Cyclodextrin-poly(anhydride) nanoparticles as new vehicles for oral drug delivery

The oral administration of drugs belonging to Class IV of the Biopharmaceutical Classification System (BCS) represents a major challenge. These drugs display poor aqueous solubility and specific permeability characteristics. Most of these compounds are substrates of the P-glycoprotein and/or the cytochrome P450. Among other types of drug, various anti-cancer drugs also suffer from these drawbacks (i.e., paclitaxel), which limits the possibilities for developing oral treatments.

This review discusses the factors that influence the bioavailability of drugs when administered by the oral route, as well as the capabilities of cyclodextrins when associated with nanoparticles. In particular, evidence is given regarding the synergistic effect between cyclodextrins and bioadhesive nanoparticles, on the oral delivery of pharmaceuticals.

This article aims to provide an overview of the multiple gains in incorporating cyclodextrins in poly(anhydride) nanoparticles, including improvement of their bioadhesive capability, the loading of lipophilic drugs and the effect on efflux membrane proteins and cytochrome P450. The combination between bioadhesive nanoparticles and P-gp inhibitors without pharmacological activity (i.e., cyclodextrins) may be useful to promote the oral bioavailability of drugs ascribed to Class IV of the BCS.