Ramakrishna N V S, Vishwottam K N, Wishu S, Koteshwara M, Chidambara J
Biopharmaceutical Research, Suven Life Sciences Ltd., Serene Chambers, Road #7, Banjara Hills, Hyderabad 500034, India.
J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Sep 5;823(2):189-94. doi: 10.1016/j.jchromb.2005.06.036.
A simple, sensitive and selective HPLC method with UV detection (315 nm) was developed and validated for quantitation of entacapone in human plasma, the newest addition to the group of antiparkinsonian agents. Following a single-step liquid-liquid extraction (LLE) with ethyl acetate/n-hexane (30/70, v/v), the analyte and internal standard (rofecoxib) were separated using an isocratic mobile phase of 30 mM phosphate buffer (pH 2.75)/acetonitrile (62/38, v/v) on a reverse phase C18 column. The lower limit of quantitation was 25 ng/mL, with a relative standard deviation of less than 8%. A linear range of 25-2500 ng/mL was established. This HPLC method was validated with between-batch and within-batch precision of 2.2-4.2% and 1.7-7.8%, respectively. The between-batch and within-batch accuracy was 98.7-107.5% and 97.5-106.0%, respectively. Frequently coadministered drugs did not interfere with the described methodology. Stability of entacapone in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method is sensitive, simple and repeatable enough to be used in pharmacokinetic studies.
建立了一种简单、灵敏且具选择性的高效液相色谱法（HPLC），采用紫外检测（315 nm）对人血浆中恩他卡朋进行定量分析，恩他卡朋是抗帕金森病药物组中的最新成员。采用乙酸乙酯/正己烷（30/70，v/v）进行单步液-液萃取（LLE）后，在反相C18柱上，使用30 mM磷酸盐缓冲液（pH 2.75）/乙腈（62/38，v/v）的等度流动相分离分析物和内标（罗非昔布）。定量下限为25 ng/mL，相对标准偏差小于8%。建立了25 - 2500 ng/mL的线性范围。该HPLC方法的批间精密度和批内精密度分别为2.2 - 4.2%和1.7 - 7.8%，进行了验证。批间和批内准确度分别为98.7 - 107.5%和97.5 - 106.0%。常用的合并用药不干扰所述方法。恩他卡朋在血浆中的稳定性极佳，在样品处理（自动进样器）过程中无降解迹象，且在冷冻条件下储存30天也无降解。这种经过验证的方法灵敏、简单且可重复性强，足以用于药代动力学研究。
