Tributyl acetylcitrate (TBC) is a plasticizer belonging to the citrate ester family, widely used to enhance the flexibility, durability, and processability of polymers, especially polyvinyl chloride (PVC). Developed as a safer and more environmentally friendly alternative to traditional phthalate plasticizers, TBC gained attention in the mid-20th century due to concerns over toxicity and environmental persistence associated with phthalates. Its low volatility, biodegradability, and non-toxic profile made it particularly suitable for applications in food contact materials, medical devices, toys, and flexible packaging, where human exposure could occur. Over the decades, TBC has become an important plasticizer in industries seeking high-performance and safer polymer products.
BRAND NAMES
Citroflex™ A-4 is a well-known brand produced by the company Aurorium (formerly Vertellus). It is used as a low-toxicity plasticizer in food packaging, medical devices, and toys.
CITROFOL® BII is a brand manufactured by Jungbunzlauer. This is another popular citric acid ester used as a plasticizer in sensitive applications like medical products, food packaging, and cosmetics.
HallStar® ATBC is a product from the company Hallstar and is used as a film-forming plasticizer in cosmetics like nail polish and long-lasting makeup.
KANATOL - 3400AC is a brand of ATBC from the KLJ Group, primarily used as a plasticizer for PVC in applications such as food packaging and medical products.
NatureFlexx 509 is a brand manufactured by The Chemical Company (TCC). It is used as an eco-friendly plasticizer in products like food packaging and soft toys.
ALCANPLAST ATBC is a brand name distributed by Safic-Alcan.
HARIOL ATBC is a brand of acetyl tributyl citrate produced by Subhash Chemical Industries in India.
MECHANISM OF ACTION
Tributyl acetylcitrate (TBAC) acts primarily as a plasticizer, increasing the flexibility of polymers like PVC. It works by inserting itself between polymer chains, reducing intermolecular forces and allowing the chains to slide past each other more easily. This physical “lubrication” makes materials softer and less brittle. TBAC is also biodegradable and non-toxic, breaking down into citric acid and butanol, and does not have a pharmacological mechanism of action.
PHARMACOKINETICS
Absorption
Tributyl acetylcitrate (ATBC) is quickly absorbed, exhibiting a bioavailability of approximately 27.4% in rats, and is rapidly metabolized and excreted. Although it is utilized in pharmaceutical coatings, its pharmacokinetics are still under investigation. ATBC is generally insoluble in water but dissolves readily in most organic solvents.
Distribution
Studies have estimated the volume of distribution of tributyl acetylcitrate (ATBC) in rats to be 80.4 L/kg following intravenous administration. This value exceeds total body water, suggesting that ATBC distributes extensively into tissues, likely due to its high lipid solubility.
Metabolism
Tributyl acetylcitrate (ATBC) is mainly metabolized via hydrolysis, producing intermediates such as acetyl citrate, monobutyl citrate, dibutyl citrate, acetyl monobutyl citrate, and acetyl dibutyl citrate. These metabolites are predominantly excreted in urine and feces, with a minor amount eliminated in expired air, and the metabolism occurs rapidly after administration.
Excretion
Tributyl acetylcitrate (ATBC) is primarily excreted via urine and feces following metabolism. A small portion is also eliminated in expired air. Most of the compound is rapidly metabolized through hydrolysis before excretion.
PHARMACODYNAMICS
Tributyl acetylcitrate (ATBC) does not have classical pharmacodynamics like a drug because it is not pharmacologically active. Its main role is as a plasticizer in pharmaceutical coatings and materials. In this context, its “effect” is physical rather than biochemical: it inserts between polymer chains, reducing intermolecular forces and increasing flexibility and softness. ATBC is considered biologically inert, with no known receptor interactions or direct physiological effects.
ADMINISTRATION
Tributyl acetylcitrate (ATBC) is used as a pharmaceutical coating for oral dosage forms such as tablets and capsules, serving as an excipient. In animal pharmacokinetic studies, it has been administered orally to examine its absorption, metabolism, and elimination.
DOSAGE AND STRENGTH
Tributyl acetylcitrate (ATBC) is not used as a therapeutic drug, so it does not have a conventional dosage or strength. Its use is primarily as a pharmaceutical excipient or plasticizer, for example in coatings of tablets and capsules. In these applications, the amount used depends on the formulation requirements to achieve desired flexibility, stability, or release properties, rather than a pharmacological dose.
FOOD INTERACTIONS
Tributyl acetylcitrate (ATBC) is considered safe for use in food and food-contact materials, with no significant interactions with food or nutrients. It is largely inert, rapidly metabolized, and excreted, and any migration into fatty foods is minimal, making it low-risk under normal use.
DRUG INTERACTIONS
Tributyl acetylcitrate (ATBC) has no known drug interactions, as it is an inactive excipient rather than an active pharmaceutical ingredient. It does not affect drug-metabolizing enzymes or transporters and is rapidly metabolized and eliminated. Therefore, ATBC is considered pharmacologically inert and unlikely to interfere with the action or metabolism of other drugs.
CONTRAINDICATIONS
Tributyl acetylcitrate (ATBC) has no specific contraindications, as it is used as an inactive excipient and not as a therapeutic drug. It is generally regarded as safe and non-toxic at levels used in pharmaceuticals and food packaging. However, individuals with known hypersensitivity to citrate esters or related compounds should avoid exposure as a precaution.
SIDE EFFECTS
Irritation.
Gastrointestinal issues.
Neurological effects.
Skin irritation.
Oxidative stress and inflammation in brain tissue.
Aggravated glycolipid metabolic disorders.
OVERDOSE
Ingestion.
Metabolic and fatty liver disease.
Reproductive effects.
Exacerbated effects in diabetes.
Potential carcinogenic effects.
TOXICITY
Acetyl tributyl citrate (ATBC) exhibits low acute toxicity, but adverse effects may occur at high doses or in sensitive individuals. Research indicates that ATBC can worsen glycolipid metabolism disorders and induce cognitive impairments in mice with type 2 diabetes, even at doses considered safe for healthy mice. Additionally, it may affect ovarian follicles at doses around 10 mg/kg/day, though overall studies suggest it is not a developmental or reproductive toxicant.
