Products
Hyaluronic acid is commercially available in the form of creams, nasal creams, nasal sprays, cosmetics, lozenges, eye drops or gels, and injectables, among others. The injectables are also combined with local anesthetics such as lidocaine to prevent pain. Hyaluronic acid was first isolated from bovine eyes in the 1930s.
Structure and properties
Hyaluronic acid is a linear glycosaminoglycan and heteropolysaccharide composed of disaccharide units of D-glucuronic acid and -acetyl-D-glucosamine. The repetition of the two building blocks results in polymers of different sizes. Hyaluronic acid can also be present in low molecular weight (LMWHA, low molecular weight HA). It is extracted from rooster combs or obtained biotechnologically by fermentation with bacteria (-species). The sodium salt sodium hyaluronate is present as a white and very hygroscopic powder or fibrous aggregate that is sparingly soluble in water. Hyaluronic acid is a natural substance found in the human body in the skin, connective tissue (extracellular matrix), cartilage, synovial fluid, bones and the eye (vitreous body), among other places. There it binds water, provides volume and structure, and ensures elasticity. In cosmetic products, hyaluronic acid is also partly present in stabilized and modified form. This is because the unstabilized molecule has a relatively short half-life in the body.
Effects
Hyaluronic acid has water-binding (hydrating), gel-forming, viscoelastic, volumizing, firming, anti-inflammatory and pro-inflammatory, regenerative and wound-healing properties. The “antidote” is the enzyme hyaluronidase, which dissolves hyaluronic acid.
Fields of application
Preparations containing hyaluronic acid are used very widely. The areas of application include (selection):
- For wound healing in ulcers, ulcers, decubitus, burns.
- Dry nasal mucosa
- Dry eyes see under hyaluronic acid eye drops
- Dry skin, skin diseases
- Intra-articular for osteoarthritis See intra-articular hyaluronic acid.
- Vaginal dryness
- For cosmetic applications, for example, for the so-called “injection” of the lips (lip augmentation), correcting lines and wrinkles, for volume filling, for scars and stretch marks.
Dosage
According to the instructions for use.
Contraindications
Contraindications depend on the product. They include (selection):
- Hypersensitivity
- Blood clotting disorders (injection)
Full precautions can be found in the drug label.
Adverse effects
Possible adverse effects of the products include local reactions and hypersensitivity reactions. As a natural and biocompatible substance, hyaluronic acid is generally well tolerated when used locally. Various side effects may occur with the injections, such as pain, induration, bruising, itching, swelling, redness and allergic reactions. Rarely, complications are also possible.
