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Sodium Acetylated Hyaluronate (AcHA; INCI: Sodium Acetylated Hyaluronate) is a chemically modified hyaluronic acid derivative designed to combine the moisturizing properties of hyaluronate with improved skin affinity, stability and dermal bioavailability.
This review covers nomenclature and identifiers, chemistry and structure, synthesis and manufacture, physico-chemical properties, mechanisms of action (hydration, extracellular matrix protection, barrier interactions and penetration), analytical methods, formulation and application in cosmetics and dermato-pharmacy, safety and regulatory considerations, environmental fate, comparative performance versus other HA derivatives, representative clinical / ex vivo evidence and practical formulation recipes and quality specifications.
Key claims and mechanistic points are supported by peer-reviewed studies and industry technical sources
Common synonyms: Acetylated hyaluronic acid; AcHA; Sodium acetyl hyaluronate; Acetyl-HA; Sodium acetylated hyaluronan.
CAS registry numbers (reported in suppliers/literature): several entries exist in commercial databases — e.g. 287390-12-9 and 158254-23-0 have been reported; note that older/confused listings sometimes show the CAS for parent sodium hyaluronate (9067-32-7). Users should confirm the CAS number on the specific supplier's COA and material specification because commercial listings vary.
Sodium Acetylated Hyaluronate is a derivative of hyaluronic acid (HA, a linear glycosaminoglycan composed of repeating disaccharide units of D-glucuronic acid and N-acetyl-D-glucosamine).
In sodium acetylated hyaluronate, additional acetyl groups are introduced at selected hydroxyl or amino functionalities (or via O-acetylation/N-acetylation approaches, depending on process) producing a partially acetylated sodium hyaluronate.
The acetylation increases amphiphilicity (introduces slightly more lipophilic character) while generally preserving the hydrophilic backbone and polyanionic nature of HA.
Representative empirical formulae for a single disaccharide unit can be written (depending on acetylation degree), and the polymer remains an anionic sodium salt in cosmetic grade materials.
Consequences of acetylation on molecular behaviour
Increased resistance to enzymatic degradation (partial protection against hyaluronidases) depending on degree/site of acetylation.
Modified water-binding dynamics and stronger adhesion to skin surface and extracellular matrix elements.
Improved skin affinity and potential for deeper penetration when molecular weight is reduced or when combined with appropriate formulation carriers.
Synthesis and manufacturing methods (industrial overview)
Commercial sodium acetylated hyaluronate is typically produced by selective acetylation of sodium hyaluronate (microbially produced HA from fermentation). General process steps seen in supplier descriptions:
Feedstock: Sodium hyaluronate (from microbial fermentation — Streptococcus species or engineered strains).
Activation/Acetylation: Controlled reaction with acylating agents (commonly acetic anhydride or acetyl chloride under mild basic/acidic catalysis) to introduce acetyl groups on hydroxyls or amine positions, with conditions selected to limit depolymerization.
Quench and neutralize: Reaction quench and neutralization to sodium salt form.
Purification: Filtration, diafiltration/ultrafiltration to remove low-MW impurities and reagents, then spray-drying or lyophilization to obtain powder (or kept in aqueous solution).
Standardization: Adjustment to target molecular weight fraction (some manufacturers produce low-MW acetylated HA ~ 1–50 kDa; others supply 20 kDa, 50 kDa etc.), determination of degree of acetylation (DoA) and removal of residual reagents and endotoxins.
Quality attributes controlled: molecular weight (Mw and polydispersity), degree of acetylation (mol% acetylation per disaccharide), sodium content, residual solvents/reagents, protein/endotoxin levels, microbial limits.
Physico-chemical properties
Appearance: white to off-white powder (spray-dried) or viscous aqueous solution.
Solubility: readily soluble in water; insoluble in nonpolar organic solvents. Forms viscous aqueous gels depending on MW and concentration.
pH: aqueous solutions typically near neutral (pH 5–8) depending on formulation and counterions.
Hygroscopicity: hygroscopic — binds water strongly due to remaining carboxylate and hydroxyl groups.
Molecular weight: available across a range (low-MW fractions for penetration, medium for film formation and hydration, high-MW for surface humectancy).
Many suppliers provide specific grades (e.g., ~20 kDa, 50 kDa).
Mechanisms of action — biological and physical effects on skin
Hydration and humectancy
Like native hyaluronic acid, sodium acetylated hyaluronate binds large volumes of water per unit mass and forms a hydrated matrix that increases skin hydration and plumps the stratum corneum.
The acetyl moieties alter water-binding dynamics and surface affinity which can improve retention of water at the skin surface and within superficial epidermal layers.
Skin affinity and semi-immersion film formation
The partial acetylation adds amphiphilic character and improves adsorption/affinity to epidermal lipids and proteins — enabling a “semi-immersed” arrangement where polymer chains anchor to the surface while keeping strongly hydrated domains.
This increases persistence of hydration and reduces transepidermal water loss (TEWL) in some studies. Supplier technical descriptions emphasize “high skin affinity” and persistent moisturizing performance.
Penetration and molecular size effects
Skin penetration of hyaluronate species depends strongly on molecular weight.
