**2. Materials and Methods**

Cold pressed flaxseed, soybean, sunflower, olive, grapeseed and macadamia oils were purchased from Escentia products (Johannesburg, Gauteng, South Africa). Span® 20 and Tween® 80 were purchased from Merck (Johannesburg, Gauteng, South Africa). HPLC grade acetonitrile from Burdick and Jackson™ and ethanol were purchased from Anatech (Olivedale, Gauteng, South Africa). EFV (Form 1) was donated by Adcock Ingram® Limited (Wadeville, Gauteng, South Africa). HPLC-grade water was produced using a RephiLe Bioscience Direct-Pure® Ultrapure RO Water system, (Boston, MA, USA). 600 mg EFV tablets produced by Adcock Ingram Limited (Midrand, South Africa), Cipla Medpro (Cape Town, South Africa), Aspen Pharmacare Limited (Port Elizabeth, Eastern Cape, South Africa) and Aurobindo Pharma Limited (Alberton, South Africa) were purchased from a local pharmacy. Unless otherwise indicated, all materials were at least of analytical grade and were used without further purification.
