Interaction between indomethacin and heavy metal ions in aqueous solution

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Indomethacin is a nonsteroidal anti-inflammatory drug.
• Heavy metal ions are environmental pollutants and can interact with organic molecules.

Purpose of the Study:

• To investigate the complexation interactions between indomethacin anions and heavy metal ions (Cd, Zn, Cu(II)).
• To characterize the solubility and stability of the formed complexes.
• To explore the effect of indomethacin self-aggregation on complex solubility.

Main Methods:

• Polarographic techniques were employed to study the interactions in aqueous solutions.
• Solubility of complexes was assessed.
• Complex formation in the presence of calcium ions was also investigated.

Main Results:

• Indomethacin anions form complexes with cadmium, zinc, and copper(II) ions.
• The cadmium-indomethacin complex is sparingly soluble.
• Zinc and copper(II) form more soluble and stronger complexes with indomethacin.
• Indomethacin self-aggregation at high concentrations leads to solubilization of zinc and copper(II) complexes.
• Indomethacin forms a poorly soluble salt with calcium ions, with no evidence of complexation.

Conclusions:

• Indomethacin exhibits varying complexation behavior with different heavy metal ions.
• Solubility of indomethacin-metal complexes is influenced by the specific metal ion and indomethacin concentration.
• The findings provide insights into the chemical interactions relevant to drug formulation and environmental chemistry.