Triacetin

Triacetin ^[1]

Names
Systematic IUPAC name Propane-1,2,3-triyl triacetate
Other names Glycerol triacetate glycerin triacetate 1,2,3-triacetylglycerol 1,2,3-triacetoxypropane
Identifiers
CAS Number	102-76-1  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:9661  N
ChEMBL	ChEMBL1489254  N
ChemSpider	13835706  Y
ECHA InfoCard	100.002.775
EC Number	203-051-9
E number	E1518 (additional chemicals)
KEGG	D00384  Y
PubChem CID	5541
RTECS number	AK3675000
UNII	XHX3C3X673  Y
CompTox Dashboard (EPA)	DTXSID3026691
InChI InChI=1S/C9H14O6/c1-6(10)13-4-9(15-8(3)12)5-14-7(2)11/h9H,4-5H2,1-3H3 Y Key: URAYPUMNDPQOKB-UHFFFAOYSA-N Y InChI=1/C9H14O6/c1-6(10)13-4-9(15-8(3)12)5-14-7(2)11/h9H,4-5H2,1-3H3 Key: URAYPUMNDPQOKB-UHFFFAOYAH
SMILES CC(=O)OC(COC(=O)C)COC(C)=O
Properties
Chemical formula	C9H14O6
Molar mass	218.205 g·mol−1
Appearance	Oily liquid
Density	1.155 g/cm3 [2]
Melting point	−78 °C (−108 °F; 195 K) [3] : 3–534
Boiling point	259 °C (498 °F; 532 K) [3] : 3–534
Solubility in water	6.1 g/100 mL [4] [ page needed ]
Solubility in ethanol	Miscible
Solubility in benzene	soluble
Solubility in diethyl ether	soluble
Solubility in acetone	very soluble
Vapor pressure	1 Pa (0.0075 mmHg) (37.6 °C (99.7 °F; 310.8 K)) 10 Pa (0.075 mmHg) (62 °C (144 °F; 335 K)) 100 Pa (0.75 mmHg) (90 °C (194 °F; 363 K)) 1 kPa (7.5 mmHg) (124 °C (255 °F; 397 K)) 10 kPa (75 mmHg) (165 °C (329 °F; 438 K)) 100 kPa (750 mmHg) (214 °C (417 °F; 487 K)) [3] : 6–88
Refractive index (nD)	1.4301 (20 °C (68 °F; 293 K)) [3] : 3–534
Viscosity	23 mPas (20 °C (68 °F; 293 K)) [2]
Thermochemistry [5] [3] : 6–121
Heat capacity (C)	389 J⋅mol−1·K-1
Std molar entropy (S⦵298)	458.3 kJ⋅mol−1·K-1
Std enthalpy of formation (ΔfH⦵298)	−1330.8 kJ⋅mol−1
Std enthalpy of combustion (ΔcH⦵298)	4211.6 kJ⋅mol−1
Enthalpy of vaporization (ΔfHvap)	85.74 kJ⋅mol−1
Hazards [2]
NFPA 704 (fire diamond)	0 1 0
Flash point	138 °C (280 °F; 411 K)
Autoignition temperature	430 °C (806 °F; 703 K)
Explosive limits	7.73%-?
Lethal dose or concentration (LD, LC):
LD50 (median dose)	3 g/kg (rat, oral) [2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

Triacetin is the organic compound with the formula C₃H₅(OCOCH₃)₃. It is classified as a triglyceride, i.e., the triester of glycerol with acetic acid. It is a colorless, viscous, and odorless liquid with a high boiling point and a low melting point. It has a mild, sweet taste in concentrations lower than 500 ppm, but may appear bitter at higher concentrations. ^[6] It is one of the glycerine acetate compounds.

Uses

Triacetin is a common food additive, for instance as a solvent in flavorings, and for its humectant function, with E number E1518 and Australian approval code A1518. It is used as an excipient in pharmaceutical products, where it is used as a humectant, a plasticizer, and as a solvent. ^[7]

Potential uses

The plasticizing capabilities of triacetin have been utilized in the synthesis of a biodegradable phospholipid gel system for the dissemination of the cancer drug paclitaxel (PTX). ^[8] In the study, triacetin was combined with PTX, ethanol, a phospholipid and a medium chain triglyceride to form a gel-drug complex. This complex was then injected directly into the cancer cells of glioma-bearing mice. The gel slowly degraded and facilitated sustained release of PTX into the targeted glioma cells.

