Pieniaszek H J
Res Commun Chem Pathol Pharmacol. 1975 Nov;12(3):571-81.
A simple and convenient colorimetric method is described for the quantitative determination of 5-aminosalicylic acid (5-ASA) and N-acetyl-5-ASA in urine and feces after oral administration of salicylazosulfa-pyridine (SASP), the drug of choice in the treatment of ulcerative colitis. N-acetyl-5-ASA is extracted directly from the acidified biological specimen, deacetylated, and the liberated 5-ASA subjected to a modified Bratton-Marshall reaction. The 5-ASA present in the specimen must be acetylated with acetic anhydride prior to extraction. The violet colored product of the Bratton-Marshall reaction has a lambdamax of 560 nm and conforms to Beer's law over the concentration range of 0-70 umg/ml. Average recoveries (+/- S.D., N = 6) OF 5-ASA added to rat and human urine and rat fecal homogenates were 91.6 +/- 4.9%, 102 +/- 6.0%, and 71.0 +/- 4.8%, respectively. Interference by SASP and its sulfapyridine metabolities is negligible. As demonstrated, the colorimetric method is of sufficient sensitivity for application in most metabolic and pharmacokinetic studies conducted with SASP in laboratory animals and man.
本文描述了一种简单便捷的比色法，用于定量测定口服柳氮磺胺吡啶（SASP，治疗溃疡性结肠炎的首选药物）后尿液和粪便中的5-氨基水杨酸（5-ASA）和N-乙酰-5-ASA。N-乙酰-5-ASA直接从酸化的生物样本中提取，脱乙酰化，然后将释放出的5-ASA进行改良的Bratton-Marshall反应。样本中存在的5-ASA在提取前必须用乙酸酐乙酰化。Bratton-Marshall反应产生的紫色产物的最大吸收波长为560 nm，在0-70 μg/ml的浓度范围内符合比尔定律。添加到大鼠和人尿液以及大鼠粪便匀浆中的5-ASA的平均回收率（±标准差，N = 6）分别为91.6±4.9%、102±6.0%和71.0±4.8%。SASP及其磺胺吡啶代谢物的干扰可忽略不计。结果表明，该比色法灵敏度足以应用于大多数在实验动物和人体中进行的SASP代谢和药代动力学研究。
