Centuries ago oranges were found to help prevent and cure scurvy.  In the 1920's, Albert Szent-Gyorgi, a Hungarian scientist, discovered ascorbic acid, vitamin C, in the adrenal gland.  He won the Noble Prize for his studies in 1936 and continued his research, utilizing vitamin C to fight diseases such as cancer.
Today, research on the powerful benefits garnered from vitamin C continues.  In addition to its disease-fighting attributes, vitamin C has also been found to be an effective ingredient in skin care treatments.  In 1992, Dr. Sheldon Pinnell conducted studies proving a variety of benefits of ascorbic acid.  Since then, additional studies helped to discover further benefits.  Vitamin C has been proven to:
• Promote collagen synthesis
• Be a major anti-oxidant
• Act as an anti-inflammatory
• Inhibit the enzyme tyrosinase (in certain vitamin C derivatives)
 
Collagen is responsible for providing suppleness and elasticity in the skin.  As we age, the level of collagen in the skin is reduced.  Collagen and elastin fibers stiffen and break apart, forming an unstructured mass.  In turn, wrinkles are formed.
For years, moisturizers have contained collagen for elastin.  But, the collagen and elastin must be produced as part of the living cell.  Delivering vitamin C to the stratum basale level where new live cells are produced is the only way to improve the availability of collagen.  Studies have proven that topically applied vitamin C can improve the production of collagen.  Massaging creams with collagen and elastin are not able to accomplish this.
Vitamin C offers no benefits in the absorption of ultra violet light, and as such is not a sunscreen.  Yet, topically applied vitamin C acts as a major anti-oxidant.  Anti-oxidants fight against oxygen free radicals, which are stimulated by exposure to UV light, tobacco smoke, and other environmental insults.  These oxygen free radicals can damage and destroy the skin.  Topical vitamin C counteracts by neutralizing them.
When used in the formulations after exposure to UV light, the vitamin C works to control the inflammatory reaction associated with sunburn.  Currently, due to their anti-inflammatory properties, some dermatologists are experimenting with vitamin C formulations for post-laser surgery, as well as speeding the healing process.
Not all vitamin C derivatives are creates equal. After studying a variety of derivatives, it was found that certain types of vitamin C derivatives inhibited the enzyme tyrosinase, allowing them to act as whitening agents.  Tyrosinase is a rate regulating enzyme, responsible for the production of melanin.  Typical tyrosinase inhibitors are hydroquinone and kojic acid.  Ascorbic acid, ascorbyl glucoseamine and ascorbi-cell report the ability to inhibit tyrosinase, in turn, making these types of vitamin C a better alternative to hydroquinone and kojic acid.  Magnesium ascorbyl phosphate and ascorbyl palmitate were reported to have no effect on tyrosinase, and in turn were predicted to not have any effect on melanin synthesis.
 

WHY DID IT TAKE SO LONG?
With vitamin C becoming the foremost active, since the introduction of Alpha Hydroxy Acids, cosmetic companies are racing to incorporate one form or another of vitamin C in skin care formulations.  One may ask that if vitamin C is so good for you, why is it only recently that is has been introduced in skin care products.  The answer is simple.  With all of its benefits, vitamin C has two major hurdles...how to develop a stabilized form of vitamin C and how to deliver it in an effective level.
The key to topically applied vitamin C is the availability of effective L-ascorbic acid.  Ascorbic acid is extremely unstable in the presence of light and oxygen.  It is normal for a vitamin C formulation to have a light, natural tan color.  But, as the ascorbic acid deteriorates, it continues to turn dark brown and becomes less effective or even ineffective.
Some quick to join the ranks with vitamin C products have added only small amounts of ascorbic acid or a derivative to the product, allowing for a reference to :vitamin C" on the packaging.  Others are turning to other forms or derivatives, such as magnesium ascorbyl phosphate, ascorbyl palmitate, ascorbyl stearate, ascrobosilane, Ascorbyl Glucoseamine, Sun Caps-C, ascorbic acid sulphate Stableact C Plus, Ascorbi-Cell.  When each of these forms is utilized, the active must be converted to
L-ascorbic acid in high enough concentrations to be effective.
Dr. Pinnell's studies claim that with a low pH of 2.5 - 3.5, the ascorbic acid can be absorbed into the skin.  This is extremely irritating to the skin, just like Alpha Hydroxy Acids, which is key, according to Dr. Pinnell's study.
Low pH's and irritating the skin may be fine for those under the supervision of a dermatologist or esthetician, but not for products being marketed directly to the consumer.  Formulators must develop a method of delivering effective levels of vitamin C without irritating the skin.  Various derivatives of vitamin C have claimed to deliver the active without irritating the skin, such as Ascorbyl Glucoseamine, Ascorbi-Cell, Triple Action Vitamin C, and ascorbyl palmitate (a fatty ester), which utilizes a slightly higher or more neutral pH than ascorbic acid.
 

