D-tocopheryl polyethylene glycol succinate (Vitamin E TPGS) has been approved as a safe pharmaceutical adjuvant by FDA, and several drug delivery systems (DDS) based on TPGS have been developed. TPGS properties as a P-gp inhibitor, solubilizer/absorption and permeation enhancer in drug delivery and TPGS-related formulations such as nanocrystals, nanosuspensions, tablets/solid dispersions, vaccine system adjuvant, nutritional supplement, film plasticizer, anticancer reagent, and so on, are discussed in this review. Consequenly, TPGS can inhibit ATP-dependent P-glycoprotein activity and act as a potent excipient that promotes the efficiency of delivery and the therapeutic effect of drugs. Inhibition of P-gp occurs through mitochondria-dependent inhibition of the P-gp pump. Many of the latest studies address the use of TPGS for many poorly water-soluble or permeable drugs in the manufacture of nanodrugs or other formulations. In addition, it has been reported that TPGS shows a robust improvement in chylomicron secretion at low concentrations and improves intestinal lymphatic transport, which would also boost the potential of drug absorption. It also indicates that there are still many problems facing clinical translation of TPGS-based nanomedicines, requiring a more deep evaluation of TPGS properties and a future-based delivery method.
Preparation and characterization of Alendronate depot microspheres based on novel poly(-ε-caprolactone)/Vitamin E TPGS copolymers
