Dravid Prajakta V, Bhamidipati Ravi Kanth, Mullangi Ramesh, Srinivas Nuggehally R
Drug Metabolism and Pharmacokinetics, Discovery Research, Dr Reddy's Laboratories Ltd, Miyapur, Hyderabad (India).
Arzneimittelforschung. 2005;55(4):239-44. doi: 10.1055/s-0031-1296851.
An isocratic simple, specific, sensitive and reproducible high performance liquid chromatography (HPLC) method was developed and validated for the estimation of DRF-6196, a novel oxazolidinone in mouse plasma. This method involves a simple liquid/liquid extraction of DRF-6196 and the internal standard (IS; chlorzoxazone, CAS 95-25-0) from plasma into dichloromethane/ethyl acetate mixture that was evaporated under nitrogen. The HPLC analysis was carried out on an Inertsil ODS 2 column using 0.01 mol/L potassium dihydorgen ortho phosphate (pH 3.2) and acetonitrile (65:35, v/v) as mobile phase. The eluate was monitored using an UV detector set at 266 nm. Ratio of peak area of analyte to IS was used for quantification of plasma samples. The retention time of DRF-6196 and IS were 8.2 and 11.1 min, respectively. The assay was linear (r2 > 0.999) in the concentration range 0.1-50 microg/ml. Absolute recovery for analyte and IS was > 94 % from mouse plasma. The lower limit of quantification (LLOQ) of DRF-6196 was 0.1 microg/ml. The inter- and intra-day precision in the measurement of quality control (QC) samples, 0.1, 0.3, 15.0 and 40.0 microg/ml, were in the range 3.64 to 9.51 % relative standard deviation (RSD) and 0.92 to 6.23 % RSD, respectively. Accuracy in the measurement of QC samples was in the range 88.15 to 106.05 % of the nominal values. The analyte and IS were stable in the stability studies viz., benchtop, autosampler and freeze/thaw cycles. The stability of DRF-6196 was established for 1 month at -80 degrees C. The assay method was successfully applied to a pharmacokinetic study of DRF-6196 in mice.
开发并验证了一种等度洗脱的简单、特异、灵敏且可重现的高效液相色谱（HPLC）方法，用于测定小鼠血浆中的新型恶唑烷酮DRF-6196。该方法包括将DRF-6196和内标（IS；氯唑沙宗，CAS 95-25-0）从血浆中通过简单的液-液萃取至二氯甲烷/乙酸乙酯混合物中，然后在氮气下蒸发。HPLC分析在Inertsil ODS 2柱上进行，使用0.01 mol/L磷酸二氢钾（pH 3.2）和乙腈（65:35，v/v）作为流动相。使用设置在266 nm的紫外检测器监测洗脱液。分析物与内标的峰面积比用于血浆样品的定量。DRF-6196和内标的保留时间分别为8.2分钟和11.1分钟。该测定法在0.1-50μg/ml的浓度范围内呈线性（r2>0.999）。分析物和内标从小鼠血浆中的绝对回收率>94%。DRF-6196的定量下限（LLOQ）为0.1μg/ml。质量控制（QC）样品（0.1、0.3、15.0和40.0μg/ml）测定的日间和日内精密度，相对标准偏差（RSD）分别在3.64%至9.51%和0.92%至6.23%范围内。QC样品测定的准确度在标称值的88.15%至106.05%范围内。分析物和内标在稳定性研究（即台式、自动进样器和冻融循环）中稳定。DRF-6196在-80℃下的稳定性确定为1个月。该测定方法已成功应用于DRF-6196在小鼠体内的药代动力学研究。
