Required HLB Determination of Some Pharmaceutical Oils in Submicron Emulsions

Abstract

Different calculations of the hydrophilie-lipophilie balance (HLB) value of Sorbitan fatty acid ester are discussed in literature. Influence on the required HLB value of ethyl oleate was investigated using several emulsifier blends: Span 80/Tween 20, Oleth-3/Steareth-20, Oleth-5/Steareth-20, Oleth-3/PEG-40-Stearate. The calculations of the HLB value of Span 80 have a bearing influence on the determination of the required HLB value. The postulated transferability of the determined required HLB value by the Tween 20/Span 80 system compared to other emulsifier systems is depending on the used equation. Additionally, the required HLB values of the pharmaceutical oils coco-caprate/caprylate and cetearyl isononanoate were determined empirically by preparing submicron emulsions.