Pluronic® block copolymers as modulators of drug efflux transporter activity in the blood–brain barrier

Drug efflux transporters can influence the absorption, tissue distribution and elimination of many therapeutic agents. Modulation of drug efflux transporter activity is being explored as a means for improving the pharmacokinetic and pharmacodynamic properties of various drugs. In this regard, several polymer formulations have been shown to inhibit drug efflux transporters such as P-glycoprotein (P-gp). The current review will focus on Pluronic® block copolymers in particular, the mechanisms involved in the effects of Pluronic® on drug efflux transporters, and the optimal polymer compositions required for inhibition of drug efflux transporters. Special emphasis will be placed on the potential applications of Pluronic® in enhancing the blood–brain barrier (BBB) penetration of drugs.