Delivery systems for vorinostat in cancer treatment: An updated review

Vorinostat is a histone deacetylase inhibitor that has received regulatory approval for the treatment of advanced and refractory cutaneous T-cell lymphoma. In contrast to the encouraging clinical results obtained on hematologic tumors, only limited clinical efficacy was observed in solid tumors following administration of vorinostat alone. Moreover, vorinostat is poorly soluble, poorly permeable, and extensively metabolized in the liver, rendering its bioavailability too low to exhibit sufficient antitumor effects. This review aims to provide some insight into successful formulation strategies that use physical encapsulation and chemical conjugation to improve the characteristics and achieve better antitumor activity from vorinostat alone or in combination with other therapeutic compounds and/or modalities.