巴比土类药物水中难溶(0.05～2 mg/100ml)。作者等研究利用药物前体改善溶解度以解决制剂上、生物利用度以及临床上的使用问题。马龙尿酸(Malon-uric acid)的各种烷基酯,在中性或偏碱性溶液中可迅速和定量地分子内环合生成巴比土类,如在马龙尿酸酯的醇基部位引入一极性基团,则可获得在胃肠 pH 中水 Barbadi soil water insoluble (0.05 ~ 2 mg / 100ml). The authors studied the use of prodrugs to improve solubility to address formulation, bioavailability, and clinical use issues. Various alkyl esters of Malon-uric acid are rapidly and quantitatively cyclized intramolecularly to form barbiturates in neutral or alkaline solutions such as those introduced at the alcohol group of malonurilate A polar group, then the water in gastrointestinal pH can be obtained