The stabilization of parenteral fat emulsion using non-ionic ABA copolymer surfactant

Abstract

The effect of autoclaving on the stability of emulsions with different oil phases and different non-ionic surfactants was evaluated in order to develop a stable formulation. The effect of heating on the physicochemical properties during the autoclaving was determined by the changes in the emulsion droplet size. It was found that a combination of non-ionic copolymer surfactant (F68) with an oil phase mixture consisting of castor oil with either soybean oil or middle-chain triglycerides (MCT) 1:1 w/w yielded fine emulsions with particle sizes ranging from 120 to 140 nm. These emulsions did not show significant changes in their droplet sizes upon autoclaving and showed a good stability both in the presence of Ca 2+ ions and at different pH values (5–9). In contrast to F68, emulsions prepared using other non-ionic emulsifiers as PEG-sorbitan monooleate (Tween 80), polyoxyethylene-660-hydroxystearate (Solutol H15) and polyoxyethylene-35-ricinoleate (Cremophor EL) showed an increase in droplet size upon autoclaving. The results could be explained on the basis of high cloud point of F68 resulting in more resistance against dehydration during autoclaving and subsequently no emulsifier damage. Due to the influence of castor oil on the interfacial tension it can act additionally as a co-surfactant. These factors avoid the flocculation of the emulsifier and can hinder the coalescence of the oil droplets during the autoclaving process.