Induced surface activity of supramolecular cyclodextrin–statin complexes: Relevance in drug delivery

Complexation of active therapeutic agents with cyclodextrins (CDs) offers potential uses in pharmaceutical and biomedical applications for controlling drug delivery and targeting. This paper reports on possible enhancement of the aqueous solubility and bioavailability of sparingly soluble statins (simvastatin and lovastatin) by inclusion complexation with native β-cyclodextrin and a chemically modified β-cyclodextrin, respectively. Complexation-induced surface activity of the supramolecular associates and the effect of the pure CDs and the amphiphilic CD–statin complexes on the physical stability of colloidal liposomes of dipalmitoyl phosphatidyl choline (DPPC) are discussed.It was shown that complexation with either cyclodextrin may lead to considerable improvement of the aqueous solubilities of both statins. Randomly methylated β-cyclodextrin (RAMEB) showed particularly outstanding solubilizing effects.The cyclodextrin molecules dissolved in the medium of liposome dispersions strongly reduced the physical stability of the phospholipid membranes. Complexation of the hydrophobic DPPC chains with cyclodextrins may ultimately lead to disintegration of the vesicles. In ternary systems, where due to the complexation of the pharmacon with the cyclodextrin amphiphilic CD–statin associates could develop, an enhanced and prolonged physical stability of the vesicles could be ensured.