The aim of the present work was to improve the physicochemical properties of Gem through cyclodextrin (-CD) or hydroxypropyl-cyclodextrin (HP-CD) interactions. Gemfibrozil water solubility and dissolution rate were increased by cyclodextrin complexation. The study has shown that complex formation, in 1:1 stoichiometric ratio,
was successfully obtained in aqueous solution while in
the solid state only very small interactions between drug and different cyclodextrins were revealed. The pH value, changing the ionization degree of drug molecule, influenced the complexation process, as indicated by different stability constant values obtained at various pH.
