The College of Education for Pure Sciences at the University of Basrah in the Department of Chemistry discussed a master's thesis on preparation and study of the physical properties of some implicit complexes of Schiff bases.
The thesis, which was administered by the researcher (Nabil Ali Odeh), included preparing two Schiff bases derived from the interaction of para-dimethylaminobenzaldehyde with each of sulfaproxylene and sulfamethazine, which are characterized by their low solubility in water and the study of the effect of the formation of implicit complexes with cyclodextrins on improving the physical properties of the prepared Schiff bases. The intrinsic complexes were prepared by freeze drying method.
The nature of the interference between the free bases and their complexes was diagnosed using a comparative study using IR 1H-NMR spectroscopy, UV-visible spectroscopy, and scanning electron microscopy, (SEM), where the electron microscope images showed a clear difference in the shape of the surfaces of the Schiff bases and their complexes, including the distribution of the Practical Size of the particles and the diameters of the bases and their complexes.
Also, the effect of the formation of implicit complexes on the solubility of the Schiff bases was studied using the method of (Conner) and (Higuchi), where the results showed that the solubility increases once the complexes are formed, and the stability constants were calculated, which confirm that the formed complexes are in a ratio of 1:1.
The study concluded that:
-All techniques that were used clearly confirm the formation of stable intrinsic complexes at a ratio of 1:1 between Schiff bases derived from sulfa drugs and cyclodextrins by (freeze-drying) method using deionized water.
-The solubility of Schiff bases, which are very poorly soluble in water, as well as sulfa drugs, can be improved by converting them into complexes implicit with cyclodextrins, and this was confirmed by the solubility phase data.
