Radiant, youthful-looking skin starts with vitamin A and continues with vitamin C. Topically applied L-ascorbic acid, if stabilized and delivered properly, fights free radical damage, increases production of collagen and reverses age-related changes in the interface between the dermis and the epidermis.
Vitamin C is a formulator’s nightmare because it is extremely unstable—exposures to air, heat and/or light degrade it, and of course, it oxidizes very rapidly in water. The antioxidant properties that make it so desirable to use as a skincare ingredient are the very properties that make it so difficult to work with. Over the years skin-care researchers have sought answers, but their solutions have been far from perfect. They include:
Synthetic derivatives: Stable synthetic derivatives like ascorbate phosphate and ascorbyl palmitate, aka ester-C, have limited permeability and function in the skin. They just don’t compare to natural L-ascorbic acid, the least stable in solution.
L-ascorbic acid kept separate until ready to use. The problem here is devising a way to store the powder that minimizes its exposure to light, heat, air and moisture. Vitamin C stored in capsules or ampoules are poor choices because of the exposure to oxidative elements during manufacture, and again while in storage. Vitamin C stored in opaque containers that can be sprinkled over a serum or cream are a better solution, but one that still leaves vitamin C vulnerable to some degradation, both during production and while in storage. In addition, when the ascorbic acid is dissolved in water just prior to use it may irritate skin, since irritation, if it occurs, is caused mainly by the generation of hydrogen ions when the acid dissociates in water.
Fortunately, we have, as always, research and development to the rescue. Since water is the main catalyst of vitamin C oxidation, it makes sense that stabilization could be achieved by using an anhydrous (containing no water) vehicle. Indeed, anhydrous vitamin C is not only more stable in storage but also on the skin after application. (To learn more about description of the non-aqueous vehicle’s ingenious design, please follow the discussion of vitamin C in our December “From the Lab” section.)
Stability: Vitamin C remains stable in suspension until it is delivered to the skin. And it is protected right up to the time it is put on the skin and the organic solvent evaporates. There is no exposure of the L-ascorbic acid to elements that may degrade it.
No irritation: Anhydrous vitamin C is less irritating than ascorbic acid dissolved in water just prior to use because irritation is caused mainly by the hydrogen ions generated by the acid dissociating in water. Effective penetration: Evidence indicates that ultrafine microcrystalline vitamin C in an anhydrous vehicle can stimulate collagen synthesis. In a 2006 study published in the Journal of Cosmetic Dermatology, Dr. Geoffrey K. Heber and coworkers studied the effects of 20-23% ultrafine microcrystalline anhydrous vitamin C on the collagen synthesis in the sections of human skin and found increased production of both type I and type III collagen. This implies that this form of topical vitamin C has the ability to penetrate to deeper skin structures.
This ingenious invention gives skin-care formulators the opportunity to create truly effective age-defying products. If you want the best in skin care, I highly recommend searching out products that contain stabilized L-ascorbic acid.
Have a question about our blog content and how it may apply to your own skin concerns? Email us here to get personalized advice from our on-call estheticians, or browse our Product Recommendations here.