、2.91;拖尾因子分别为0.92、0.90、0.97、0.94。替米考星、磺胺二甲氧嘧啶、甲氧苄啶的浓度线性范围分别是6.25～125μg/mL(R2=0.996),3.125～62.5μg/mL(R2=0.996),0.625～12.5μg/mL(R2=0.999);平均回收率分别为99.17%、99.06%和99.39%;RSD分别为0.8%、0.9%和0.9%。该法快速、灵敏、准确,适用于同时测定复方替米考星颗粒中三种成份的含量。     

高效液相色谱同时检测鱼肉组织中4种磺胺与甲氧苄啶的残留量

建立了同时测定鱼肉组织中4种磺胺(磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲基嘧啶、磺胺甲恶唑)和甲氧苄啶残留量的高效液相色谱法.鱼肉组织用乙腈提取后经乙腈饱和的正己烷去脂,过HLB柱净化,甲醇洗脱,减压浓缩蒸干,流动相(乙腈+1%乙酸,体积比为10∶90)定容,用带DAD检测器的高效液相色谱仪在272 nm波长下检测,流动相采用梯度洗脱.结果显示:4种磺胺和甲氧苄啶分别在0025～10 μg·mL-1和005～20 μg·mL-1范围内呈良好线性关系,相关系数(r)为0999;4种磺胺和甲氧苄啶分别在002、010和020 mg·kg-1和004、020和040mg·kg-1 3个浓度水平下的添加回收率为752%～979%,变异系数为28%～100%(n＝6);根据3倍信噪比计算,磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲基嘧啶、磺胺甲恶唑和甲氧苄啶的最低检测限分别为0006、0007、0008、0008和0019mg·kg-1.     

Validating an empiric sulfadiazine–trimethoprim dosage regimen for treatment of Escherichia coli and Staphylococcus delphini infections in mink (Neovison vison)

Antimicrobial agents are used extensively off‐label in mink, as almost no agents are registered for this animal species. Pharmacokinetic (PK) and pharmacodynamic (PD) data are required to determine antimicrobial dosages specifically targeting mink bacterial pathogens. The aims of this study were to assess, in a PKPD framework, the empirical dosage regimen for a combination of trimethoprim (TMP) and sulfadiazine (SDZ) in mink, and secondarily to produce data for future setting of clinical breakpoints. TMP and SDZ PK parameters were obtained experimentally in 22 minks following IV or oral administration of TMP/SDZ (30 mg/kg, i.e. 5 mg/kg TMP and 25 mg/kg SDZ). fAUC/MIC with a target value of 24 hr was selected as the PKPD index predictive of TMP/SDZ efficacy. Using a modeling approach, PKPD cutoffs for TMP and SDZ were determined as 0.062 and 16 mg/L, respectively. By incorporating an anticipated potentiation effect of SDZ on TMP against Escherichia coli and Staphylococcus delphini, the PKPD cutoff of TMP was revised to 0.312 mg/L, which is above the tentative epidemiological cutoffs (TECOFF) for these species. The current empirical TMP/SDZ dosage regimen (30 mg/kg, PO, once daily) therefore appears adequate for treatment of wild‐type E. coli and S. delphini infections in mink.     

UHPLC-Q/TOF MS结合HPLC-DAD定性和定量分析硫酸黏菌素可溶性粉中的未知添加物

定性和定量分析一批兽药硫酸黏菌素可溶性粉中的未知添加物。照《中国兽药典》2010年版一部对该批检品用微生物检定法进行含量测定时,发现该样品的抑菌圈为虚圈,用薄层色谱鉴别该样品,未显示与标准品溶液一致的主斑点,怀疑该样品中有处方外非法添加物。采用超高效液相色谱-四级杆-飞行时间质谱(UHPLC-Q/TOF MS)对该样品进行筛查,发现疑似添加物,并使用液相色谱-二极管阵列检测(HPLC-DAD)法进行了双重确证和含量测定。该样品中非法添加物确证为磺胺氯达嗪和甲氧苄啶,添加量分别为58.5 mg/g和13.4 mg/g。本研究通过建立筛查方法为监管部门提供技术支撑,通过分析非法添加物的可能原因为打击兽药处方外非法添加提供了思路。     

Concentrations of trimethoprim and sulphadoxine in tissues from goats and a cow.

