电位滴定法测定肿节风注射液中总有机酸含量

目的 建立肿节风注射液中总有机酸含量的测定方法.方法 采用电位滴定法进行含量测定.结果 6个批次的肿节风注射液总有机酸含量(以反丁烯二酸计)每支在3.06～3.16 mg之间,RSD=1.20％ (n=6),反丁烯二酸加样回收率为96.28％～101.56％.结论 该方法简便快速,精密度好,准确度高,重现性好可以作为肿节风注射液中总有机酸的质量控制方法之一.     

Anti-inflammatory property of n-hexadecanoic acid: structural evidence and kinetic assessment

Ester bond hydrolysis of membrane phospholipids by Phospholipase A₂ and consequent release of fatty acids are the initiating steps of inflammation. It is proposed in this study that the inhibition of phospholipase A₂ is one of the ways to control inflammation. Investigations are carried out to identify the mode of inhibition of phospholipase A₂ by the n‐hexadecanoic acid. It may help in designing of specific inhibitors of phospholipase A₂ as anti‐inflammatory agents. The enzyme kinetics study proved that n‐hexadecanoic acid inhibits phospholipase A₂ in a competitive manner. It was identified from the crystal structure at 2.5 Å resolution that the position of n‐hexadecanoic acid is in the active site of the phospholipase A₂. The binding constant and binding energy have also been calculated using Isothermal Titration Calorimetry. Also, the binding energy of n‐hexadecanoic acid to phospholipase A₂ was calculated by in silico method and compared with known inhibitors. It may be concluded from the structural and kinetics studies that the fatty acid, n‐hexadecanoic acid, is an inhibitor of phospholipase A₂, hence, an anti‐inflammatory compound. The inferences from the present study validate the rigorous use of medicated oils rich in n‐hexadecanoic acid for the treatment of rheumatic symptoms in the traditional medical system of India, Ayurveda.     

Safety and tolerability of once-daily versus twice-daily memantine: a randomised, double-blind study in moderate to severe Alzheimer's disease

OBJECTIVE: To assess the safety and tolerability of three different dosing schedules of memantine in patients with moderate to severe Alzheimer's disease (AD). METHOD: This 12-week, randomised, double-blind study, investigated three dosing schedules of memantine: OD1 (20 mg once daily with a 1-step up-titration); OD3 (20 mg once daily with a 3-step up-titration); and BID3 (10 mg twice daily with a 3-step up-titration as currently recommended in the memantine labelling). The study comprised 78 patients with moderate to severe AD (DSM-IV-TR criteria; MMSE score < or = 18), 70% of whom were on stable dosing of acetylcholinesterase inhibitor (AChEI) initiated > or = 3 months prior to study start. Safety and tolerability were assessed by the number of withdrawals, adverse events (AEs) and monitoring of vital signs. RESULTS: The number of patient withdrawals was low: 3 of 27 in OD1, 1 of 25 in OD3 and 2 of 26 in BID3. One or more AEs were reported in 9 patients in OD1, 7 patients in OD3 and 12 patients in BID3. Most AEs were mild or moderate, and typical for the population studied; no clinically important differences in AEs or vital signs were observed between the different dosing schedules. There were no between-group differences in efficacy, as assessed by clinical global severity and clinical global change. These results are consistent with the good safety profile of memantine observed in larger studies. CONCLUSIONS: Although relatively small in size, the study indicates that once-daily dosing and twice-daily dosing of memantine are similar in terms of safety and tolerability.     

部分中药材二氧化硫残留量检测

目的测定部分中药材的二氧化硫残留量。方法使用酸蒸馏碘滴定法。结果9个中药材样品全部都有二氧化硫残留,均超过30μg·kg^-1。结论二氧化硫熏蒸中药现象仍十分普遍,国家有关部门应尽快出台中药二氧化硫残留量测定的方法及限量的法定标准。     

盐酸普罗帕酮含量测定方法改进

目的：建立盐酸普罗帕酮非水滴定中革除汞盐的含量测定方法。方法：采用以无水甲酸-醋酐（1：50）为溶剂的高氯酸电位滴定法。结果：革除汞盐后方法含量测定结果与原方法结果基本一致,可以代替原方法。结论：方法简便、易行,可用于盐酸普洛帕酮的质量控制。     

醇中碱滴定测定利可君原料的含量

目的:建立测定利可君原料含量的无苯污染的容量分析方法.方法:以乙醇为溶剂,用氢氧化钠滴定液(0.1 mol·L-1)滴定,电位法指示终点.结果:该法与国家标准方法测定结果一致.结论:该方法简便、准确、环保,适用于利可君的含量测定.     

三种方法检验盐酸左旋咪唑片剂含量的方法比较

目的 筛选比较各国药典中盐酸左旋咪唑片含量测定方法的优异.方法 利用重现实验和回收实验重点考查<中国药典>和<印度药典>所采用的高氯酸非水滴定方法和<美国药典>采用的高效液相梯度洗脱方法.结果 <中国药典>方法回收率为100.09%(RSD=3.66%);<印度药典>方法回收率为96.13%(RSD=0.86%);<...     

Directed epitope delivery across the Escherichia coli outer membrane through the porin OmpF

The porins OmpF and OmpC are trimeric β-barrel proteins with narrow channels running through each monomer that exclude molecules > 600 Da while mediating the passive diffusion of small nutrients and metabolites across the Gram-negative outer membrane (OM). Here, we elucidate the mechanism by which an entire soluble protein domain (> 6 kDa) is delivered through the lumen of such porins. Following high-affinity binding to the vitamin B(12) receptor in Escherichia coli, the bacteriocin ColE9 recruits OmpF or OmpC using an 83-residue intrinsically unstructured translocation domain (IUTD) to deliver a 16-residue TolB-binding epitope (TBE) in the center of the IUTD to the periplasm where it triggers toxin entry. We demonstrate that the IUTD houses two OmpF-binding sites, OBS1 (residues 2-18) and OBS2 (residues 54-63), which flank the TBE and bind with K(d)s of 2 and 24 μM, respectively, at pH 6.5 and 25 oC. We show the two OBSs share the same binding site on OmpF and that the colicin must house at least one of them for antibiotic activity. Finally, we report the structure of the OmpF-OBS1 complex that shows the colicin bound within the porin lumen spanning the membrane bilayer. Our study explains how colicins exploit porins to deliver epitope signals to the bacterial periplasm and, more broadly, how the inherent flexibility and narrow cross-sectional area of an IUP domain can endow it with the ability to traverse a biological membrane via the constricted lumen of a β-barrel membrane protein.     

眼内灌注液中氯化钙含量测定方法改良

目的对眼内灌注液中氯化钙含量测定终点判断方法的改良。方法按文献[1]方法加入试剂和被测物,然后加热再按规定测定氯化钙含量。结果测定终点突跃明显,终点容易判断,误差较小。结论本方法准确可靠。     

电位滴定法测定酮康唑含量能力验证的结果分析

以酮康唑为模型药物,统计了CNAS T0382电位滴定法测定药品含量能力验证的结果,并对离群数据进行技术分析.