Methyltestosterone (MT) is a steroid widely used in animal production techniques, especially in aquaculture. A combination of MT and cyclodextrin can cause changes in the physicochemical and steroid release profile, providing a desirable effect with relatively low doses. In this study, inclusion complexes between MT and γ-cyclodextrin (γ-CD) were prepared and characterized in solution and solid phases. The use of γ-CD enhanced the apparent solubility of the steroid by 17-fold, and the inclusion complex formed exhibited 1:1 stoichiometry. The association constant (Ka) was determined under two distinct solvent conditions: 26,600 L mol-1 by solubility isotherm in water, and a lower value of 10,970 L mol-1 by DOSY-NMR using a DMSO‑d6/D2O mixture, highlighting the impact of the solvent environment on complex stability.
The results demonstrated the complexation of MT in γ-CD is very promising for future applications involving this steroid in aquaculture, both for sex reversal and in-water hormone sequestration technologies.
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Lucas Bragança Carvalho, Carlos Jaime, Tiago Venâncio, Leonardo Fernandes Fraceto, Luciana Matos Alves Pinto (2025) Inclusion complex of γ-cyclodextrin and methyltestosterone for fish sex reversal: Release and characterization studies. Journal of Molecular Structure 1347, 143302.
https://doi.org/10.1016/j.molstruc.2025.143302.
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