Farhadi Khalil, Hatami Mehdi, Forough Mehrdad, Molaei Rahim
Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran.
Bioanalysis. 2013 Mar;5(6):701-10. doi: 10.4155/bio.13.23.
A dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet was developed and validated for the extraction of propranolol enantiomers from human plasma. The studied enantiomers were extracted from diluted and alkalized plasma samples using 1-undecanol as the extracting solvent. HPLC-fluorescence detection analyses were carried out on a chiral column, using n-hexane-ethanol (80:20, v/v) plus 0.2% triethylamine as the mobile phase, at a flow rate of 0.8 ml/min. The significant factors in the microextraction procedure, including extracting and disperser solvents volume, solution pH and salt contents were optimized by using a central composite design and the response surface methodology.
Under optimized conditions, the mean recoveries were approximately 14% with linear responses over the 0.5-100 ng/ml concentration range for both enantiomers. The LOQ was 0.5 ng/ml (S/N = 10). Intra-day (n = 5) and inter-day (n = 3) assay precision (1 and 50 ng/ml) showed RSD lower than 8 and 9.5% for studied enantiomers, respectively. Finally, the method was successfully used for the determination of propranolol enantiomers in plasma samples obtained after single drug administration of racemic propranolol tablet to three healthy volunteers. The plasmatic concentrations of (-)-(S)-PROP were higher than those of (+)-(R)-PROP in all times after oral administration of the racemic drug.
The obtained results proved that the proposed method is a powerful technique for sample preparation, providing suitable recoveries, efficient cleanup, high selectivity and sensitivity and low consumption of organic solvent for determination of the studied enantiomers in plasma samples after oral administration of the racemic drug to volunteers.
建立了一种基于漂浮有机液滴固化的分散液液微萃取方法，并对其从人血浆中提取普萘洛尔对映体的性能进行了验证。使用1-十一醇作为萃取溶剂，从稀释并碱化的血浆样品中提取所研究的对映体。采用手性柱进行HPLC-荧光检测分析，以正己烷-乙醇（80:20，v/v）加0.2%三乙胺作为流动相，流速为0.8 ml/min。采用中心复合设计和响应面法对微萃取过程中的重要因素，包括萃取剂和分散剂体积、溶液pH值和盐含量进行了优化。
在优化条件下，两种对映体的平均回收率约为14%，在0.5-100 ng/ml浓度范围内呈线性响应。定量限为0.5 ng/ml（信噪比=10）。日内（n = 5）和日间（n = 3）分析精密度（1和50 ng/ml）表明，所研究对映体的相对标准偏差分别低于8%和9.5%。最后，该方法成功用于测定三名健康志愿者单次口服消旋普萘洛尔片后获得的血浆样品中普萘洛尔对映体。口服消旋药物后，所有时间点(-)-(S)-普萘洛尔的血浆浓度均高于(+)-(R)-普萘洛尔。
所得结果证明，所提出的方法是一种强大的样品制备技术，为口服消旋药物给志愿者后血浆样品中所研究对映体的测定提供了合适的回收率、有效的净化、高选择性和灵敏度以及低有机溶剂消耗。
