Arena C, Fung H L
J Pharm Sci. 1980 Mar;69(3):356-8. doi: 10.1002/jps.2600690331.
A qualitative relationship between in vitro transport and in vivo absorption of sodium gamma-hydroxybutyrate and gamma-butyrolactone was demonstrated. As with other short-chain acids, sodium gamma-hydroxybutyrate showed capacity-limited transport in vitro, consistent with the previous observation that this drug exhibited slower in vivo absorption with increasing dose. The prodrug lactone, on the other hand, showed a higher intestinal flux than the acid in the everted gut, and in vivo absorption also was more rapid. Capacity-limited transport and absorption of the lactone appeared less evident. Thus, the increased oral hypnotic activity of the lactone over that of the acid most likely is a result of its more favorable intestinal transport characteristics.
已证明γ-羟基丁酸钠和γ-丁内酯的体外转运与体内吸收之间存在定性关系。与其他短链酸一样，γ-羟基丁酸钠在体外表现出转运能力受限，这与之前观察到的该药物随着剂量增加体内吸收变慢的现象一致。另一方面，前药内酯在外翻肠囊中显示出比酸更高的肠通量，并且体内吸收也更快。内酯的转运和吸收能力受限似乎不太明显。因此，内酯比酸具有更高的口服催眠活性很可能是其更有利的肠道转运特性的结果。
