Release behavior of cupric ions for TCu380A and TCu220C IUDs.

We immersed copper T380A and T220C IUDs in simulated uterine solution (SUS) and also in simulated body fluid (SBF). The release rate and corrosion products of copper ions after soaking in SUS and SBF for different time spans were studied by an atomic absorption spectrophotometer, scanning electron microscopy with energy dispersive x-ray microanalysis (SEM/EDX) and x-ray diffraction. The highest corrosion rate of the TCu380A IUD was obtained on the first day, while the highest corrosion rate of the TCu220C IUD was obtained on the third day. The copper corrosion rate of the TCu380A IUD was much faster than that of the TCu220C IUD in the first few days. The corrosion extent of copper wire was higher than that of a copper tube when first immersed in solution. For the same IUD in the same solution, the corrosion extent in SBF was higher than in SUS. The main compounds identified were cuprite (Cu(2)O). Copper wire and copper tubes were implanted in the uteruses of rats. In vivo experiments were also done. The corrosion rate in vivo was higher than that in vitro.