Propylene Glycol: Solvent, Humectant and Co-Emulsifier
Propylene glycol (1,2-propanediol) is a clear, viscous, practically odourless liquid that is miscible with water, ethanol, and many organic solvents. It is one of the most widely used excipient solvents in pharmaceutical, cosmetic, and food formulations. Its ability to dissolve both hydrophilic and moderately lipophilic compounds, combined with its antimicrobial preservative-boosting properties, makes it indispensable in liquid and semi-solid dosage forms.
Product Profile
| CAS Number | 57-55-6 |
|---|---|
| Molecular Formula | C₃H₈O₂ |
| Appearance | Clear, colourless, viscous liquid |
| Function | Solvent / humectant / co-emulsifier / preservative enhancer |
| Typical Use Level | 10–30% in topicals; up to 80% in some oral solutions |
| Compendial Grade | EP / USP-NF |
Formulation Applications
In oral liquid formulations, propylene glycol is used as a co-solvent to keep poorly soluble drugs in solution and to reduce water activity, enhancing preservation. In topical creams and gels, it serves as both a humectant (preventing moisture loss) and a penetration enhancer that improves dermal absorption of active ingredients. It is a standard component of injectable vehicles at concentrations typically below 40%. In personal care products, it maintains moisture in lotions and serums. Propylene glycol also functions as a carrier solvent for flavourings and for nicotine in e-liquids.
Why Source from TCS
TCS supplies Propylene Glycol in pharmaceutical and technical grades to formulators across Europe. Available in standard packaging with flexible quantities for R&D through production scale. Contact us with your application and volume requirements.
FAQ
What information should be included in an inquiry for Propylene Glycol –57-55-6?
A useful inquiry normally includes the product name, target application, estimated quantity, destination market, and any specific documentation or packaging requests.
How is Propylene Glycol –57-55-6 usually evaluated for sourcing?
This product is positioned for excipient sourcing where formulation fit, dosage form, handling, and repeat purchasing requirements need to be reviewed together with commercial supply conditions.
What documentation and commercial points are commonly reviewed before buying Propylene Glycol –57-55-6?
For excipient sourcing, teams usually discuss the intended dosage form, formulation role, packaging format, order volume, and the routine documentation needed for qualification and purchasing.
Request a Quote
If your team already has a target application, estimated quantity, destination market, or documentation requirements, send those details so the commercial response can be prepared more efficiently.