Faculty of Pharmacy, Department of Pharmaceutical Sciences, Alma Mater Studiorum-University of Bologna, I-40126 Bologna, Italy.
Talanta. 2009 Nov 15;80(1):279-85. doi: 10.1016/j.talanta.2009.06.074. Epub 2009 Jul 8.
Diazepam is frequently used as an adjuvant during antidepressant therapy. Recently, some studies have suggested that the treatment with benzodiazepines could have different efficacy in depressed patients as opposed to non-depressed ones. To clarify the matter, a study is currently underway, regarding the drug metabolism in rats. In order to obtain a more complete and significant set of data, the main diazepam metabolites have also been considered, namely: nordiazepam, temazepam and oxazepam. A feasible and reliable HPLC method has been developed for the simultaneous determination of these compounds in plasma and brain tissue of rats. The method has been applied to "normal" rats and to genetic rat models of depression in order to estimate drug metabolism in different breeds. Analyte separation was achieved on a C8 reversed phase column using an acidic phosphate buffer/acetonitrile mixture as the mobile phase. The detection wavelength was 238 nm. An original sample pre-treatment, based on solid-phase extraction (SPE) was developed in order to eliminate endogenous interference, using only 250 microL of matrix (brain homogenate or plasma) for a complete analysis. The method has been validated with good results in terms of precision, extraction yield, sensitivity, selectivity and accuracy on both matrices and has been successfully applied to samples from some rats subjected to the preliminary study. The obtained data will hopefully contribute to the clarification of possible differences between depressed and non-depressed subjects with respect to benzodiazepine biotransformation.
地西泮常被用作抗抑郁治疗的辅助药物。最近，一些研究表明，与非抑郁患者相比，苯二氮䓬类药物治疗在抑郁患者中可能具有不同的疗效。为了澄清这一问题，目前正在对大鼠的药物代谢进行研究。为了获得更完整和更有意义的数据集，还考虑了地西泮的主要代谢物，即：去甲西泮、替马西泮和奥沙西泮。已开发出一种可行且可靠的 HPLC 方法，用于同时测定大鼠血浆和脑组织中的这些化合物。该方法已应用于“正常”大鼠和遗传性抑郁大鼠模型，以评估不同品种的药物代谢。分析物的分离是在 C8 反相柱上实现的，使用酸性磷酸盐缓冲液/乙腈混合物作为流动相。检测波长为 238nm。为了消除内源性干扰，开发了一种基于固相萃取（SPE）的原始样品预处理方法，仅需 250μL 基质（脑匀浆或血浆）即可进行完整分析。该方法在两种基质上均具有良好的精密度、提取回收率、灵敏度、选择性和准确性验证结果，并已成功应用于一些接受初步研究的大鼠的样品中。获得的数据有望有助于澄清抑郁和非抑郁受试者在苯二氮䓬类生物转化方面的可能差异。
