>> L Carnitine
1. Skin care new ingredients.
Business Libarary, Kobo Products, Inc. South Plainfield, NJ.
INCI name: L-carnitine and arbutine
Use levels: 2-10%
Applications: Skin lightener, skin turnover accelerant
Comments: This new approach utilizes skin lightening agents coupled with skin turnover accelerants. Natrulon LAC, a proprietary blend, allows
formulators to take cost-effective advantage of the different mechanisms for reducing skin pigmentation."
2. Hydrating power of L-Carnitine.
"Since L-Carnitine is hygroscopic, even small amounts are able to hydrate the skin, leaving it soft, smooth and moisturized. A human panel test
was carried out, in which sites on the forearms of the panelists were either untreated, treated daily with a placebo formulation, or treated daily
with a formulation containing 2% L-Carnitine. Corneometer readings were then taken at each site to determine hydration levels. The hydration
level of skin treated with L-Carnitine increased by 26.4%, compared to 12.5% for the skin treated with placebo. As expected, the hydration level
of the untreated skin did not change significantly."
3. Influence of L-Carnitine on epidermal turnover rate.
Ulla Held, Lonza AG, Muenchensteinerstr. 38, 4002 Basel,Switzerland.
"The ability of exfoliating Alpha hydroxy acids such as glycolic and lactic acids to accelerate the turnover rate of skin cells is well known.
Similarly, L-Carnitine, a Beta hydroxyl acid, exhibits excellent skin exfoliating properties, even at low levels. This exfoliating effect manifests itself
as acceleration in epidermal turnover rate. In healthy skin, the outermost cells in the horny layer are constantly being sloughed off and replaced
by new cells generated in the basal layer of the epidermis. The time needed by a new generation of cells to travel from the basal to the upper
horny layer is the epidermal renewal time. When the equilibrium of the skin is altered, dead cells tend to accumulate in the outer layers, the
turnover rate declines and the renewal time increases. As we age, the time required for skin renewal also increases. In young and middle aged
adults the renewal time is approximately 20 days, whereas in adults over 50 the rate of turnover slows and the renewal time increases to
approximately 30 days. Removing the dead skin cells and increasing the rate of skin turnover typically results in younger and healthier-looking
skin. The rate of skin turnover is generally determined by the time that it takes for skin treated with a fluorescing dye to loose its fluorescence.
In-vivo determination of turnover time, in which the dye was applied to the forearms of human volunteers followed by topical treatment with
either a placebo (cream vehicle) or a cream containing 2% L-Carnitine for a period of 28 days, clearly shows that application of L-Carnitine does
indeed accelerate skin turnover. In the trial, skin was renewed after an average of 18 days with L-Carnitine treatment and after 21 days with
placebo treatment, whereas untreated skin required 23 days. This is equivalent to a 12% increase in epidermal turnover rate."