HYDRO-B18

THE WATER-SOLUBLE FORM

OF 18-ß-GLYCYRRHETINIC

ACID

HYDRO-B18

INTRODUCTION

Glycyrrhiza glabra develops a large rhizome from which the stolons and roots branch out; during the autumn these are harvested from 3-4 year-old plants and then dried.According to a monograph published by ESCOP (European Scientific Cooperative on Phytotherapy), licorice root contains not less than 4% glycyrrhizic acid, calculated on the weight of the dried spice. Licorice root is prescribed in numerous traditional Japanese Kampo medicine remedies and Western tradition, too, makes mention of Glycyrrhiza.

HYDRO-B18

INCI NAME CHEMICAL COMPOSITION

The main components of licorice root are:

• triterpenic glucosides, 2-15% of which are saponins, mainly glycyrrhizic acid, the 3 ß-diglucuronide of glycyrrhetinic acid, found as a mixture of calcium and potassium salts known as glycyrrhizin;

• flavonoids (1-2%) such as liquiritin;• flavanones such as glabrol;• isoflavonoids such as glabrene;• isoflavans such as glabridin;• chalcones such as isoliquiritin;• coumarins such as liqcoumarin;• polysaccharides;• essential oils (0.05%)

Glycyrrhizic acid appears as a characteristically sweet, white powder.It is soluble in water and in hydroalcoholic solutions; at low pH it is soluble in glycerine and propylene glycol.

Aqua, Polyglyceryl-6 Caprylate, Glycyrrhetinic Acid, Proline

HYDRO-B18

EXTRACT OR PURE PRODUCT?

In the field of natural products, there are several approaches to using phytocosmetic ingredients. The use of pure, chemically defined products — as compared to extracts drawn from fresh plants or dried herbs — is part of amore recent approach involving the continuous evolution of extraction systems and subsequent concentration and purification operations to obtain the pure product.

Using a chemically pure product in a phytocosmetic means standardizing the doses and effects, ensuring reproducibility and allowing rigorous analysis of the components in the finished cosmetic. Interpretation of the biological effects may also be more clear-cut since they can be traced back to the dose of a pure functional ingredient.

For the formulator, in comparison with an extract, using a chemically defined product:

1. has less effect on the finished product’s organoleptic properties, its odor, color or any opalescence;

2. requires the use of smaller quantities;3. has a less destabilizing effect on the final product. For

example, the solvents used to extract a fluid can throw the formulation out of balance;

4. limits use of preservatives;5. verifies the quality of the raw material received;6. facilitates determination of the amount of active

substance present in the finished cosmetic.

HYDRO-B18

ANTI-ITCHING ACTION ANTIBACTERIAL PROPERTIES

The biological mechanism that gives rise to the itching of chronic dermatitis has yet to be defined and thus how glycyrrhetinic acid reduces this symptom remains to be clarified. Some studies have been conducted on the involvement in chronic pruritus of mediators other thanhistamine, i.e. substance P and tryptase. In particular, the role of glycyrrhetinic acid in reducing the chronic pruritus associated with substance P — achieved by reducing the level of leukotrienes B (4) produced — has been described (Akasaka Y et al., 2011).

The antibacterial efficacy of glycyrrhetinic acid and other derivatives of licorice has been described (Marjan Nassiri Asl et al, 2008) on H. pylori, E. coli, S. aureus, K. pneumonia, E. erogene, B. subtilis. Ancient manuscripts from China, India and Greece indicate that these plants were used to treat viral respiratory tract infections and hepatitis.

HYDRO-B18

MELANOGENIC ANDANTIOXIDANT ACTION

SENSITIVE SKIN

In vitro studies on cell lines have shown that a treatment with glycyrrhizin and its aglycone, glycyrrhetinic acid — both before and during sun exposure — prevents oxidative damage (Rossi T, et al., 2005).

Sensitive skin is more susceptible to such skin conditions and disorders as atopic dermatitis, erythema, couperose and rosacea. The most common drugs for the local treatment of inflammation are corticosteroids which produce powerful, rapid anti-inflammatory and antiproliferative effects. These molecules penetrate the cell membrane where they are activated and recognized by endonuclear receptor sites, interacting with the RNAm and affecting new protein synthesis and cell activity.

In particular, topical cortisones:

1. produce vasoconstriction;2. inhibit cell proliferation;3. produce anti-inflammatory and immunosuppressive

effects.

