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 rules)
The thesis, which was administered by the researcher (Nabil Ali Odeh), included
The current study prepared 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.
The effect of the formation of implicit complexes on the solubility of the Schiff bases was also studied using the method of (Conner) and (Higuchi, where the results showed that the solubility increases by (3-9) times when the complexes are formed, and the stability constants Kc were calculated, which confirm that the formed complexes are in a ratio of 1:1.
The study concluded
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.
Recommendations:
The drugs used in the preparation of Schiff bases are used as antibacterial and antibacterial, and their solubility is low in water, which limits their use as a therapeutic agent and their bioavailability, so they were complexed with beta and alpha dextrin and became water soluble, so it was suggested that other types of low solubility drugs be used to improve their solubility. Studying the relase release rate of the complexes produced in aqueous solutions and comparing them with free bases.