Retinyl acetate
[CAS# 127-47-9]

Identification

• Classification: API >> Vitamins and minerals >> Vitamin AD drugs
• Name: Retinyl acetate
• Synonyms: all-trans Vitamin A acetate
• Molecular Formula: C₂₂H₃₂O₂
• Molecular Weight: 328.49
• CAS Registry Number: 127-47-9
• EC Number: 204-844-2
• SMILES: CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/COC(=O)C)/C)/C

Properties

• Density: 1.0±0.1 g/cm³ Calc.^*
• Melting point: |58 ºC (Expl.), |58 ºC (Expl.)
• Boiling point: 440.5±14.0 ºC 760 mmHg (Calc.)^*
• Flash point: 124.8±18.5 ºC (Calc.)^*
• Solubility: water soluble (Expl.), water soluble (Expl.)
• Index of refraction: 1.532 (Calc.)^*, 1.547-1.555 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS08 Danger
• Hazard Statements: H315-H360-H361-H413
• Precautionary Statements: P203-P264-P273-P280-P302+P352-P318-P321-P332+P317-P362+P364-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Reproductive toxicity	Repr.	1B	H360
Reproductive toxicity	Repr.	2	H361
Reproductive toxicity	Repr.	1A	H360
Reproductive toxicity	Repr.	1B	H360D
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Germ cell mutagenicity	Muta.	2	H341
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Carcinogenicity	Carc.	1B	H350
Flammable liquids	Flam. Liq.	3	H226

Discovory and Applicatios

Retinyl acetate is the acetate ester of all-trans-retinol and is used commercially as a stable, preformed source of vitamin A. Its chemical formula is C₂₂H₃₂O₂ (molar mass ≈ 328.49 g·mol⁻¹), and it is commonly listed under names such as vitamin A acetate or retinol acetate. Chemically, retinyl acetate is produced by esterification of the primary alcohol function of retinol with acetic acid (or by transesterification using an acyl donor), a straightforward transformation that yields an ester more resistant to oxidation and isomerization than the free alcohol. This enhanced stability is the principal reason retinyl acetate is preferred in many manufactured products over unesterified retinol.

Biochemically, retinyl acetate functions as a provitamin A: following oral ingestion it is hydrolyzed enzymatically to retinol in the intestine and is then absorbed, transported to the liver and other tissues, and may be re-esterified for storage as retinyl esters. The liver stores vitamin A predominantly in esterified forms; these stores supply retinol to peripheral tissues when required and serve as the principal systemic reserve. Enzymes and transport proteins that govern uptake, esterification, mobilization and conversion to active metabolites (for example, retinal and retinoic acid) have been characterised in mammalian systems, and established pathways explain how retinyl esters contribute to vision, cellular differentiation, immune function, and other vitamin A–dependent processes.

Industrial and practical applications of retinyl acetate fall into three main categories: food and nutritional fortification, dietary supplements, and topical personal-care/pharmaceutical formulations. As a food fortificant and supplement, retinyl acetate provides a stable, quantifiable form of preformed vitamin A suitable for incorporation into fortified foods, infant formulas and multivitamin tablets. Its physicochemical stability facilitates storage and processing compared with retinol, while intestinal hydrolysis ensures bioavailability. In topical formulations, retinyl acetate is used in creams, lotions and other skincare products both as a source of vitamin A activity and as a milder, more stable alternative to retinol; retinyl esters are converted in the skin to retinol and downstream active metabolites, contributing to collagen modulation and epidermal differentiation pathways that underlie many cosmetic claims.

Regulatory and safety assessments have shaped how retinyl acetate is used. Because preformed vitamin A can cause dose-dependent adverse effects, regulators and expert panels have evaluated acceptable use levels in foods, supplements and cosmetics. Regulatory opinions and reviews discuss systemic exposure from cosmetic use, safe concentration ranges in leave-on and rinse-off products, and the potential for aggregate exposure when dietary and cosmetic sources are combined. Clinical and toxicological literature documents the established risks of excessive intake of preformed vitamin A, including acute toxicity, chronic hypervitaminosis A and teratogenicity at high doses, and these findings underpin recommendations for upper intake limits and product labelling.

Manufacturing and formulation practice address the sensitivity of retinoids to light, heat and oxygen. Although the acetate ester is more stable than retinol, product development typically incorporates antioxidants, opaque or airless packaging, and controlled manufacturing conditions to minimize degradation and to preserve potency. Analytical and quality-control methods for retinyl acetate content and isomeric purity are routine in industry to ensure label accuracy and product safety.

In summary, retinyl acetate is a chemically simple but practically important retinyl ester whose value derives from balanced stability and bioavailability. It supplies preformed vitamin A in foods, supplements and topical products while permitting controlled exposure; its biochemical conversion to retinol and further metabolites integrates it into well-characterised vitamin A metabolic and physiological pathways. Safety considerations and regulatory guidance inform its permitted uses and concentrations so that functional benefits are achieved without exceeding established exposure limits.

References

2013. Retinol and retinyl esters: biochemistry and physiology. Journal of Lipid Research, 54(7).
DOI: https://doi.org/10.1194/jlr.R037648

2006. The acute and chronic toxic effects of vitamin A. American Journal of Clinical Nutrition, 83(2).
DOI: https://doi.org/10.1093/ajcn/83.2.191

2017. Opinion of the Scientific Committee on Consumer Safety (SCCS) - Final version of the Opinion on Vitamin A (retinol, retinyl acetate and retinyl palmitate) in cosmetic products. Regulatory Toxicology and Pharmacology, 84().
DOI: https://doi.org/10.1016/j.yrtph.2016.11.017