D-α-tocopheryl polyethylene glycol succinate (Vitamin E TPGS, or simply TPGS) is a water-soluble derivative of natural Vitamin E, formed by esterification of Vitamin E succinate with polyethylene glycol (PEG).

It has the advantages of PEG and Vitamin E in applying various nanocarriers for drug delivery, including extending the drug’s half-life in plasma and enhancing the cellular uptake of the drug. TPGS has an amphiphilic structure of lipophilic alkyl tail and hydrophilic polar head with a hydrophile/lipophile balance (HLB) value of 13.2 and a relatively low critical micelle concentration (CMC) of 0.02% w/w, which make it to be an ideal molecular biomaterial in developing various drug delivery systems