Triacetin can also be used as a fuel additive as an antiknock agent for gasoline, and to improve low-temperature viscosity properties of biodiesel. ^[9]

It has been considered as a possible source of food energy in artificial food regeneration systems on long space missions. It is believed to be safe to get over half of one's dietary energy from triacetin. ^[10]

Synthesis

Triacetin was first prepared in 1854 by the French chemist Marcellin Berthelot. Triacetin was prepared in the 19th century from glycerol and acetic acid. ^{[11] [12]}

Its synthesis from acetic anhydride and glycerol is simple and inexpensive:

3 (CH₃CO)₂O + C₃H₅(OH)₃ → C₃H₅(OCOCH₃)₃ + 3 CH₃CO₂H

This synthesis has been conducted with catalytic sodium hydroxide and microwave irradiation to give a 99% yield of triacetin. ^[13] Synthesis has also been conducted with a cobalt(II) Salen complex catalyst supported by silicon dioxide and heated to 50 °C (122 °F) for 55 minutes to give a 99% yield of triacetin. ^[14]

Safety

The US Food and Drug Administration has approved it as generally recognized as safe food additive and included it in the database according to the opinion from the Select Committee On GRAS Substances (SCOGS). Triacetin is included in the SCOGS database since 1975. ^{[15] [16]}

Triacetin was not toxic to animals in studies of exposure through repeated inhalation over a relatively short period. ^[17]

References

1. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.). Merck. 1989. p. 9405. ISBN   091191028X.
2. "Triacetin SDS". fishersci.com. ThermoFisher Scientific. Retrieved 2025-12-05.
3. Lide D, ed. (2004). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN   978-0-8493-0485-9.
4. Lide DR, ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN   978-1-4200-9084-0.
5. Triacetin in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD)
6. Arctander S (1969). Perfume and Flavor Chemicals (II K - Z). Elizabeth, N.J.: Published by the Author. p. 2971. ISBN   978-0-931710-37-7.
7. "Triacetin". drugtopics.modernmedicine.com. Advanstar Communications, Inc. Archived from the original on 2012-02-19. Retrieved 2014-06-20.
8. Chen T, Gong T, Zhao T, Liu X, Fu Y, Zhang Z, et al. (August 2017). "Paclitaxel loaded phospholipid-based gel as a drug delivery system for local treatment of glioma". International Journal of Pharmaceutics. 528 (1–2): 127–132. doi:10.1016/j.ijpharm.2017.06.013. PMID   28596136.
9. Gupta M, Kumar N (2012). "Scope and opportunities of using glycerol as an energy source". Renewable & Sustainable Energy Reviews. 16 (7): 4551–4556. Bibcode:2012RSERv..16.4551G. doi:10.1016/j.rser.2012.04.001.
10. Shapira J, Mandel AD, Quattrone PD, Bell NL (1968). "Current Research On Regenerative Systems" (PDF). Life Sciences in Space Research. 7. Tokyo: Committee On Space Research, Eleventh Annual Meeting: 123–9. PMID   12197534 . Retrieved 2024-07-16.
11. Berthelot M (1854). "Sur les combinaisons de le glycérine avec les acides et sur la synthèse des principes immédiats des graisses des animaux" [On the compounds of glycerin with acids and on the synthesis of immediate principles of animal fats]. Annales de Chimie et de Physique. 3rd series (in French). 41: 216–319.
12. "Preparation of glyceryl triacetate". Journal of the Chemical Society, Abstracts. 38: 312. 1880. doi:10.1039/CA8803800307.
13. Rajabi F, Saidi MR (2005). "A Cheap, Simple, and Versatile Method for Acetylation of Alcohols and Phenols and Selective Deprotection of Aromatic Acetates Under Solvent-Free Condition". Synthetic Communications. 35 (3): 483–491. doi:10.1081/SCC-200048988. ISSN   0039-7911. S2CID   96001761.
14. Rajabi F (2009). "A heterogeneous cobalt(II) Salen complex as an efficient and reusable catalyst for acetylation of alcohols and phenols". Tetrahedron Letters. 50 (4): 395–397. doi:10.1016/j.tetlet.2008.11.024.
15. "21 CFR § 184.1901 Listing of Specific Substances Affirmed as GRAS: Triacetin". eCFR.gov. FDA. 21 Feb 1989. Retrieved 25 Apr 2023.
16. "Glycerin and Glycerides". www.fda.gov. U.S. Food and Drug Administration. Archived from the original on 2017-10-31. Retrieved 2014-06-20. Triacetin and two types of acetooleins have been found to be without toxic effects in long-term feeding tests in rats at levels that were several orders of magnitude greater than those to which consumers are exposed.
17. Fiume MZ (2003). "Final report on the safety assessment of triacetin". International Journal of Toxicology. 22 Suppl 2 (3): 1–10. doi:10.1080/747398359. PMID   14555416.