In vitro enhancement of anticancer activity of paclitaxel by a Cremophor free cyclodextrin-based nanosponge formulation

A severe limitation for cancer therapy is the poor water solubility of many important therapeutic anticancer drugs. The development of novel delivery systems is therefore currently ongoing. We propose the use of beta-cyclodextrin based nanosponges to deliver paclitaxel as an alternative to classical formulation in Cremophor EL. They are solid nanoparticles with mean diameter lower than 500 nm and spherical shape. Nanosponges show a safe profile being non-hemolytic and non cytotoxic. Nanosponges dissolved and encapsulated paclitaxel up to 2 mg/ml. The paclitaxel-loaded nanosponges formed a water stable colloidal system avoiding the recrystallization of paclitaxel. The in vitro release studies showed an almost complete release in 2 h without initial burst effect. Our study demonstrates that delivery of paclitaxel via nanosponges increased the amount of paclitaxel entering cancer cells and lowers paclitaxel IC50, therefore enhancing its pharmacological effect. beta-Cyclodextrin based nanosponges can therefore be considered an alternative system to solubilize and deliver the paclitaxel.