Bioavailability of phytochemicals and its enhancement by drug delivery systems

Issues of poor oral bioavailability of cancer chemopreventives have hindered progress in cancer prevention. Novel delivery systems that modulate the pharmacokinetics of existing drugs, such as nanoparticles, cyclodextrins, niosomes, liposomes and implants, could be used to enhance the delivery of chemopreventive agents to target sites. The development of new approaches in prevention and treatment of cancer could encompass new delivery systems for approved and newly investigated compounds. In this review, we discuss some of the delivery approaches that have already made an impact by either delivering a drug to target tissue or increasing its bioavailability by many fold.

► Drug delivery systems can overcome poor bioavailability of chemopreventives.
► Chemopreventives should be tagged to the target organ where they bioaccumulate.
► Chemopreventives should preferably be non-nutrient phytochemical to avoid imbalance in micronutrient metabolism.
► Chemopreventives as adjuvant treatment to traditional chemotherapies will establish their true potential in clinical settings.