Study of the complexation of the stress hormone with (2-hydroxypropyl) α-, β- and γ-cyclodextrins in aqueous solution

In the present work, the interactions between hydrocortisone (11,17,21-trihydroxypregn-4-ene-3,20-dione, HC; stress hormone) and cyclodextrins were investigated. The cyclodextrins selected for this study were (2-hydroxypropyl)-α-cyclodextrin (2-HP-α-CD), (2-hydroxypropyl)-β-cyclodextrin (2-HP-β-CD) and (2-hydroxypropyl)-γ-cyclodextrin (2-HP-γ-CD). The study was carried out using density measurements, ¹H-NMR and FT-IR spectroscopy. Preliminary studies show that (2-hydroxypropyl)-α-cyclodextrin has a low affinity for hydrocortisone (HC), while (2-hydroxypropyl)-β-cyclodextrin and (2-hydroxypropyl)-γ-cyclodextrin have a good affinity for hydrocortisone in both solid state and solution. The study was carried out at two temperatures: 298.15 K and 310.15 K. The results suggest that at both temperatures, the system 2-HP-β-CD + HC induces an increase in the solvent structure, with increasing the solute concentration in the solution, while on the contrary the system 2-HP-γ-CD + HC induces a decrease in the solvent structure when the concentration of the solute in the system increases.