Exploring the possibility of predicting long-term oxidative stability in prototype skincare formulations using various lipid oxidation initiators.

Objective: The purpose of this study was to identify an effective lipid oxidation initiator which could predict, within 1 month, the long-term oxidative stability of a prototype skincare formulation. The main purpose was to find a potential initiator not to assess oxidation stability of the formulations.

Methods: Four initiators (below) were examined in three steps: Reaction kinetics using a Clark electrode (Oxygraph); Effect of adding an initiator on the product's physical and oxidative stability in prototype skincare formulations by visual observation, peroxide value and headspace GC-MS determination of volatile oxidation products; and Ability to differentiate unstable vs.