Passive and active targeting strategies for the delivery of the camptothecin anticancer drug: a review

Cancer is the second highest cause of death globally, with about 70% of deaths occurring in low- or middle-income countries, thus calling for efficient cures. Nanotechnology research has evidenced numerous therapeutic innovations that target the tumor tissues either passively or actively. Camptothecin is a potent anticancer drug which has shown appreciable antitumor activity against a broad spectrum of cancers such as breast, ovarian, colon, lung and stomach. Nonetheless, applications of camptothecin are limited by water insolubility, rapid conversion of its bioactive lactone form to inactive carboxylate under physiological conditions, drug resistance and off-target side effects. Here, we review the delivery of camptothecin by active and passive targeting for anticancer activity. We discuss the mechanism of action and the novel targeted drug delivery platforms that have been explored for the delivery of camptothecin for the treatment of solid tumors.