Flow Injection Analysis of Pharmaceutical Compounds VII. Determination of Some Anthelmintic and Antiprotozoal Compounds

A simple continuous flow injection analysis (FIA) with spectrophotometric detection of some anthelmintic and ant iprotozoal drugs is presented. These drugs are; oxamniquine (OX), thiabendazole (TBZ), mebendazole (MBZ), flubendazole (FBZ), diloxanide furoate (DF), metronidazole (MTZ) and tinidazole (TNZ).     

两种新型99mTcN核标记的甲硝唑类乏氧显像剂的制备及生物性能评价

为研制新的肿瘤乏氧显像剂, 设计合成了2-(2-甲基-5-硝基咪唑基)乙基氨荒酸钾(MNIE-DTC)和4-(2-甲基-5-硝基咪唑基)丁基氨荒酸钾(MNIB-DTC)两种氨荒酸盐配体, 并制得了相应的99mTcN核配合物99mTcN(MNIE-DTC)2和99mTcN(MNIB-DTC)2. 所获得的两种99mTcN核配合物均为电中性, 具有较高的体外稳定性. 在荷乳腺癌的TA-2小鼠体内分布实验结果显示, 两种配合物均具有一定的肿瘤摄取, 给药1 h后, 99mTcN(MNIE-DTC)2和99mTcN(MNIB-DTC)2的肿瘤摄取率分别为(0.50±0.01)%ID/g和(0.64±0.10)%ID/g. 注入肼苯哒嗪后, 两种配合物的肿瘤摄取明显增高, 表明这两种配合物都具有对乏氧肿瘤的选择性.     

拉曼光纤技术快速无损鉴别甲硝唑片

采用光纤探头直接放在甲硝唑片上进行检测,采集谱图,对拉曼光谱峰进行指认,并改变测定条件(药品隔铝塑包装、刮除包膜)进行测定。建立了光纤传感技术结合拉曼光谱快速无损鉴别甲硝唑片的方法,所测药物图谱峰形良好、峰强明显、指纹性强、测定快速准确,可瞬间获得片剂的特征图谱。样品无需进行前处理,可无损鉴别。药片检测时,是否隔铝塑包装和刮除包膜不影响谱图识别。本法快速、准确、专属性强、灵敏度高,可用于对甲硝唑片进行有效的鉴别。     

温度限制串联相关网络-近红外光谱法用于药物甲硝唑的质量控制

近红外漫反射光谱是一种简便、快速的有机物分析方法,样品不需处理即可直接测量,易于实现固态样非破坏测定.近红外漫反射光谱分析技术广泛应用于农业、食品、化妆品、烟草和石油等方面的组分分用近红外漫反射光谱法进行药品的非破坏性分析正成为国际热门课题.但近红外漫反射光谱的光谱范宽,吸收强度很弱,且组分间光谱严重重叠,给非破坏性分析带来了困难.而近红外漫反射光谱法与化量学相结合,能有效地解决光谱重叠带来的问题[1～3].     

Multicommutated generation of concentration gradients in a flow-batch system for metronidazole spectrophotometric determination in drugs

The titration by using the perchloric acid as titrant and malachite green as indicator is the classical method for the determination of metronidazole, 2-(2-methyl-nitroimidazol-1-yl) ethanol, in drugs. However, this procedure is slow, laborious and consumes great amount of reagents and samples. Moreover, it requires careful manipulation because the reagents cause irritation in the skin and in the eyes. To overcome these drawbacks an automatic system is proposed. It uses three-way solenoids valves, an open chamber and it exploits concentration gradients generated into the chamber in a multicommutated way. As the proposed system embodies the characteristics of flow-batch systems and of multicommutation techniques in flow, it is here named flow-batch-multicommutated titrator. The system is fully controlled by microcomputer running software written in LabView 5.1 graphic language. It processes 60 samples per hour with relative standard deviation smaller than 2.3% (n=6) and in each titration it consumes 2.5 and 1.5 ml of sample and titrant, respectively. By applying the paired t-test, no statistic differences at the 95% probability level between the results of the proposed system and classical titration were observed.     

