Ibrahim Fawzia, Sharaf El-Din Mohie Khaled, Eid Manal Ibrahim, Wahba Mary Elias Kamel
Department of Analytical Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt.
Chem Cent J. 2011 May 9;5:24. doi: 10.1186/1752-153X-5-24.
An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn2+ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.6 mm id) stainless steel column at ambient temperature with UV-detection at 260 nm. A mobile phase containing 0.025%w/v Zn2+ in a mixture of (acetonitril/methanol; 1/4) and Britton Robinson buffer (65:35, v/v) adjusted to pH 4.2, has been used for the determination of ebastine at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 0.3 - 6.0 μg/ml with a detection limit (LOD) of 0.13 μg/ml, and quantification limit (LOQ) of 0.26 μg/ml. The proposed method was successfully applied for the analysis of ebastine in its dosage forms, the obtained results were favorably compared with those obtained by a comparison method. Furthermore, content uniformity testing of the studied pharmaceutical formulations was also conducted. The composition of the complex as well as its stability constant was also investigated. Moreover, the proposed method was found to be a stability indicating one and was utilized to investigate the kinetics of alkaline and ultraviolet induced degradation of the drug. The first-order rate constant and half life of the degradation products were calculated.
已开发出一种准确、简单、灵敏且选择性好的反相液相色谱法，用于测定药物制剂中的依巴斯汀。该方法基于所研究药物与Zn2+离子的络合能力。反相色谱分析采用ODS C18（150×4.6 mm内径）不锈钢柱，在室温下进行，于260 nm处进行紫外检测。流动相为在（乙腈/甲醇；1/4）和Britton Robinson缓冲液（65:35，v/v）的混合物中含有0.025%w/v Zn2+，pH调至4.2，以1 ml/min的流速用于测定依巴斯汀。校准曲线在0.3 - 6.0 μg/ml的浓度范围内呈线性，检测限（LOD）为0.13 μg/ml，定量限（LOQ）为0.26 μg/ml。所提出的方法成功应用于依巴斯汀剂型的分析，所得结果与通过对照方法获得的结果进行了良好比较。此外，还对所研究的药物制剂进行了含量均匀度测试。还研究了络合物的组成及其稳定常数。此外，发现所提出的方法是一种稳定性指示方法，并用于研究药物在碱性和紫外线诱导下的降解动力学。计算了降解产物的一级速率常数和半衰期。
