Science
Mechanism of Action
Polysorbate 40 operates by reducing interfacial tension between immiscible phases, thereby stabilizing emulsions and solubilizing oil-based components in water-based systems. As a surfactant, it facilitates the removal of impurities and aids in the dispersion of active ingredients. Its micellarization capabilities can also enhance the delivery and bioavailability of certain insoluble compounds by improving wettability.
Research
Clinical Evidence
Medium confidence0.5% to 2.0%
Key findings
- 01 Demonstrated enhanced drug release, such as loratadine, attributed to improved wettability and micellarization at the drug-vehicle interface. Concentrations around 2% showed a reduced extent of release, indicating critical micelle formation.
- 02 Effective in stabilizing quercetin-loaded Solid Lipid Nanoparticles (SLNs), leading to an observed increase in hydration effect.
Transparency
Dusting Analysis
Polysorbate 40 is primarily a functional excipient for emulsion stability and solubilization, not an active ingredient typically 'dusted' at low, ineffective concentrations. Its efficacy is tied to its role in formulation mechanics, and concentrations are guided by desired physical properties and safety limits rather than marketing claims.
The Formula
Formulation
Stability
Polysorbate 40 is stable with electrolytes, weak acids, and weak bases, although strong acids and bases can cause gradual saponification. Its oleate component is prone to oxidation, and the substance is hygroscopic. Prolonged storage may lead to peroxide formation. Optimal stability is maintained by storing in a sealed container, away from light, in a cool and dry environment. It is compatible with a wide range of pH levels and temperatures due to its nonionic nature.
Synergies
- Oil and water phases (for emulsification)
- Essential and fragrance oils (for solubilization)
- Active ingredients (for enhanced dispersion and delivery)
Conflicts
- Strong acids
- Strong bases (saponification)
- Phenol (discoloration/precipitation)
- Tannin (discoloration/precipitation)
- Tar and tar-like substances (discoloration/precipitation)
- Parabens (reduces antimicrobial activity)
- Potential contaminants like 1,4-dioxane and ethylene oxide (if improperly manufactured)
Safety
Safety Profile
The CIR Expert Panel considers polysorbates, including Polysorbate 40, safe for use in cosmetics at current concentrations when formulated to be non-irritating. The WHO sets an acceptable daily intake of 0-25 mg/kg body weight for polyoxyethylene (20) sorbitan esters. The FDA generally recognizes Polysorbate 40 as safe (GRAS) for food use and as an 'inactive ingredient' in topical pharmaceuticals. However, improper manufacturing can result in impurities like 1,4-dioxane and ethylene oxide, which are potential carcinogens. While generally gentle and non-irritating, some individuals may experience allergic reactions, skin rashes, itching, or swelling, with rare instances of contact dermatitis or anaphylactic reactions. It is considered non-sensitizing.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Polysorbate 40 is a valuable excipient that enhances formula stability, solubilizes key ingredients, and may support active delivery, provided it is properly manufactured and incorporated into non-irritating concentrations up to 6.0%.
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References
Sources