L-Ascorbic Acid and other Vitamin C Derivatives
Vitamin C, in the form of L-ascorbic acid, is
one of the relatively few topical agents whose effectiveness against
wrinkles and fine lines is backed by a fair amount of reliable
scientific evidence. For many however, high potency vitamin C irritates the skin. If this is the case, switching to a vitamin C derivative provides the highly studied benefits of topical vitamin C without the redness, stinging or irritation that can occur with high concentrations of l-ascorbic acid or using a time released cream formulation of Vitamin C is another alternative.
To improve the practicability of
vitamin C in skin care, scientists have been looking for its relatives
with comparable or superior skin benefits. An ideal vitamin C
derivative should be able to easily penetrate into skin cells and
release L-ascorbic acid in amounts sufficient to boost collagen
synthesis. Also, it should be more stable and less irritating than
vitamin C. So far, two compounds have found their way into the broad
skin care market: ascorbyl palmitate and magnesium ascorbyl phosphate.
A few other highly promising derivatives are on the horizon.
Ascorbyl palmitate
Ascorbyl palmitate is the most
widely used fat-soluble derivative of vitamin C in skin care. It is
nonirritating and more stable than vitamin C. Furthermore, ascorbyl
palmitate is a fat-soluble antioxidant and is at least as effective as
vitamin E in protecting the skin from lipid peroxidation (a key type of
free radical damage in the skin). Unfortunately, it appears that the
concentrations of ascorbyl palmitate achievable in skin care formulas
do not boost collagen synthesis as much as vitamin C.
Numerous skin care products
containing ascorbyl palmitate are commercially available. When buying
products with ascorbyl palmitate (or other vitamin C-derived skin care
for that matter), it is best to choose colorless or white formulation.
That way you can spot the advanced stages of oxidation of the active
ingredient by the emergence of a yellowish tint. Unfortunately, the
lack of tint does not guarantee complete lack of oxidation because the
early oxidation products are colorless.
Magnesuim ascorbyl phosphate
Magnesuim ascorbyl phosphate is a
water-soluble derivative of vitamin C rapidly gaining popularity in
skin care. It is nonirritating and more stable than vitamin C. Most
importantly, magnesuim ascorbyl phosphate appears to have the same
potential as vitamin C to boost skin collagen synthesis but is
effective in significantly lower concentrations. Overall, magnesuim
ascorbyl phosphate appears to be a better choice than vitamin C for
people with sensitive skin and those wishing to avoid any concomitant
exfoliating effects. (Most vitamin C formulas are highly acidic and
therefore produce exfoliation.)
Skin care products with magnesuim
ascorbyl phosphate are available and their number is growing. Be
careful though. Many products contain less than effective concentration
and fail to boost collagen synthesis. Also, even though magnesuim
ascorbyl phosphate is several times more stable than vitamin C, it
still gradually degrades when exposed to light and air. Hence freshness
and proper storage are important.
Next generation of vitamin C derivatives
Most vitamin C derivatives on the
market, including ascorbyl palmitate and magnesuim ascorbyl phosphate,
consist of the ascorbic acid fragment (ascorbyl) and a fragment of
another acid (e.g. palmitate or phosphate). Recent research indicates
that new vitamin C derivatives consisting of multiple chemical
fragments bound to a single ascorbic acid fragment may work even
better. These new derivatives are more stable compared to both vitamin
C and older derivatives. Furthermore, some of these newcomers
(particularly the so-called tetrasubstituted lipophilic ascorbates)
also appear to be more powerful boosters of collagen synthesis. Even
though relatively few skin care products currently on the market
contain these new compounds, they may become widely used as more
evidence of their benefits accumulates.
Bottom line
While unmodified vitamin C
remains an important skin care ingredient, its derivatives may do a
better job in some situations. They tend to be more stable, more
affordable and less irritating. Furthermore, some of the derivatives
may even be as effective in boosting skin collagen synthesis. On the
other hand, unmodified vitamin C may be a better choice if you want to
stimulate collagen synthesis and exfoliate at the same time. High
potency vitamin C products are highly acidic and therefore have
exfoliating effect.
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