Diethanolamine (DEA, CAS 111-42-2) is a secondary alkanolamine that plays a modest but important role in pharmaceutical formulation. It is rarely the active ingredient; instead, it is used as a processing and performance aid that helps other ingredients behave correctly. Understanding what DEA does, which grades are available and how quality is controlled helps formulators and buyers make informed decisions.
Diethanolamine at a Glance
| Property | Value |
| Chemical name | 2,2'-Iminodiethanol (diethanolamine) |
| CAS number | 111-42-2 |
| Molecular formula | C4H11NO2 |
| Molecular weight | 105.14 g/mol |
| Appearance | Colorless to pale yellow liquid or crystalline solid |
| Boiling point | Approx. 268.8 °C |
| Flash point | Approx. 138 °C (closed cup) |
| Density | Approx. 1.097 g/cm3 at 20 °C |
| Solubility | Miscible with water; soluble in alcohols and acetone |
Key Pharmaceutical Functions
pH adjustment and neutralization: DEA neutralizes acidic actives and excipients, helping formulations reach a target pH that supports stability and bioavailability.
Emulsification: In creams, lotions and ointments, DEA can act as an emulsifying aid, improving the uniformity and stability of oil-in-water systems.
Salt and complex formation: It can form salts or complexes with certain acidic drugs, modifying solubility or stability to aid formulation.
Buffering: In combination with appropriate acids, DEA contributes to buffering systems that keep pH within a defined range during storage.
Grades and Quality Control
DEA is supplied in industrial, cosmetic and pharmaceutical-relevant grades. For pharma-adjacent applications, buyers should request specification sheets covering assay (typically 99% or higher), water content, color (APHA), and limits for related amines such as monoethanolamine and triethanolamine. Because secondary amines can form nitrosamines under certain conditions, responsible manufacturers and distributors control precursors and document impurity profiles. Batch-specific certificates of analysis (COA) should accompany every delivery.
Regulatory and Safety Considerations
DEA is classified under GHS with hazard statements including H302 (harmful if swallowed), H315 (skin irritation), H318 (serious eye damage) and H335 (respiratory irritation). It is also covered by chemical inventory and use regulations in major markets, so buyers must verify that the grade, end use and quantities comply with applicable rules. Handle DEA with gloves and eye protection, and store it in sealed containers because it is hygroscopic and can absorb carbon dioxide from air over time.
Sourcing and Supply Considerations
For bulk pharmaceutical-adjacent use, look for suppliers with ISO 9001 quality systems, consistent assay and impurity data, secure packaging (drums or IBC totes) and documented export compliance. Confirm the water content and color on arrival and check that the COA matches the batch number on the container. Reliable logistics partners keep transit time short because prolonged exposure to moisture can degrade quality.
Frequently Asked Questions
What is DEA used for in medicines? DEA is mainly a formulation aid: it adjusts pH, helps emulsify creams and ointments, and can form salts with acidic drugs to improve solubility and stability. It is not typically the active pharmaceutical ingredient.
What is the difference between MEA, DEA and TEA? Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) are ethanolamines with one, two and three hydroxyl groups respectively. They differ in basicity, hygroscopicity and typical uses; DEA sits between MEA and TEA in molecular weight and reactivity.
Is DEA safe in pharmaceutical products? When used at approved levels in approved product types and manufactured to appropriate quality standards, DEA is accepted in regulated formulations. Any specific product must still satisfy the requirements of the relevant regulatory authority for that market.
How is DEA quality verified? Through specification testing - assay, water content, color, related amines, and impurity limits - documented in a batch certificate of analysis issued against an agreed specification.
How should DEA be stored? Store in tightly sealed containers in a cool, dry place, protected from moisture and carbon dioxide. Avoid contact with strong acids and oxidizers.
Can DEA be used in injectable products? Suitability for any specific dosage form depends on the formulation, the regulatory framework and the manufacturer's approval. Always verify acceptability with qualified formulation and regulatory experts.