Tributyl Citrate
CAS Number: 77-94-1
Product Profile
Tributyl citrate is a biodegradable organic ester synthesized by the esterification of citric acid and n-butanol. Classified as a non-toxic, phthalate-free plasticizer, it boasts exceptional miscibility with a wide range of pharmaceutical film-forming polymers, low volatility and excellent thermal stability, making it a gold-standard auxiliary material for pharmaceutical coating systems.
Within pharmaceutical production, its core function is to act as a high-performance plasticizer for polymeric coating solutions applied to all solid oral dosage forms. When incorporated into coating formulas for tablets, hard gelatin capsules and soft capsules, it effectively increases the flexibility and ductility of the polymer film layer. This eliminates common coating defects such as cracking, peeling and chipping during production, transportation and long-term shelf storage, while also delivering uniform, smooth coating coverage on drug surfaces.
| Tributyl citrate Chemical Properties |
| Melting point | ≥300 °C(lit.) |
| Boiling point | 234 °C (17 mmHg) |
| density | 1.043 g/mL at 20 °C (lit.) |
| Pour Point | -62 |
| refractive index | n20/D 1.445 |
| Fp | 300 °C |
| storage temp. | Store below +30°C. |
| solubility | Miscible with acetone, ethanol, and vegetable oil; practically insoluble in water. |
| pka | 11.30±0.29(Predicted) |
| form | Liquid |
| color | Clear |
| Odor | odorless |
| Water Solubility | insoluble |
| Merck | 14,1564 |
| BRN | 1806072 |
| Cosmetics Ingredients Functions | SOLVENT PLASTICISER FILM FORMING |
| InChI | 1S/C18H32O7/c1-4-7-10-23-15(19)13-18(22,17(21)25-12-9-6-3)14-16(20)24-11-8-5-2/h22H,4-14H2,1-3H3 |
| InChIKey | ZFOZVQLOBQUTQQ-UHFFFAOYSA-N |
| SMILES | CCCCOC(=O)CC(O)(CC(=O)OCCCC)C(=O)OCCCC |
| LogP | 4.324 (est) |
| CAS DataBase Reference | 77-94-1(CAS DataBase Reference) |
| NIST Chemistry Reference | Butyl citrate(77-94-1) |
| EPA Substance Registry System | 1,2,3-Propanetricarboxylic acid, 2-hydroxy-, tributyl ester (77-94-1) |
| Safety Information |
| Hazard Codes | T |
| Risk Statements | 25 |
| Safety Statements | 26-36/37/39-45-24/25 |
| RIDADR | UN 2811 6.1/PG 2 |
| WGK Germany | 3 |
| RTECS | TZ8608000 |
| TSCA | TSCA listed |
| HS Code | 29181500 |
| Storage Class | 10 - Combustible liquids |
Certified Pharmaceutical Secondary Standard Grade
Our supplied tributyl citrate is available as fully certified pharmaceutical secondary reference standards, specially formulated and validated for routine quality control testing in pharmaceutical analytical laboratories and drug manufacturing facilities.
Official pharmacopoeia primary reference standards often come with steep procurement costs and strict limited usage quotas. Our certified secondary standards serve as a reliable, practical and budget-conscious replacement that fully complies with global pharmacopoeia specifications. Every batch undergoes rigorous comparative calibration against official primary standards, ensuring consistent, repeatable and accurate analytical test results. Laboratories can drastically reduce recurring QC testing expenditure without sacrificing data precision or regulatory compliance during raw material inspection, finished product release testing and stability studies.
As a non-toxic, phthalate-free, biocompatible plasticizer compliant with global pharmaceutical compendia, Tributyl Citrate serves as a core functional additive for all types of polymer-based pharmaceutical coating formulations. It delivers outstanding miscibility with common film-forming polymers and effectively softens rigid polymer molecular chains, eliminating coating brittleness, cracking, peeling and flaking issues during production, transportation and long-term storage of oral medicines.
This plasticizer is widely deployed across full-spectrum solid oral drug delivery systems, covering hard gelatin capsules, soft capsules, compressed tablets, spherical drug beads, micro-pellets and pharmaceutical granules. It adapts perfectly to diverse coating functional goals to meet multi-scenario pharmaceutical manufacturing demands:
Taste-masking coating systems
It optimizes the flexibility of barrier polymer films, forming a dense, uniform isolation layer on drug carriers to block bitter, pungent or unpleasant medicinal odors and flavors, improving patient medication compliance without interfering with drug active ingredient release.
Immediate-release coating formulations
It balances film ductility and water permeability of coating layers, enabling rapid water penetration once the oral preparation contacts gastrointestinal fluid, facilitating fast dissolution and quick release of active pharmaceutical ingredients (APIs).
Sustained / controlled-release coating systems
By tuning the elasticity and compactness of rate-controlling polymer membranes, it stabilizes consistent drug diffusion channels, achieving steady, long-lasting API release over preset time periods for extended-action oral drugs.
Enteric-coated formulations
It enhances the mechanical toughness of acid-resistant enteric polymer films, preventing coating breakdown under the acidic environment of gastric fluid. The coating remains intact until reaching neutral intestinal fluid, where it dissolves rapidly to release APIs, protecting acid-sensitive active ingredients from gastric degradation and targeting intestinal absorption.
Beyond its core plasticizing function, Tributyl Citrate features low volatility, excellent thermal stability and biodegradability, and does not trigger adverse interactions with pharmaceutical active substances or excipients. It is the preferred green plasticizer for GMP-standard pharmaceutical coating workshops worldwide.
