Assessment of the combined approach of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines using bupivacaine as a model drug
作者:Anders Bach Nielsen、Karla Frydenvang、Tommy Liljefors、Anders Buur、Claus Larsen
DOI:10.1016/j.ejps.2004.09.012
日期:2005.1
correlations between salt solubility and crystal packing modes. Alkyl groups were methyl, ethyl, propyl, and butyl and the derivatives were isolated as their iodide salts. Chloride, mesylate, formate, acetate, glycolate, and tosylate salts were obtained by anion exchange of the N-methyl-bupivacaine derivative. N-Alkylation and salt formation afforded quaternary ammonium salts possessing pH-independent
已显示水溶性较差的叔胺的季前药类型与母体胺相比显示出显着提高的溶解度。在本研究中,已使用布比卡因作为模型化合物研究了N-烷基化和盐形成共同增强叔胺的水溶性的综合作用。包括对选定盐的X射线结构分析,以研究盐溶解度和晶体堆积模式之间潜在的相关性。烷基为甲基,乙基,丙基和丁基,并分离出其碘化物盐形式的衍生物。通过N-甲基-布比卡因衍生物的阴离子交换获得氯化物,甲磺酸盐,甲酸盐,乙酸盐,乙醇酸盐和甲苯磺酸盐。N-烷基化和盐的形成提供了季铵盐,其季铵盐具有与pH无关的水溶性,远远超过了母体叔胺的溶解度(在pH 8时高达3200)。对于N-烷基化的布比卡因衍生物的碘盐,观察到溶解度随烷基链长度的增加而适度降低。在N-甲基-布比卡因衍生物的情况下,抗衡离子的变化对溶解度有显着影响,碘化物盐的溶解度比氯化物盐低200倍。X射线分析表明,烷基取代基和阴离子抗衡离子都影响盐的堆积方式,但是,即使对于一系列密切