کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5547987 | 1556153 | 2017 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Complex formation equilibria of Cu2 + and Zn2 + with Irbesartan and Losartan Complex formation equilibria of Cu2 + and Zn2 + with Irbesartan and Losartan](/preview/png/5547987.png)
We conducted a thorough study of Cu2Â + complex formation equilibria with Irbesartan and Losartan, the two primary drugs for the cure of cardiovascular diseases, with the aim of recognising if these drugs could exert a chelating action towards Cu2Â +. We used different complementary techniques to gain a clear picture of the involved protonation and complexation equilibria. The low solubility in water of the ligands and of the formed metal complexes prevented the use of water as solvent, so we had to perform the measurements in mixed methanol-water solvents. Further, we studied the related equilibria with Zn2Â + for evaluating a potential interference of this essential metal ion, largely present in biological fluids. Our study provided a strong evaluation of the formed complexes and of the relative stability constants. The binding of both metal ions takes place through the tetrazole moiety except for the Zn2Â +-Irbesartan system. In this last case, NMR measurements gave evidence of a tautomeric equilibrium involving the imidazole ring and the aliphatic chain. The estimated complexation model, and the related stability constants, allowed a speciation study in human plasma, based on a number of simplifying assumptions, which remarked that both drugs, Losartan and Irbesartan, could exert a chelating action, scavenging non-negligible amounts of Cu2Â + from the organism.
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Journal: European Journal of Pharmaceutical Sciences - Volume 97, 15 January 2017, Pages 158-169