The concentration of trimethoprim and sulphadoxine in plasma and tissue from goats and a cow have been determined after a single intravenous injection. Furthermore, the concentration of the two drugs and their metabolites in plasma and tissues have been determined after continuous intravenous infusion for 2½–3 hrs. Trimethoprim was present in all tissues but brain at higher concentrations than in plasma while the concentration of sulphadoxine in the different tissues were lower than in plasma. The highest concentration of the 2 drugs and their metabolites was found in the kidney. The distribution pattern of trimethoprim and sulphadoxine was similar in cow and goats.     

Plasma and Tissue Levels of Trimethoprim in The Rainbow Trout,Salmo Gairdneri,After Absorption From Fresh and Salt Water

This is a comparative study of uptake of trimethoprim from 1) fresh water, 2) salt water after 7 days of adaption and 3) salt water without previous adaptation. The rate and extent of absorption were found to vary significantly. The salt water adapted group reached a plasma concentration of approx. 1 µg/ml after 10 h, the unadapted salt water group after 24 to 48 h and the fresh water group did not reach this concentration. The results are discussed in relation to the non-ionic diffusion theory and to the alterations taking place in euryhaline species of fish during adaptation to salt water.     

高效液相色谱法测定甲氧苄啶含量

建立甲氧苄啶含量高效液相色谱测定方法。采用Diamonsil C18色谱柱(200mm×4.6mm,5μm),以甲醇∶0.02mol/L磷酸二氢钾溶液(30∶70)为流动相,流速为1.0mL/min,柱温为25℃,检测波长为271nm。甲氧苄啶对照品浓度在10μg/mL～160μg/mL范围内与峰面积呈线性关系,线性回归方程A=0.389 2C-0.369 6,r=0.999 9(n=5);平均回收率为99.61%,RSD=0.41%(n=5)。高效液相色谱法快速、简便,专属性强,重现性好,准确度高,可用于甲氧苄啶原料含量的测定。     

A comparison of some of the pharmacokinetic parameters of three commercial sulphadiazine/trimethoprim combined preparations given orally to pigs

Three sulphadiazine/trimethoprim preparations were administered orally during feeding to pigs. Six male and six female pigs were used. Clinically important pharmacokinetic parameters of the two drugs in the three preparations were determined and compared.The plasma concentrations of sulphadiazine and trimethoprim increased rapidly in the pigs followed by a quite rapid decrease from 4 to 12 h after oral administration. The mean values of the absorption half-lives of sulphadiazine and trimethoprim were 0.9–1.6 h and 0.5–0.8 h, respectively. The corresponding values for the elimination half-lives of sulphadiazine and trimethoprim were 3.1–4.3 h and 3.4–6.0 h, respectively. There were no significant differences between the pharmacokinetic parameters of the two compounds in the three preparations with the exception of T_max for sulphadiazine and t_1/2 for trimethoprim. Comparative bioavailability calculations showed no statistically significant differences between sulphadiazine and trimethoprim in the three preparations.The weight increase of the pigs during the experimental period (mean = 37.3–64.9 kg) did not cause differences in the kinetics of the two drugs which could have consequences for the use of the three combined preparations in clinical practice.No unacceptable or antibacterial residues of sulphadiazine or trimethoprim were found in the kidneys of pigs slaughtered at 5, 7 and 10 days after administration.     

三甲氧苄氨嘧啶对养殖大菱鲆盾纤毛虫病治疗效果的研究

从感染纤毛虫的养殖大菱鲆上分离获得盾纤毛虫进行体外培养,通过药物抑制实验发现,三甲氧苄氨嘧啶(TMP)对盾纤毛虫的最小有效抑制浓度为25×10~(-6);TMP对大菱鲆的毒性实验表明,24小时半致死量为每千克鱼体内含药物量为0.35357 g,48小时半致死量为每千克鱼体内含药物量为0.33912 g,安全量为每千克鱼体内含药物量为0.09361 g;TMP对大菱鲆盾纤毛虫病的治疗实验结果显示,与对照组相比,注射药物或投喂药饵后,感染纤毛虫的大菱鲆成活率提高了50%～107.1%。