Recently, I got to participate in the 11th annual Orlando Dermatology Aesthetic and Clinical Conference (ODAC for short). I’m usually not a big fan of conferences, never really getting anything out of them before, but this was a great experience. Other than enjoying the sun in a city where it is appropriate to wear spring clothing in the dead of winter (location, location, location), I had a poster to present, I met some new people and I learned A LOT. In medical school, if you’re interested in dermatology, you’re a little out of luck when it comes to pre-clinical training. It’s basically a dog-eat-dog world out there, and if you want to learn dermatology, you better go seek it out yourself. So, this conference was a welcome change.
As the title implies, there is a heavy emphasis on “aesthetics”, especially cosmeceuticals. One of the most interesting things in the conference, at least to me, was a short 15 minute presentation provided by Aveeno in which a scientist from the company demonstrated how to make a five-minute lotion with a KitchenAid immersion blender (I kid you not), and that got me really interested. With the dawn of the age of the “physician’s own brand” of skin care, it has become quite obvious to me that the knowledge needed to make a line of cosmeceuticals might be very useful for the budding physician.
Basically any lotion is an emulsion, a highly suspended mixture of water and oil with a “binder” (i.e. the emulsifier) playing the mediator. Usually water and oil don’t mix. Just imagine a vinaigrette where the olive oil (“oil phase”) separates from the vinegar (“water phase”); however, add an egg yolk to the vinaigrette, mix vigorously with a whisk until your arm falls off and then you have the base for a Caesar salad dressing. The egg proteins acted as an emulsifier because the properties of the proteins are such that they can interact with both water and fat allowing them to meld into one mixture. So lotion is the exact same thing; in it’s simplest form the “water phase” is just water and the “oil phase” consists of an oil (typically plant-based) and glycerin (the emulsifier). Mix them together vigorously for about five minutes and let it stand for another thirty and you have a nice, thick mixture.
But of course, your run-of-the-mill lotion isn’t this simple. Even the simplest lotion found will have a laundry list of ingredients. So what does it all mean? In each of the phases, it is possible to add a bunch of different ingredients that enhance the product (either make the lotion feel better, smell nicer or have medical properties against a skin “disease” state like eczema, dryness, sun damage etc.). In the water phase it is possible to add humectants (products that hold onto moisture and can be used to control the viscosity of the cosmetic), chelators (products that soak up dicationic metals thus enhancing preservation by not allowing microbes to grow), thickeners or stabalizers (products that stabalize the product). In the oil phase, one can add emollients (esters, fatty alcohols, waxes, silicones and occlusive agents to improve the skin feel) or co-emulsifiers (chemicals to increase the viscosity). After the water and oil phases have been mixed (in the consumer world the thousands of pounds of mixture are usually heated and super-cooled to ensure that the proper cosmetic “feel”), then the preservatives (to ensure no microbial growth even under contamination), fragrance, active botanicals, antioxidants, colorants and pH adjusters are added. These ingredients are usually added last because they are heat-labile (meaning they would be destroyed in the heating process after the water and oil phases are mixed).
So, in fact, what seems very complicated at first, comes down to the principles of chemistry, especially organic chemistry (something practical may emerge from my undergraduate training yet!). There are many real-world applications to the concepts we learn as young scientists before entering medical school, and this is a great way to put it to use. The real science comes down to knowing what supplementary ingredients will make the product suited for a certain type of skin, make the product feel nicer, and make the product have a pleasing smell, among other things. Maybe ten years in the future, look for a Juhasz-branded skin product line!
Margit Lai Wun Juhasz
Mount Sinai Medical Student