Department of Psychiatry and Psychotherapy, Clinical Pharmacology/Psychopharmacology, University of Regensburg, Universitätsstrasse 84, D-93055 Regensburg, Germany.
Ther Drug Monit. 2012 Dec;34(6):702-12. doi: 10.1097/FTD.0b013e31826933ab.
In the near future, there will be no innovative drug principle for the treatment of dementia. Therefore, optimizing the efficacy of a drug is at present the most promising way to exploit its full pharmacological potential.
A high performance liquid chromatography with ultraviolet assay for memantine in serum from demented patients has been developed and validated. The analytical procedure involves offline solid phase extraction cartridges. Because memantine molecules lack chromophoric π-electrons, a derivatization with dansyl chloride was required for detection by ultraviolet (UV) photometry. Analyses were performed on a Dionex high-performance liquid chromatography system with a Phenomenex Luna Phenyl-Hexyl analytical column and 0.02 mol/L potassium dihydrogen phosphate buffer/acetonitrile (40/60 V/V) as mobile phase at a flow rate of 0.4 mL/min. Dansylated memantine was detected at 218 nm; 2 more ultraviolet wavelengths at 254 nm and 336 nm were used as an overlay-control check.
The retention time for dansylated memantine was 17.1 ± 0.2 minutes. The calibration curve was linear over a concentration range from 5 to 160 ng/mL (n = 8/r² > 0.999). The method had an accuracy of >90%. Intra-assay and inter-assay coefficients of variation were <5% and <13%, respectively, at 3 different concentrations. The limit of quantification and the limit of detection were 2.9 ng/mL and 0.8 ng/mL, respectively. Among 100 substances prescribed as comedications in the treatment of dementia only fluvoxamine and zuclopenthixole showed retention times close to dansylated memantine (17.8 minutes and 18.1 minutes, respectively). However, these 2 drugs were removed from patients' specimens during solid-phase extraction sample preparation.
The method is applicable under conditions of daily routine as has been demonstrated by application of the method to patient serum samples. The quantification of 29 samples showed that memantine concentrations suggested as "therapeutic" in the literature may only be reached by high doses of memantine.
在不久的将来，针对痴呆症的治疗将不会有新的药物出现。因此，优化现有药物的疗效是目前充分挖掘其全部药理潜力最有前景的方法。
建立并验证了高效液相色谱法-紫外检测法检测痴呆患者血清中氨甲环酸的浓度。该分析方法包括离线固相萃取小柱。由于氨甲环酸分子缺乏发色π电子，因此需要用丹磺酰氯衍生化，然后用紫外（UV）分光光度法进行检测。在 Dionex 高效液相色谱系统上进行分析，采用 Phenomenex Luna Phenyl-Hexyl 分析柱，以 0.02 mol/L 磷酸二氢钾/乙腈（40/60 V/V）为流动相，流速为 0.4 mL/min。丹磺酰化氨甲环酸在 218 nm 处检测；另外 2 个紫外波长 254 nm 和 336 nm 用于叠加控制检查。
丹磺酰化氨甲环酸的保留时间为 17.1 ± 0.2 分钟。校准曲线在 5 至 160 ng/mL 浓度范围内呈线性（n = 8/r²>0.999）。方法的准确度>90%。在 3 个不同浓度下，日内和日间变异系数分别<5%和<13%。定量下限和检测下限分别为 2.9 ng/mL 和 0.8 ng/mL。在治疗痴呆症的共用药中，有 100 种物质被规定为处方，但只有氟伏沙明和左氯噻嗪的保留时间接近丹磺酰化氨甲环酸（分别为 17.8 分钟和 18.1 分钟）。然而，这两种药物在固相萃取样品制备过程中从患者标本中被去除。
该方法适用于日常工作条件，已通过对患者血清样本的应用得到验证。对 29 个样本的定量结果表明，文献中报道的“治疗”浓度可能仅通过高剂量的氨甲环酸才能达到。
