Polyoxyethylene 20 oleyl ether brij 98

Pure chemical DEET was purchased from Fluka Chemika GmbH (Buchs, Switzerland), and OBZ was purchased from Riedel Haer GmbH (Seelze, Germany). Some of the emulsion ingredients, Emulfree CBG (butylene glycol cocoate, ethyl cellulose, and isostearic alcohol), Labrasol (caprylocaproyl macrogolglycerides), Geleol (glyceryl monostearate 40–55), Isostearate isostearyle, Labrafac PG (propylene glycol dicaprylocaprate), and Plurol Oleique CC 497 (polyglyceryl oleate), were kindly supplied by Gattefossé Canada, Inc. (Toronto, ON, Canada). Cetyl alcohol and xanthan gum were obtained from Medisca Pharmaceutique Inc. (Montreal, QC, Canada). Glycerin and mineral oil were purchased from Mallinckrodt Specialty Chemical Company (Paris, KY, USA). Acetonitrile, glacial acetic acid, potassium phosphate monobasic, sodium hydroxide, and castor oil were purchased from Fisher Scientific (Fair Lawn, NJ, USA). Polyoxyethylene 20-oleyl ether (Brij^® 98) was obtained from Sigma Chemical Co. (St. Louis, MO, USA). Arlacel P135 was supplied by UNIQEMA (New Castle, DE, USA). Cabomer 934 was obtained from BF Goodrich Company, Chemical Group (Cleveland, OH, USA). Low-density polyethylene (LDPE) membrane was supplied by Key Container (Winnipeg, MB, Canada).