Emulsifiers are great for keeping mixtures of oil and water together but they do have a number of downsides that has prompted researchers to look for alternatives. Some of the problems include skin irritation, questionable stability, cost, environmental problems, regulatory issues and difficulties in production. There are a few options you can try to remove your emulsifier from your formula. These technologies are relatively new and haven’t taken over the industry but this may represent the future of emulsification in cosmetics.
Polymeric emulsions – The basic idea in a polymeric emulsion is that the polymer is able to tie up a number of different particles so an emulsion can be created. But since polymers are such large molecules they are not able to penetrate the skin and cause any of the problems typically associated with emulsifiers. Hydroxypropyl Methylcellulose or Acrylic Acid polymers like Carbomer can be used to create these emulsions. I expect polymeric emulsions will eventually take over in the cosmetic industry since they are easy to use, highly stable, and can be done via cold processing.
Acoustic emulsification – If you don’t want to use a chemical method for creating an emulsion you might try a physical method. Acoustic emulsification is a method by which you mix water and oil then use ultrasound to break up the immiscible particles into particles that are so small that they stay suspended in the solution. Thus you have a stable mixture of oil and water without an emulsifier.
Shake before use – Of course, you can also make a formulation that is a mixture of water and oil but requires the user to shake the product before using it. Mechanical mixing like this can lead to short term stability which may be just long enough for your purposes. This is a rather crude method of formulating but it will work in some cases. The oil and water phases just have to have some level of compatibility. You can get this by using an oil that has a high HLB.
Have you used any of these methods? Leave a comment below and tell us about it.