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。     

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。     

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。     

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。     

蜕皮激素溶液含量测定方法比较

比较了蜕皮激素溶液中β-蜕皮激素含量的两种仪器分析方法。紫外分光光度法分别采用对照品法和吸收系数法测定,高效液相色谱法采用Waters Symmetryshield RP18(4.6×250mm,粒径5μm)色谱柱,以乙腈-甲醇-水(1:2:4)为流动相,检测波长为242nm,流速1.0mL/min,外标法定量。     

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.     

RP-HPLC法测定杜仲增免液中松脂醇二葡萄糖苷的含量

试验旨在建立测定杜仲增免液中松脂醇二葡萄糖苷含量的RP-HPLC法。以Inersustain^® C18（250 mm×4.6 mm,5 μm）为色谱柱,乙腈-0.2%磷酸（15：85）为流动相,流速1.0 mL/min,柱温35℃,紫外检测波长277 nm。以乙酸乙酯作为提取溶剂,在所建立的色谱条件下测定供试品溶液,以理论塔板数和分离度作为系统适用性指标。对对照品松脂醇二葡萄糖苷溶液进行线性回归,确定线性范围,考察分析方法的精密度、稳定性、重现性,并进行加样回收试验。结果显示,用所建立的方法测定供试品溶液中松酯醇二葡萄糖苷理论塔板数为8 588,分离度为3.046。松脂醇二葡萄糖苷对照品溶液在6~192 μg/mL浓度范围内线性关系良好,相关系数为0.9996;精密度试验结果显示松脂醇二葡萄糖苷对照品溶液峰面积相对标准偏差（relative standard deviation,RSD）为0.74%;重现性和稳定性试验结果显示供试品溶液中松酯醇二葡萄糖苷峰面积RSD分别为4.50%和2.69%;平均加样回收率为98.74%,RSD为0.65%（n=9）;在所建立的色谱条件下,供试品中松脂醇二葡萄糖苷的平均含量为0.124~0.127 mg/mL。结果表明,应用该方法测定杜仲增免液中松脂醇二葡萄糖苷的含量,系统适用性好,精密度高,重现性和稳定性好,回收率高,快速简便、准确可靠,可作为杜仲增免液中松脂醇二葡萄糖苷含量测定方法。