Investigation of Adsorption of the Cardiotonic Drug Milrinone Onto Montmorillonite: An FTIR and Raman Spectroscopic Study
Sevim AkyüzMilrinone is a cardiotonic drug that is used for the treatment of congestive heart failure. Clay minerals are widely used materials as a low-cost nanocarriers in designing drug delivery systems. Drug-clay interaction is important since it affects drug action. Montmorillonite, a clay mineral with high adsorption and swelling properties, is useful as a low-cost nanocarrier in deisgning drug delivery systems. The adsorption of a molecule on a clay surface, or formation of intercalates, gives rise to changes in the vibrational wavenumbers of the adsorbed molecule. In this study, interaction between the adsorbed milrinone molecules and montmorillonite was investigated by FT-IR and Raman spectrometry. The X-ray diffraction patterns of montmorillonite before and after treatment with milrinone showed a significant change in the d(001) reflectance of clay. This reflection peak shifted to a lower angle due to the adsorption of milrinone onto the clay. The result indicated the intercalation of the milrinone molecules by increasing the interlayer spacing of the clay. Vibrational spectroscopic results indicated that intercalated milrinone interacted with clay by direct or indirect coordination (through water molecules) to exchangeable cations or the Lewis acidic centers.
