不同药厂生产的地高辛片剂,虽每片含量相同,但血中的药物浓度可相差4～7倍之多,甚至同一药厂不同批号的地高辛片剂也有此种现象。显然,这是由于生物可用度(Bioavailability)差异的影响。通常说来,生物可用度是指一定剂量一定剂型的药物以活性形式进入循环系统的速度和量。我们通常采用血浆药物浓度作为衡量生物可用度的指标。其计算公式如下: Different pharmaceutical companies produce digoxin tablets, although the same content of each piece, but the blood drug concentration can vary 4 to 7 times as much, and even different batches of the same pharmaceutical factory digoxin tablets also have this phenomenon. Obviously, this is due to the difference in Bioavailability. In general, bioavailability refers to the rate and amount of drug in a dosage form entering a circulatory system in an active form. We usually use plasma drug concentration as a measure of bioavailability. The formula is as follows: