Zinc-naproxen complex: synthesis, physicochemical and biological evaluation.

Naproxen has a propensity to cause ulcers whereas zinc ions are known to possess an anti-ulcer and anti-inflammatory activity. Therefore, zinc complex of naproxen was prepared by adding zinc sulfate to an aqueous solution of sodium naproxen and its structure was characterized by IR, 1H NMR and 13C NMR, UV, DSC, atomic absorption spectroscopy, and elemental analysis. Anti-inflammatory studies, using the carrageenan-induced hind paw oedema showed that there was a significant difference (P<0.05, ANOVA plotted by Dunnet's test) in the anti-inflammatory activity of naproxen, its zinc complex, and the physical mixture of naproxen and zinc sulfate. In addition, zinc complex of naproxen showed a significant reduction in ulcers (lesion index (LI)) as compared to that of naproxen and physical mixture of naproxen and zinc sulfate. Thus, the use of the complex may be preferable to naproxen alone.