Solubilizing steroidal drugs by β-cyclodextrin derivatives.

Area of Science:

• Pharmaceutical Sciences
• Supramolecular Chemistry

Background:

• Steroidal drugs exhibit poor water solubility, limiting their administration and bioavailability.
• Beta-cyclodextrin (β-CD) and its derivatives are known to improve the solubility of hydrophobic active pharmaceutical ingredients (APIs).

Purpose of the Study:

• To systematically review solubility enhancements of various steroids using β-CD derivatives.
• To investigate the role of cyclodextrin structure and substituents in steroid solubilization.

Main Methods:

• Systematic review of literature on steroid-cyclodextrin complexation.
• Analysis of factors influencing solubility enhancement, including steric fit and cyclodextrin substituents.
• Characterization of binding interactions using ROESY NMR spectroscopy.

Main Results:

• Anionic heptakis-6-sulfoethylsulfanyl-6-deoxy-β-cyclodextrin (HSES) achieved 60-90% complexation efficiency for most tested steroids.
• Neutral β-CD thioethers, heptakis-6-methylsulfanyl-6-deoxy-2-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)]-β-CD (HTMT) and heptakis-6-thioglyceryl-6-deoxy-β-CD (HTG), exhibited gender selectivity for testosterone and estradiol, respectively.
• Solubilization primarily involves complexation of the A/B and C/D rings of the steroid framework.

Conclusions:

• β-CD derivatives are effective in enhancing steroid solubility and bioavailability.
• HSES is a highly efficient solubilizing agent for a broad range of steroids.
• Specific β-CD thioethers demonstrate selective binding for hormonal steroids, suggesting potential for targeted drug delivery.