生物利用度: 指药物剂型中能被吸收进入体循环的药物的相对分量及速度。即指药物被机体吸收的百分数。同一种药物,其生物利用度可有较大差别,这与药物的剂型(片剂、胶囊、冲剂)、药物的崩解时间等有关,同一药物的制剂由于各药厂的制造工艺不同,甚至同一药厂的生产批号不同的同一制剂,其生物利用度也可有较大差异。 首过效应: 口服药物进入机体后,药物通过胃肠道粘膜被吸收,然后进入肝门静脉。某些药物在通过肠粘膜及肝脏时,因经过灭活代谢而使进入体循环的药量减少,这 Bioavailability: The relative amount and rate of drug that can be absorbed into the systemic circulation in a pharmaceutical dosage form. Refers to the percentage of drug absorbed by the body. The same drug, its bioavailability may have a greater difference, and the drug formulations (tablets, capsules, granules), the disintegration time of the drug and the like, the same drug formulations due to the different manufacturing processes of the pharmaceutical companies, or even The same pharmaceutical production lot number of the same preparation, its bioavailability can have a greater difference. First pass effect: oral drugs into the body, the drug is absorbed through the gastrointestinal mucosa, and then enter the hepatic portal vein. Some drugs through the intestinal mucosa and liver, due to inactivated metabolism and reduce the volume into the systemic circulation, which