Sharma Nitish, Rao Surendra Singh, Kumar Namala Durga Atchuta, Reddy Annarapu Malleswara
Dr. Reddy's Laboratories Ltd IPDO, Bachupally, Hyderabad-500090, A.P, India, and J.N.T. University, Department of Chemistry, Kukatpally, Hyderabad-500085, A.P, India.
J AOAC Int. 2013 Sep-Oct;96(5):981-6. doi: 10.5740/jaoacint.11-489.
A selective, specific, and sensitive ultra-performance LC (UPLC) method was developed for determination of eszopiclone and its degradation products. The chromatographic separation was performed with a Waters ACQUITY UPLC system and BEH C18 column using gradient elution with mobile phases A and B. Mobile phase A was 0.01 M phosphate buffer with 0.2% (w/v) 1-octane sulfonic acid sodium salt as an ion pair reagent, adjusted pH 2.2 with orthophosphoric acid-acetonitrile (85 + 15, v/v). Mobile phase B was pH 2.2 buffer-acetonitrile (20 + 80, v/v). UV detection was performed at 303 nm. Eszopiclone and its impurities were chromatographed with a total run time of 13 min. A calibration study showed that the response for each of the impurities A, B, C, and D was linear between concentrations of 0.02 and 7.2 microg/mL (r2 > or = 0.999). The method was validated over this range for precision, intermediate precision, accuracy, linearity, and specificity. For the precision study, RSD of each impurity was <5% (n = 6). The method was found to be precise, accurate, linear, and specific. The proposed method was successfully used for determination of eszopiclone impurities in pharmaceutical preparations.
建立了一种选择性、特异性和灵敏的超高效液相色谱（UPLC）法用于测定艾司佐匹克隆及其降解产物。采用沃特世ACQUITY UPLC系统和BEH C18色谱柱进行色谱分离，使用流动相A和B进行梯度洗脱。流动相A为0.01 M磷酸盐缓冲液，含0.2%（w/v）1-辛烷磺酸钠盐作为离子对试剂，用正磷酸-乙腈（85 + 15，v/v）调节pH至2.2。流动相B为pH 2.2的缓冲液-乙腈（20 + 80，v/v）。在303 nm处进行紫外检测。艾司佐匹克隆及其杂质的色谱总运行时间为13分钟。校准研究表明，杂质A、B、C和D在0.02至7.2 μg/mL的浓度范围内响应呈线性（r2≥0.999）。该方法在该范围内进行了精密度、中间精密度、准确度、线性和特异性验证。对于精密度研究，各杂质的相对标准偏差（RSD）<5%（n = 6）。该方法被证明是精确、准确、线性和特异的。所提出的方法成功用于测定药物制剂中的艾司佐匹克隆杂质。
