The science of emulsion formulation has, in recent years (15 years is still considered recent to me!), taken great leaps forward as we have begun to increase our understanding of the mechanisms, on the micro level, that are responsible for producing stable emulsions.
We must remember, of course, that all emulsions we cosmetic chemists create (forgetting about spontaneously forming microemulsions) are thermodynamically unstable and will, some day, exhibit signs of emulsion instability. Hopefully, that day will be after the emulsion is sold and used by the consumer.
Excerpt Only This is a shortened version or summary of the article that appeared in the May 1, 2002 issue of Cosmetics & Toiletries magazine. The full content is not currently available online.