Low-MW and hydrolyzed fractions penetrate more readily; acetylated derivatives engineered at low molecular weight can reach deeper epidermal layers more effectively, potentially influencing dermal ECM or signaling.
Reviews of hyaluronan skin delivery discuss multiple penetration mechanisms and the role of molecular size, charge and formulation excipients.
ECM protection and anti-wrinkle activity — biological signalling
Preclinical and ex vivo data indicate that specifically grafted/acetylated HA derivatives can reduce ECM degradation (e.g., reduce matrix metalloproteinase induction, protect collagen/elastic fiber networks) and modulate gene expression in aged fibroblasts, leading to measurable reduction in wrinkle depth and skin roughness in controlled studies.
A targeted study on sodium acetylated hyaluronate reported anti-wrinkle effects and transcriptomic evidence of ECM protection.
Evidence: in vitro, ex vivo and clinical data
Transcriptomic / mechanistic study: Meunier et al. developed a grafted/acetylated HA and reported protective properties against ECM degradation and significant anti-wrinkle outcomes in cosmetic testing.
The paper presents mechanistic and efficacy data supporting claims that strategic acetylation and MW selection produce measurable anti-aging benefits.
Reviews on delivery and penetration: Comprehensive reviews summarize how hyaluronan derivatives and low-MW species penetrate to different skin layers and how structural modifications (e.g., acetylation) can influence delivery and stability.
These reviews provide theoretical and experimental bases for improved bioavailability of modified HA species.
Usage frequency and safety listing: Cosmetic ingredient safety committees list sodium acetylated hyaluronate among high-use hyaluronate derivatives and include it in priority lists for monitoring; safety assessments and reported use concentrations are tracked in industry safety reviews (CIR, etc.).
Typical concentrations and formulation uses
Common product categories: facial serums, essences, toners, moisturizers, eye creams, sun care (after-sun), cleansers, leave-on masks; also used in medicated topical vehicles when hydration or barrier repair is required.
Typical use concentrations:
Leave-on facial products: 0.05–1.0% (depending on grade and desired viscosity/hydration).
Serums/ampoules with low-MW AcHA for penetration: 0.1–0.5%.
Rinse products (cleansers): lower concentrations (0.01–0.2%) primarily for skin feel and mild hydration.
Formulation notes: AcHA dissolves readily in water; heating is unnecessary and may cause depolymerization if excessive.
It is compatible with common cosmetic pH ranges (4–8) but stability should be validated at the intended pH, in presence of chelators, preservatives, and actives (vitamins, peptides).
Combination with other humectants (glycerin, sorbitol), occlusives (dimethicone) or barrier lipids can produce synergistic hydration and barrier repair effects.
Analytical methods and quality control
Essential characterization methods:
Molecular weight distribution: SEC-MALS (size exclusion chromatography with multi-angle light scattering).
Degree of acetylation (DoA): 1H-NMR or 13C-NMR quantification, and/or colorimetric assays after hydrolysis.
Purity / identity: FTIR, UV/Vis (where applicable), specific hyaluronan assays (carbazole or carbazole-like assays for uronic acid content).
Residual reagents: GC for solvent residues, HPLC for low-MW impurities.
Microbial & endotoxin testing: total aerobic count, yeast/mold, specified pathogens; endotoxin (LAL) if used in sterile or ophthalmic/medical products.
Rheology and viscosity: Brookfield or oscillatory rheometry for solution viscosity characterization.
Stability and storage
Storage: cool, dry place; avoid prolonged exposure to heat and light.
For aqueous solutions, include broad-spectrum preservatives or aseptic manufacturing to prevent microbial growth.
pH sensitivity: stable across common cosmetic pH ranges but acid/base extremes and high temperatures accelerate depolymerization and reduce viscosity.
Validate shelf life under intended conditions.
Packaging: airtight, opaque containers recommended for bulk powders and concentrated solutions to limit moisture uptake and microbial contamination.
Safety and regulatory considerations
General safety consensus: Hyaluronate derivatives (including sodium acetylated hyaluronate) are widely used and generally considered safe when properly manufactured and formulated.
Industry safety reviews list acetylated derivatives among commonly used hyaluronate materials being monitored.
Cosmetic safety assessments (e.g., CIR and similar) include hyaluronates and derivatives for review of use patterns and concentrations.
Potential concerns: impurities (residual reagents, endotoxins), microbial contamination in aqueous preparations, and incorrect molecular characterization (which can affect efficacy and irritation profile).
Standard patch testing and formulation safety testing (ocular safety if used periocularly) are recommended.
Regulatory status: Typically used as a cosmetic ingredient (INCI).
For medical/dermal injection uses, chemically modified hyaluronic acids follow stricter regulatory pathways and would require specific clinical/sterility/sterilization validation and regulatory approvals—commercial sodium acetylated hyaluronate sold for topical cosmetics is distinct from injectable crosslinked HA fillers.
Confirm intended use and regulatory jurisdiction before medical claims
SAFETY INFORMATION ABOUT SODIUM ACETYLATED HYALURONAT
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product
