泰拉霉素国家对照品的标定研究

为了有效控制泰拉霉素原料及注射液的产品质量,研制了泰拉霉素国家对照品。采用精制后的泰拉霉素为原料进行本批对照品的研制,原料分装后进行质量检测及均匀性评价,并标定含量。采用红外分光光度法、费休氏水分测定法等对其进行理化分析,利用高效液相色谱法进行有关物质测定及均匀性检验,采用质量平衡法进行标准物质含量计算,并通过差示扫描量热法对质量平衡法的准确性进行验证。研制的泰拉霉素国家对照品的含量为98.3%,采用多种不同方法对本品进行定性与定量研究,确保了国家标准物质标定结果的准确性。本对照品可用于泰拉霉素原料及注射液的鉴别与含量测定,对于提高和保证兽药产品质量具有重要意义。     

匹莫苯丹对照品的定值研究

为了研制匹莫苯丹对照品,采用精制后的匹莫苯丹为原料,并进行质量评价。采用熔点法、红外分光光度法、液相色谱法对原料进行鉴别,采用质量平衡法定值,同时采用容量法和高效液相色谱法加以佐证。结果显示,以质量平衡法计算其含量为99.8%,容量法测定含量为99.7%,液相色谱外标法测定含量为99.6%,三种方法测定结果一致。本次研制的匹莫苯丹对照品可用于匹莫苯丹及其制剂的鉴别与含量测定。     

甲苯咪唑国家对照品的研制

为了研制甲苯咪唑国家对照品,采用精制后的甲苯咪唑为原料,并进行质量评价。采用紫外分光光度法、红外分光光度法对原料进行鉴别,采用质量平衡法定值,同时采用容量法和高效液相色谱法加以佐证。结果显示,紫外吸收图谱与标准规定一致、红外光吸收图谱与USP溯源对照品图谱一致;以质量平衡法计算其含量为99.8%,容量法测定含量为99.9%,液相色谱外标法测定含量为99.9%,三种方法测定结果一致。本次研制的甲苯咪唑对照品可用于甲苯咪唑及其制剂的鉴别与含量测定。     

乙酰氨基阿维菌素国家对照品的研制

以乙酰氨基阿维菌素为原料研制首批乙酰氨基阿维菌素国家对照品,并进行质量评价。采用高效液相色谱法和质谱法对原料进行结构确证,分装后的乙酰氨基阿维菌素对照品采用质量平衡法定值,同时采用高效液相色谱外标法加以佐证。结果显示,以质量平衡法计算乙酰氨基阿维菌素(B_1a+B_1b)含量为97.79%,液相色谱外标法测定含量为98.18%,两种方法测定结果基本一致。本次研制的乙酰氨基阿维菌素对照品可用于乙酰氨基阿维菌素及其制剂的鉴别与含量测定。     

加米霉素对照品标定方法的建立

建立了加米霉素对照品的标定方法。采用紫外光谱、红外光谱、核磁共振波谱、质谱和X射线单晶衍射进行结构确认,高效液相色谱法进行纯度检查,质量平衡法进行定量分析,并采用定量核磁技术对赋值结果进行验证。结果显示,加米霉素对照品原料纯度为99.9%;质量平衡法赋值结果为98.8%,定量核磁共振法验证结果为98.3%。加米霉素对照品原料定量赋值结果准确、可靠,能够用于加米霉素原料及制剂的鉴别和含量测定。     

饲料中硝态氮对燃烧法与凯氏法总氮含量测定结果的影响

为了确定硝态氮对饲料含氮量的杜马斯燃烧法测定值(Cn)和凯氏法测定值(Kn)的影响,对14种硝态氮含量较高的饲料原料,采用杜马斯燃烧法和凯氏法测定各样本中的含氮量,并以化学法测定硝态氮含量为对照进行分析。结果表明:14种样本含氮量的燃烧法测定值显著高于凯氏法测定值(P<0.01),虽然2种方法测定结果间高度相关(r=0.9960),但拟合曲线与Y=X存在显著差异(P<0.01),燃烧法与凯氏法测定值间差值(Cn-Kn)与饲料中硝态氮含量相关性低(R2=0.6036)。由此可得出,当饲料中含有大量硝态氮时,燃烧法测定值显著高于凯氏法测定值,但2种方法测定值差与硝态氮含量相关性低,因此硝态氮是造成饲料含氮量的燃烧法与凯氏法测定值间差异的原因之一,但不是惟一原因。     

