Vitamin C and 6-amino-vitamin C conjugates of diclofenac: synthesis and evaluation
Vitamin C and 6-amino-vitamin C conjugates of diclofenac: synthesis and evaluation
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DOI：
10.1016/j.ijpharm.2004.07.054
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发表时间：
2005-03-03
影响因子：
5.8
通讯作者：
Manfredini, S
中科院分区：
文献类型：
--
作者：
Dalpiaz, A;Pavan, B;Manfredini, S
制备双氯芬酸（Diclo）、其抗坏血酸（AA）或6-氨基-AA（AA-NH 2）前药（AA-Diclo或AA-NH-Diclo），并在人视网膜色素上皮（HRPE）细胞上进行评价，以研究其与维生素C转运蛋白SVCT 2相互作用的能力及其细胞摄取。此外，这些化合物在生理液体中的稳定性进行了研究。对于动力学实验，将AA-Diclo在Tris-HCl缓冲液、人血浆或全血中孵育。通过HPLC分析提取的样品。AA-Diclo在缓冲液、血浆（t（1/2）约10 h）和全血（t（1/2）约3.5 h）中按照一级动力学水解。通过将[C-14]AA和上述未标记的化合物加入平板接种的HRPE细胞中进行转运和抑制试验。将HRPE细胞与浓度递增的未标记化合物一起孵育，然后进行HPLC分析，测量细胞内积累。Diclo作为AA转运的非竞争性抑制剂，显示出Na+依赖性和抗坏血酸盐非依赖性摄取。AA-Diclo表现为竞争性抑制剂，但不被转运到细胞内，而其类似物AA-NH-Diclo显示出降低的抑制活性。稳定性研究表明，AA-Diclo是一种潜在的候选药物，可增强Diclo在体内的短半衰期。在HRPE细胞上发现双氯芬酸的Na+依赖性转运蛋白为双氯芬酸靶向进入大脑开辟了新的前景。(C)2004 Elsevier B. V.保留所有权利。
Diclofenac (Diclo), its ascorbic acid (AA) or 6-amino-AA (AA-NH2) pro-drugs (AA-Diclo or AA-NH-Diclo) were prepared and evaluated on human retinal pigment epithelium (HRPE) cells to investigate their ability to interact with the vitamin C transporter SVCT2 and their cellular uptake. Furthermore, stabilities in physiological fluids of these compounds were investigated. For kinetic experiments, AA-Diclo was incubated in Tris-HCl buffer, human plasma or whole blood. The extracted samples were analysed by HPLC. AA-Diclo was hydrolysed following first order kinetics in buffer, plasma (t(1/2) about 10 h) and whole blood (t(1/2) about 3.5 h). Transport and inhibition assays were performed by adding [C-14]AA and the above-mentioned unlabelled compounds to plated HRPE cells. Intracellular accumulation was measured incubating HRPE cells with increasing concentrations of unlabelled compounds, following by HPLC analysis. Diclo resulted as a non-competitive inhibitor of AA-transport, showing a Na+-dependent and ascorbate-independent uptake. AA-Diclo behaved as a competitive inhibitor, but it was not transported into cells, whereas its analogue AA-NH-Diclo showed a decreased inhibitory activity. Stability studies suggest AA-Diclo as a potential candidate to enhance the Diclo short half life in vivo. The discovery of a Na+-dependent transporter for Diclo on HRPE cells opens new perspectives for targeting diclofenac into the brain. (C) 2004 Elsevier B.V. All rights reserved.