Kumar Namasani Santhosh, Rani Avula Prameela, Visalakshi Telu, Sekharan Chandra Bala
University College of Pharmaceutical Sciences, Acharya Nagarjuna University, Nagarjuna nagar, India-522 510.
Adv Pharm Bull. 2013;3(1):231-7. doi: 10.5681/apb.2013.038. Epub 2013 Feb 7.
Ambrisentan (ABS) is an antihypertensive drug used in the treatment of pulmonary atrial hypertension. The survey of literature for ABS revealed only two spectrophotometric methods for its quantification. The reported methods lack the sensitivity. This study is aimed at developing two sensitive extractive spectrophotometric methods for the determination of ABS in bulk and in tablets.
The proposed methods are based on the formation of colored chloroform extractable ion-pair complexes of ABS with methylene blue (MB method) and safranine O (SO method) in buffered solution at pH 9.8. The extracted complexes showed maximum absorbance at 525 and 515 nm for methylene blue and safranine O, respectively.
In both the methods, the calibration curve was linear from 1-15 µg mL(-1) of drug. Apparent molar absorpitivities were 1.7911 x 10(5), 2.3272 x 10(5) L mol(-1) cm(-1); Sandell's sensitivities were 0.0215, 0.0162 µg cm(-2); LOD were 0.182, 0.175 µg mL(-1); LOQ were 0.551, 0.531 µg mL(-1) for methods MB and SO, respectively. The relative standard deviation and percent recovery ranged from 0.206-1.310% and 99.0-101.5%, respectively.
The results demonstrate that the proposed methods are sensitive, precise, accurate and inexpensive. These methods can easily be used for the assay of ABS in quality control laboratories.
安立生坦（ABS）是一种用于治疗肺动脉高压的抗高血压药物。对ABS的文献调研显示，仅发现两种用于其定量分析的分光光度法。所报道的方法缺乏灵敏度。本研究旨在开发两种灵敏的萃取分光光度法，用于测定原料药和片剂中的ABS。
所提出的方法基于在pH 9.8的缓冲溶液中，ABS与亚甲蓝（MB法）和番红O（SO法）形成可被氯仿萃取的有色离子对络合物。对于亚甲蓝和番红O，萃取得到的络合物分别在525 nm和515 nm处显示最大吸光度。
在两种方法中，药物浓度在1 - 15 μg mL⁻¹范围内校准曲线呈线性。表观摩尔吸光系数分别为1.7911×10⁵、2.3272×10⁵ L mol⁻¹ cm⁻¹；桑德尔灵敏度分别为0.0215、0.0162 μg cm⁻²；检测限分别为0.182、0.175 μg mL⁻¹；定量限分别为0.551、0.531 μg mL⁻¹，分别对应MB法和SO法。相对标准偏差和回收率分别在0.206 - 1.310%和99.0 - 101.5%范围内。
结果表明所提出的方法灵敏、精密、准确且成本低廉。这些方法可轻松用于质量控制实验室中ABS的测定。