白头翁对照提取物的制备及其在药材质量控制中的应用

为制备并标定白头翁对照提取物，探讨白头翁对照提取物代替单体对照品在中药质量控制中应用的科学性和可行性，本试验采用大孔吸附树脂法结合高速逆流色谱法制备白头翁对照提取物；采用高效液相色谱法，以白头翁皂苷H、白头翁皂苷B₄和常春藤皂苷C为指标对其进行含量标定；分别以已知含量的对照提取物和3个单体对照品为对照，通过高效液相色谱法测定32批白头翁药材中3个化学成分的含量，对照提取物法和对照品法测得的结果采用t检验法进行比较。结果显示，2种方法测定白头翁药材中白头翁皂苷H、白头翁皂苷B₄和常春藤皂苷C的含量，无显著性差异(P>0.05)。结果表明，白头翁对照提取物替代单体对照品用于白头翁药材质量控制的方法科学可行，为白头翁药材的质量评价提供了新的思路和方法。     

烯丙孕素对照品的研制及标定

研制了烯丙孕素对照品并对其进行标定。采用紫外光谱、红外光谱、核磁共振波谱、质谱和X射线单晶衍射进行结构确认,高效液相色谱法进行纯度检查,质量平衡法进行定量分析,并用核磁共振波谱法对赋值结果进行验证。结果显示,烯丙孕素对照品原料纯度为99.96%;质量平衡法赋值结果为99.92%,定量核磁共振法验证结果为99.60%。烯丙孕素工作对照品定量赋值结果准确、可靠,能够用于烯丙孕素原料及制剂的鉴别和含量测定。     

黄芩苷-β-环糊精包合物的制备与鉴定

本文描述了黄芩苷-β—环糊精包合物的制备和鉴定方法。用溶液—电动搅拌法制备黄芩苷—β-环糊精包合物，HPLC法测定其含量。黄芩苷—β—环糊精包合物与物理混合物的差示量热扫描(DSC)及x—射线衍射扫描图谱均有明显差异，证明黄芩苷与β-环糊精包合成功。     

霉菌毒素的不同检测方法在饲料生产中的应用探讨

霉菌毒素目前常用的检测方法有薄层层析法(TLC)、色谱法、质谱联用技术、免疫化学检测法等。各种检测方法的灵敏度、准确度、稳定性、检测环境、操作难易程度、设备和费用的局限应用领域有较大的差异。本实验室采用高效液相色谱(HPLC-MS/MS)、横向流动免疫技术(LFD)、酶联免疫吸附法(ELISA)三种方法测定玉米基质定值质控品A、B、C样品的呕吐毒素、黄曲霉毒素B1、玉米赤霉烯酮三种毒素的含量,评估空白样品和定值质控品的检测结果和回收率,根据临床应用,比较三种不同的霉菌毒素检测方法的优缺点。准确度评估结果显示:HPLC-MS/MS法ELISA法LFD法,但三种方法都有各自的优缺点,实际生产可以灵活选择使用。     

Comparison of febantel tablets and Vercom paste against gastrointestinal nematodes of dogs.

Thirty adult dogs with naturally acquired gastrointestinal nematode infections were assigned at random to ten replicates and treated daily for 3 days with either a combination febantel/praziquantel (Vercom) paste, febantel tablets or placebo tablets. Numbers of hookworm and whipworm eggs after treatment were reduced similarly for both drug formulations when compared with pretreatment egg counts, whereas these counts increased in the controls. Vercom paste reduced the hookworm egg count by 99.9% and the whipworm egg count by 99.6%. The febantel tablet decreased the hookworm egg count by 99.9% and the whipworm egg count by 100%. As determined at necropsy, the controlled test efficacy against adult hookworms and whipworms was similar for the Vercom paste and the febantel tablets. The controlled test efficacies of Vercom paste against Ancylostoma caninum, Ancylostoma braziliense, and Trichuris vulpis were, respectively, 99.7%, 100% and 95.8% and those of febantel tablets were 98.2%, 100% and 99.7%. These results indicate that the nematocidal efficacy of febantel against these nematodes remains unchanged in these two formulations. No adverse reactions to either febantel tablets or to Vercom paste were observed.     

