Application of diethylene glycol monoethyl ether in solubilization of poorly water-soluble drugs

Background: Diethylene glycol monoethyl ether (DEGEE) is produced via the O-alkylation of ethanol with two ethylene oxide units, followed by distillation. It has a long history of safe use in food and personal-care products, and is used as an effective strong solubilizer in oral, topical, transdermal, and injectable human and veterinary pharmaceutical products. It has been used as a pharmaceutical solvent for many years under the trade name transcutol. DEGEE, a hydroalcoholic solvent, is gaining interest as a penetration/permeation enhancer, solubilizer, and surfactant for drug delivery systems. Area covered: The physicochemical properties of DEGEE, the solubility data for drugs in DEGEE or DEGEE-water mixtures, and the applications of DEGEE in the solubilization of poorly water-soluble drugs are summarized in this review. Expert opinion: DEGEE is a promising excipient as a solubilizer for many pharmaceutical products with enhanced drug absorption via oral, parenteral, and topical administration, as well as cosmetic products.