Collagen in Cosmetics

Collagen is the main fibrous protein of connective tissue in animals and is the most abundant protein in mammals, accounting for 25-35% of total body protein content. Collagen accounts for 1-2% of muscle tissue and 6% of strong tendinous muscles. Collagen, rich in proline and hydroxyproline, has great tensile strength, and is the main component of fascia, cartilage, ligaments, tendons, bone and skin. Along with soft keratin, it is responsible for skin strength and elasticity. Its degradation leads to wrinkles that accompany aging.

The molecular structure is not known exactly, but it is analogous to a three-strand rope where each strand is a polypeptide chain. The molecular weight is about 100,000.

Collagen is converted to gelatin by boiling water which hydrolyzes it to a mixture of degradation products.The nutritional value of gelatin is questionable, as it does not contain all the essential amino acids in the proper proportions that the body needs. The name collagen is derived from kola, the Greek word for glue.Collagen or “glue producer” refers to the early process of boiling the skin and sinews of horses and other animals to obtain glue—a process used by Egyptians about 4000 years ago.

Collagen has an array of dental, orthopedic and surgical applications, including cosmetic surgery. It is used as a healing aid for burn patients, in bone reconstruction and as an artificial skin substitute. Most medical collagen is derived from cattle or pigs, but more expensive human collagen is available from cadavers, placentas and aborted fetuses.

Cosmetic uses include skin and hair products. EMD Chemicals, Gibbstown, NJ, markets a synthetic collagen product for use in skin care called RonaCare ASC 111 (INCI: Water, lecithin, dipalmotyl hydroxyproline, phenoxethanol, tall oil sterol, linoleic acid, tocopherol, sodium ascorbate, mannitol, methylparaben, ethylparaben, propylparaben, butylparaben).

There are at least 10 structurally distinct collagen types. Collagen III is predominant in young skin; it appears during the wound healing process and is referred to as a “restructuring” collagen. With aging, a significant decrease in collagen synthesis occurs, leading to the appearance of lines and wrinkles.

When the skin is damaged by external stress such as UV irradiation, the fibroblasts start to resynthesize the damaged structures. These biological signals to the fibroblasts are called “cytokines.” Rona- Care ASC III is said to be an effective amplifier of collagen III production because it sends cytokines to enhance fibroblast activity. The increase in pro-collagen III increases the epidermal layer thickness and reforms collagen fibers in the dermis.It is claimed that RonaCare repairs the natural support layer which lies just under the skin to increase skin elasticity and smoothness to reduce facial lines and wrinkles.

The use level in formulas is 2-6%, the preferred pH is 5.5-6.5 and the temperature of addition is 35°C. The material is incompatible with ionic emulsifiers, surfactants, short chain ethoxylates, bivalent cations, fruit acids and high alcohol concentrations >15%.

A suggested formula is:

Age-Defying Lotion

Ingredient:%Wt.
Phase A
Waterq.s. to 100
Propylene glycol2.00
Glycerine3.00
Allantoin0.2
Carbomer0.2
Phase B
Caprylic capric triglyceride3.00
Isopropyl myristate3.00
Cetyl alcohol, glyceryl stearate,3.50
PEG-75, stearate, ceteth 20,
steareth 20
PEG-8 (and) tocopherol (and) 0.10
ascorbyl palmitate (and)
ascorbic acid(and)citric acid
Triethanolamine (TEA)0.35
Phase C
RonaCare ASC III4.00
Propylene glycol, DMDM 0.80
hydantoin, propylparaben,
methylparaben

Procedure: Heat A ingredients 1-4 to 50°C to dissolve solids. Sift in carbomer and heat to 65°C. Heat B ingredients 1-4 in separate container to 65-70°C and add to A. Homo- genize. Add TEA at 55-60°C. Continue homogenizing and cool batch to 35-40°C. Adjust pH with TEA to 6.8-7.2. Add C at 30-33°C and stir gently until homogeneous.

About the Author
Harvey Fishman has a consulting firm at 34 Chicasaw Drive, Oakland, NJ 07436, hrfishman@msn.com, specializing in cosmetic formulations and new product ideas, offering tested finished products. He has more than 30 years of experience and has been director of research at Bonat, Nestlé LeMur and Turner Hall. He welcomes descriptive literature from suppliers and bench chemists and others in the field.