The bioavailability of febantel in dehydrated camels

In the present study the bioavailability of febantel paste and febantel suspension was investigated in the fully hydrated and the dehydrated camel. The serum concentrations of febantel and its metabolites, fenbendazole, oxfendazole and fenbendazole sulfone were determined by high performance liquid chromatography following extraction with ether. The exposure to febantel and its metabolites in fully hydrated camels was significantly higher in camels dosed with febantel paste compared to febantel suspension, as measured by AUC and C _max· The AUC and C _max of fenbendazole and oxfendazole were significantly lower in dehydrated camels as compared to control camels dosed with febantel paste. The systemic availability of febantel suspension in control and dehydrated camels was very low and differences between dehydration and control phases were insignificant. The low systemic availability of febantel in camels dosed with febantel suspension may cause nematodes to become resistant to this anthelmintic. It is, thus, suggested to increase the dose of febantel paste in dehydrated camels in order to increase the exposure to febantel and its metabolites. The binding of febantel, fenbendazole, oxfendazole and fenbendazole sulfone to camels'serum proteins was over 85%. Oxfendazole was only about 70% bound. Dehydration of 10 days did not affect the binding of these benzimidazole derivatives to serum proteins.     

Comparative pharmacokinetics of febantel and its metabolites in sheep and cattle

The pharmacokinetics of febantel and its main metabolites were studied in cattle and sheep. Seven ewes and 4 heifers were given febantel orally in a single dose of 7.5 mg/kg, 25 mg/kg, or 45 mg/kg of body weight. Plasma concentrations vs time of febantel and individual metabolites were determined by high-performance liquid chromatography analysis. Intestinal absorption of febantel was faster and biotransformations were more active in sheep than in cattle.     

The influence of Ostertagia circumcincta and Trichostrongylus colubriformis infections on the pharmacokinetics of febantel in lambs

Plasma concentrations of febantel and its major metabolites fenbendazole, oxfendazole and oxfendazole sulphone were determined after oral administration of 7.5 mg/kg febantel in lambs before and 28 days after infection with 50 000 L₃ larvae of Ostertagia circumcincta or Trichostrongylus colubriformis. The febantel concentrations were always very low and only in a few samples higher than the detection limit. The mean decrease in AUC for the three metabolites for the infected sheep in comparison to the parasite naive sheep was 13.9%± 4.1% (mean± SEM) and 23.7%± 5.3% in the 0. circumcincta infected and the T. colubriformis infected lambs respectively. This reduction was only significant for the T. colubriformis infected group.
In order to determine a more complete pharmacokinetic profile, febantel was injected intravenously at a dose of 2.5 mg/kg in a further study.     

Determination of Pinoresinol Diglucoside in Eucommie ulmoides Immunoenhancement Liquids by RP-HPLC

The assay was aimed to determine the content of pinoresinol diglucoside (PDG) in Eucommie ulmoides immunoenhancement liquids. The chromatographic conditions were as follows:Inersustain^® C18 column (250 mm×4.6 mm,5 μm) was under column temperature of 35℃, the mobile phase consisted of acetonitrile-0.2% phosphoric acid(15:85)with a flow rate of 1.0 mL/min,and the UV detection wavelength was 277 nm. Ethyl acetate was used as extraction solvent. In order to determine PDG of the test solution under the chromatographic conditions, the number of theoretical plates and resolution were used as system suitability indicators. Linear regression on reference substance (PDG),linearity range and the precision, stability, and reproducibility of the analysis method, the recovery test of adding samples were all determined. The results showed that under the content determination method, the number of theoretical plates of PDG in the test solution was 8 588, and the resolution was 3.046. PDG performed good linear relation at the linear range between 6 and 192 μg/mL, and the related coefficient was 0.9996. The precision experiments showed that the relative standard deviation (RSD) of reference substance solution was 0.74%. The RSD of reproducibility and stability of PDG in the test solution was 4.50% and 2.69%, respectively. The average recovery was 98.74% with RSD 0.65% (n=9). Under the chromatographic conditions established above, the contents of PDG in the test sample were between 0.124 and 0.127 mg/mL. The conclusion was that the RP-HPLC method performed well system suitability, precision, reoroducibility, stability, and high recovery rate. Meanwhile this method was quick, simple and reliable. It could be used to determine the content of PDG in Eucommie ulmoides immunoenhancement liquids.