However, use of a topical corticosteroid can have side effects. Often the disorder is chronic with alternating phases of flare-up and remission, caused by frequent use of topical steroid therapy which leads to such major side effects as skin irritation and sensitization, promotion of infection (masking or worsening of some bacterial infections), steroid acne, striae distensae, skin atrophy, telangiectasis, hypertrichosis and perioral dermatitis.

HYDRO-B18

HYDRO-B18 AS CORTISONE-LIKE INGREDIENT

When topical pharmacological treatments are applied frequently - such as in subjects with atopic dermatitis - sensitization to some of the excipients in the medicinal product may be suspected. In this case, a cosmetic emulsion formulated with a cortisone-like ingredient such as glycyrrhetinic acid, can offer multiple advantages:

1. it relieves skin irritations without the typical side effects of corticosteroids;

2. it can exploit the synergy of multiple multifunctional ingredients. Antioxidants such as the Coenzyme Q10, tocopherol and carbocysteine can be introduced to restore the skin barrier; likewise ceramides, unsaturated

fatty acids or anti-reddening agents such as bisabolol, etc. can also be added;

3. it can be applied daily as part of a preventive hygiene and skin care regime for sensitive skin;

4. it is indicated in paedocosmetics, in skin care products for infants who have not yet developed a protective hydro-lipid film or acid mantle.

5.

HYDRO-B18

HYDRO-B18 IN COSMETICS

HYDRO-B18, the water-soluble form of 18-ß-glycyrrhetinic acid, is a transparent, straw-yellow, odorless liquid. It has a neutral pH and is soluble in water, glycerol and propanediol. In skin care and personal hygiene, it acts as penetration enhancer, preventing redness and having an itch-calming, moisturizing effect. It has tensioactive and self-emulsifying properties that can be harnessed to stabilize emulsions; it also has antibacterial and anti-inflammatory effects.HYDRO-B18 meets BDIH and COSMOS criteria.

In the formulation of products specific for skins sensitive to external agents, aggressive cleansing, topical therapies and exposure to sunlight, HYDRO-B18 is particularly indicated for preparations to reduce edema and for serums to reduce bags around the eyes.

The presence of HYDRO-B18 leads to the formation of

mixed micelles with the primary surfactant, micelles that are larger and stiffer and thus have difficulty interacting with the skin barrier. Even leave-on products can benefit from the soothing potential of HYDRO-B18 when applied to highly delicate, sensitized skin.

In recent decades, new systems have been developed for cutaneous transport of functional substances. The aim is to obtain a steady rate of functional substance release from the topical preparation and ensure that it reaches the site of action. Likewise, systems such as liposomes, phytosomes, nanoemulsions, polymeric nanoparticles, etc. — that improve active substance bioavailability, protect it from chemical-physical breakdown, improve absorption and boost effectiveness — have been introduced in phytocosmetics. HYDRO-B18 proves to be perfectly integrated in these systems.

HYDRO-B18

CONCLUSIONS

For the intended concentrations and uses, 18-β-glycyrrhetinic acid, glycyrrhizin and their derivatives have been declared “safe” by the Expert Panel of CIR (Cosmetic Ingredient Review). These are excellent ingredients with a wide range of possible functions and applications in the field of cosmetics. The tradition has been reported over the millennia, and modern pharmacology has confirmed its effectiveness, its mechanism of action and its potential.

Given its high degree of purity, Hydro-B18 is absolutely safe for use in formulations. Thus finished product quality control can be easily performed with appropriate analytical techniques, a truly important feature given the increasing focus on the safety, quality and functionality of cosmetic products.Numerous studies have been conducted on cosmetic products containing 18-β-glycyrrhetinic acid, an ingredient

considered dermatologically safe and effective. However, creating formulas with this active principle is a real “challenge”, since the limited — and highly selective — solubility of 18-β-glycyrrhetinic acid requires particular technological devices and precise formulation choices.

Hydro-B18 provides a solution to these problems, a satisfactory response to research into drug delivery, conducted to improve the solubility, stability and cutaneous release of this important active ingredient.

In the current landscape, which sees a marked increase in pathologies associated with sensitive skin — both atopic and allergic as well as contact dermatitis— the use of cosmetics with soothing properties is increasingly important. In this context Hydro-B18, designed and developed in the SOCRI Technical Centre, appears to be a natural, effective and innovative asset.

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