Five ester prodrugs of 2'3'-dideoxyinosine (DDI) were synthesized for the purpose of improving oral bioavailability. The prodrugs, acetate (C2-DDI), octanoate (C8-DDI), stearate (C18-DDI), benzoate (Bz-DDI), and hemisuccinate (Suc-DDI) were proved to quantitatively regenerate their parent drug by enzymatic hydrolysis. Though the chemical stability of the prodrugs under acidic conditions was not improved, their solubility in water was significantly decreased by esterification, except for Suc-DDI. Bioavailability was evaluated by oral administration to rats. Two hydrophobic prodrugs (C8-DDI and Bz-DDI) showed higher absolute bioavailability (23.5% and 31.0%, respectively) than did DDI (15.2%), though that of C2-DDI (11.5%) and Suc-DDI (4.5%) was poor.
为了提高口服
生物利用度,我们合成了五种 2'3'-dideoxyinosine (DDI) 的
酯类原药。经证明,
醋酸酯(C2-DDI)、
辛酸酯(C8-DDI)、
硬脂酸酯(C18-DDI)、
苯甲酸酯(Bz-DDI)和半
琥珀酸酯(Suc-DDI)原药在酶
水解作用下可定量生成母药。虽然这些原药在酸性条件下的
化学稳定性没有得到改善,但除 Suc-DDI 外,它们在
水中的溶解度因酯化作用而显著降低。通过给大鼠口服评估了
生物利用度。两种疏
水性原药(C8-DDI 和 Bz-DDI)的绝对
生物利用度(分别为 23.5% 和 31.0%)高于 DDI(15.2%),但 C2-DDI (11.5%)和 Suc-DDI (4.5%)的
生物利用度较低。