For the protection of the skin, vitamin C is one of the most common active ingredients. Unfortunately, conventional vitamin C is not particularly stable in cosmetic formulations. Moreover, due to its high chemical activity, it is already metabolized in the outermost layer of the skin.
 
The beige-colored, powdery sodium ascorbyl phosphate, on the other hand, is a stable, water-soluble vitamin C derivative that also penetrates into deeper skin layers. There, the skin's own enzymes release the actual active ingredient - vitamin C - from the sodium ascorbyl phosphate. Vitamin C can thus develop its effect extremely effectively. One of its most outstanding properties is its ability to intercept free radicals, or reactive oxygen species, and render them harmless. This is particularly evident in light-induced (or environmentally-induced) skin aging. UVA radiation in particular causes premature aging of the skin through the formation of free radicals and subsequent activation of collagen-degrading enzymes. In addition, vitamin C stimulates collagen formation, which in turn affects the regeneration of the skin barrier, promotion of skin elasticity, reduction of moisture loss, and finally the reduction of fine wrinkles. Since vitamin C also inhibits or reduces the activity of the enzyme tyrosinase and thus the formation of melanin, it can also be used in skin-lightening formulations (e.g. against age spots). Since it also acts against sweat-causing and acne-causing bacteria, it is also recommended for deodorant formulations and treatment of skin blemishes and acne.
 
Application concentration:
daily skin/sun care: 0.2 - 2.0%.
skin whitening: min. 3,0 - 5,0 %
deodorant: 0,2 %
Acne: 5,0 %
 
Processing: 
Sodium ascorbyl phosphate is sensitive to heat, low pH, and heavy metals. Dissolve sodium ascorbyl phosphate in a little water before incorporating it into a cooled emulsion below 40 °C! Finished formulations should be stored below 25 °C. Commercial formulations should be adjusted to a pH value of at least 6.5. The addition of a complexing agent, e.g. phytic acid, is also recommended here.
 
Self-stirrers who use their formulations within approx. 3 - 6 months after manufacture can also work in pH ranges below 6.5 (up to pH 5) and dispense with the addition of complexing agents.