Science
Mechanism of Action
As a humectant, PEG-450 attracts and binds water molecules, facilitating prolonged hydration by absorbing atmospheric moisture and gradually releasing it to the skin. It forms a subtle barrier on the skin's surface, which aids in reducing transepidermal water loss. Furthermore, PEG-450 acts as an effective solvent and solubilizer, improving the penetration of co-formulated active ingredients by reducing surface tension and conditioning the stratum corneum.
Research
Clinical Evidence
Medium confidence20%
Key findings
- 01 Polyethylene Glycol (PEG) vehicles, including those with properties corresponding to PEG-450, have demonstrated efficacy in enhancing delivery. A 30% salicylic acid formulation utilizing a PEG vehicle effectively treated comedogenic acne in 75% of cases with minimal irritation, proving suitable for sensitive skin.
- 02 As a base in topical treatments for conditions such as ichthyosis, PEG concentrations typically ranging from 20-30% have shown to reduce scaling and dryness, simultaneously improving skin barrier function.
Transparency
Dusting Analysis
PEG-450 is a key functional ingredient, typically incorporated at substantial percentages (e.g., 20-30% as a vehicle or base) to achieve its humectant, solvent, and delivery-enhancing properties. It is not an ingredient commonly 'dusted' at sub-efficacious concentrations for marketing purposes.
The Formula
Formulation
Stability
Aqueous solutions of PEG-450 are stable at room temperature, with PEG bonds resistant to hydrolysis under these conditions. Dissolving PEG-450 in warm water (80-90 °C) does not adversely affect its integrity. However, PEGs are susceptible to oxidative degradation when exposed to air; this can be minimized by limiting exposure to elevated temperatures and oxygen, or by incorporating antioxidants.
Conflicts
- Phenol (may reduce antimicrobial action)
- Other preservatives (may reduce antimicrobial action)
- Penicillin (rapidly inactivated)
- Bacitracin (rapidly inactivated)
- Sorbitol
- Tannic acid
- Salicylic acid
- Plastics (may affect integrity)
- Compounds with hydroxyl groups (can react to form degradation products)
- Compounds susceptible to auto-oxidation (PEGs can cause degradation)
Safety
Safety Profile
The CIR Expert Panel has determined PEG-450 to be safe for use in cosmetics on intact skin, exhibiting low oral and dermal toxicity. Higher molecular weight PEGs, including PEG-450, are minimally absorbed through intact skin, which limits systemic exposure. It is considered minimally irritating, non-sensitizing, non-mutagenic, and non-carcinogenic. While kidney toxicity has been reported in severely burned patients treated with PEG-based antimicrobial creams, no evidence of systemic toxicity has been observed in studies involving intact skin. Trace amounts of 1,4-dioxane, a by-product of ethoxylation, are present but are rigorously controlled and do not pose a health risk as concluded by the FDA and SCCS.
Your Skin
Skin Compatibility
Our Assessment
Verdict
PEG-450 is a valuable multi-functional ingredient, safely enhancing skin hydration and optimizing the delivery of other actives across all skin types, provided specific formulation incompatibilities are carefully managed.
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