WHAT’S THE DIFFERENCE?
Ascorbyl Glucoseamine utilizes 19 percent ascorbic acid with a polyglucoseamine complex to protect the ascorbic acid and retard the oxidation process.  In one study, Ascorbyl Glucoseamine demonstrated to prevent 65 percent of UV induced lipid peroxidation, outperforming melanin liposomes and encapsulated ascorbyl palmitate.
One plus two equals four.  Ascorbi-Cell combines a botanical complex with two types of vitamin C for a synergistic effect.  The end result is the ability to deliver an effective amount of vitamin C, without irritation.
Triple Action Vitamin C is a patent pending complex, combining free flowing L-ascorbic acid, sodium ascorbate and ascorbyl glucoseamine with alpha hydroxy acid, specifically glycolic acid.  This complex provides an exfoliating effect from the glycolic acid at the upper layer of the skin, while the vitamin C provides multiple benefits at the lower level of the skin.
Some of the fatty esters, such as ascorbyl palmitate, is a synthetic ester of vitamin C in an oil soluble form versus ascorbic acid, which is a water soluble form.  Recently, this material has been more openly promoted.  But in June of 1998, ICMAD (Independent Cosmetic Manufacturers and Distributors) alerted its members to a potential patent pending being asserted for certain topical applications of fatty esters of ascorbic acid, including Ascorbyl Palmitate.
Sun Caps C offers an encapsulated form of ascorbic acid.  The low viscosity dispersion delivers 20 percent ascorbic acid in a cyclomethicone base.  This unique delivery system allows for easy incorporation into the oil or silicone phase of a skin care formulation.
Using advanced multiple phase emulsion technology, Stableact C Plus provides a unique combination of 10 percent ascorbic acid and 1 percent green tea extract in a stable form.  Stableact systems are poly-silicone emulsions.  Hydrophilic actives, ascorbic acid and green tea in this case, are contained in a propylene glycol phase which is then dispersed in a silicone base.
Keep in mind that these are the raw materials, and the amount of ascorbic acid supplied in the finished product is reduced by the percentage of the raw material utilized in the final formulation.
 

DELIVERING SIGNIFICANT RESULTS
Vitamin C has definitely proven to be a mainstay in the cosmetic industry.  A formulator must first decide which technology to subscribe to: irritating or non-irritating.  Next, the formulator must decide which active complex will provide the greatest amount of ascorbic acid in a stabilized format. Using effective levels will only help to build the vitamin C category, by providing consumers with truly active, therapeutic skin care treatments. Vitamin C has definitely proven to be a mainstay in the cosmetic industry.  A formulator must first decide which technology to subscribe to: irritating or non-irritating.  Next, the formulator must decide which active complex will provide the greatest amount of ascorbic acid in a stabilized format. Using effective levels will only help to build the vitamin C category, by providing consumers with truly active, therapeutic skin care treatments.