碳糊电极测定甲硝唑的研究

报道了用碳糊电极测定甲硝唑的方法。在ｐＨ３．２的ＬｉＣｌ－ＨＣｌ电解溶液中，用二次导数阴极溶出伏安法测定甲硝唑。在碳糊电极上开路富集甲硝唑６０ｓ，然后记录其在－０．５８Ｖ的二次导数阴极溶出峰。溶出峰电流ｉｐ与甲硝唑浓度在３．０×１０－７～３．０×１０－６ｍｏｌ／Ｌ和３．０×１０－６～１．０×１０－４ｍｏｌ／Ｌ范围内呈良好的线性关系，相关系数分别为０．９９８６和０．９９９７，检出限为１．７×１０－７ｍｏｌ／Ｌ，相对标准偏差为６．０％（ｎ＝１０）。本方法直接用于甲硝唑片剂的测定，并用多种方法对甲硝唑在碳糊电极表面的反应机理进行了探讨。     

Preparation of a novel fluorescence probe based on covalent immobilization by emulsion polymerization and its application to the determination of metronidazole

A novel method of preparing fluorescence particle probe by emulsion polymerization with covalent immobilization of indicator dye was described. A terminal double bond was attached to 3-amino-9-ethylcarbazole (AEC) via methacryloyl chloride, and the resultant compound was copolymerized with butyl methacrylate. The obtained polymer particles were used as a fluorescence probe, which is almost free of dye leaching, and has higher photostability and lower toxicity in comparison with free AEC. This probe holds great potential for the applications in intracellular measurements. In present study the prepared probe was used for the determination of metronidazole. The results revealed that the probe showed good selectivity and had a linear response to the analyte in the range from 2.0 × 10⁻⁵ to 1.0 × 10⁻³ mol l⁻¹ with a detection limit of 9.0 × 10⁻⁶ mol l⁻¹.     

Formulation development and evaluation of metronidazole magnetic nanosuspension as a magnetic-targeted and polymeric-controlled drug delivery system

A nanosuspension of magnetically tagged metronidazole was developed by the solvent displacement method coupled with ultrasonication and was evaluated for its physicochemical properties. The drug release from metronidazole magnetic nanosuspension at pH 1.2 and 7.0 shows maximum correlation coefficient for zero order and Higuchi model, respectively. The anthelmintic activity of the formulated metronidazole magnetic nanosuspension was evaluated on Indian earthworms (Pheretima poi). Metronidazole magnetic nanosuspension at a dose of 10 and 50 mg/ml shortened by 31% and 34%, respectively, the mean time to death of the earthworms when compared against a non-magnetic metronidazole suspension. Thus, the developed metronidazole magnetic nanosuspension showed potent, controlled and targeted drug action and might be a good therapeutic avenue in combating infectious GI disorders.     

偏最小二乘法-BP 神经网络用于多组分药物测定

先将输入向量采用偏最小二乘法进行成分分析,再与ＢＰ神经网络法相结合,用于测定甲硝唑,头孢唑啉钠,维生素Ｂ６三给分。三给分的平均回收率及ＲＳＤ分别为９９．３％,０．７１％;９９．１％,０．９３％;９９．３％,２．８％。     

Electrocatalytic Reduction of Metronidazole on Bismuth Modified Pencil‐lead Electrode

We report a new and simple approach based on an experimental design method for the preparation of pencil‐lead electrode modified with bismuth thin film. The fabrication process consists of reduction of bismuth on the surface of electrode with potentiostate method. Response surface methodology was developed as experimental strategies for modeling and optimization of the influence of some variables on the performance of modified electrode. The electrocatalytic behavior of this modified electrode was exploited as a sensitive detection system for the mercury‐free reduction and determination of metronidazole in pharmaceutical and biological samples by using differential pulse voltammetry and amperometry methods.