Vitamin-E TPGS Based Microemulsion: An Approach for Solubility Enhancement of Poorly Water-Soluble Drugs

Poor aqueous solubility is the primary concern for dissolving new drug substances during early development. Several novel solubility enhancement techniques such as particle size reduction, salt formation, making solid dispersion, complex formation, use of cosolvent techniques, use of surfactants, physical and chemical modification, and PH adjustment using buffering agents have been explored extensively to resolve the issue of poor aqueous solubility of drug substances. Drug delivery in micro and nano-sized formulations is one of the ways to improve the solubility of these drug candidates over the physiological pH range. In recent years, combination methods have also been considered an interesting approach where more than one solubility enhancement technique is used. The present review focuses on the feasible approach for improving the solubility by forming Vitamin E TPGS-based suspension in micro or nano form by particle size reduction. Further, by granulation or spray drying techniques, these suspensions converted to a solid dosage form for oral drug delivery for patient compliance are being explore