Thomas R C, Hsi R S, Harpootlian H, Judy R W
J Pharm Sci. 1975 Aug;64(8):1360-6. doi: 10.1002/jps.2600640821.
Minoxidil (2,4-diamino-6-piperidinopyrimidine 3-oxide), a potent new hypotensive agent, was 14C-labeled in the 2-position of the pyrimidine ring in 17 percent yield from Ba14CO3. This material was used to study the absorption, distribution, and excretion of the drug in rats, dogs, and monkeys. Following oral administration of a single dose, the drug was rapidly and well absorbed and rapidly eliminated by each species as judged by plasma levels and urinary excretion of unchanged drug and total drug-related materials. Chronic oral administration of the drug at a high level (10 mg/kg) for 30 days slightly increased the rate of clearance of minoxidil and minoxidil-related material from circulation. Water diuresis, resulting from water loading of dogs, caused an even greater increase in the rates of disappearance of the drug and drug-related material. Whole-body autoradiography studies in rats showed that minoxidil was rapidly distributed following its oral and intravenous administration. It was subsequently concentrated, primarily in the excretory system. Minoxidil-related material was detected in aorta walls, but not in the CNS, following both routes of drug administration.
米诺地尔（2,4-二氨基-6-哌啶基嘧啶3-氧化物）是一种新型强效降压药，以碳酸钡14C为原料，在嘧啶环的2位进行14C标记，产率为17%。该物质用于研究大鼠、狗和猴子体内药物的吸收、分布和排泄情况。单次口服给药后，根据血浆水平以及未代谢药物和与药物相关的总物质的尿排泄情况判断，各物种对该药物的吸收迅速且良好，排泄也很快。以高剂量（10mg/kg）连续口服该药物30天，可使米诺地尔及其相关物质从循环中的清除率略有增加。给狗大量饮水导致水利尿，这使得药物及其相关物质的消失速率进一步大幅增加。对大鼠进行的全身放射自显影研究表明，米诺地尔经口服和静脉给药后分布迅速，随后主要在排泄系统中蓄积。两种给药途径后，在主动脉壁中均检测到米诺地尔相关物质，但在中枢神经系统中未检测到。
