Science
Mechanism of Action
PEI-2500 operates through strong electrostatic interactions, readily binding to negatively charged substrates due to its numerous positive charges. This mechanism is theorized to facilitate film formation and provide conditioning effects on the skin surface, mirroring its known role in hair care where it enhances the adhesion of conditioning agents to hair keratin. Furthermore, its capabilities include promoting the internalization of active compounds in co-delivery systems and exhibiting antibacterial and antifouling properties.
Research
Clinical Evidence
Low confidenceN/A
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Linear polyethyleneimine is soluble in hot water, methanol, ethanol, or chloroform, and specifically requires a pH below 2.0 for initial dissolution. It is insoluble in cold water, benzene, ethyl ether, and acetone. For practical use, solutions are typically prepared by dissolving the polymer at low pH (e.g., below 2.0) and then adjusting to a neutral pH range (approximately 6.9-7.1). Self-assembly into micron-sized fibrils has been observed between pH 2.5-4.0, which could impact formulation characteristics. PEI is almost entirely protonated at pH 2 and minimally protonated at pH 10.
Conflicts
- anionic ingredients
Safety
Safety Profile
There is currently no direct Cosmetic Ingredient Review (CIR) report specifically for Polyethylenimine (PEI) for cosmetic use. While Polyethylenimine is approved by the FDA for certain biomedical applications, its safety in clinical contexts, including topical use, is highly variable based on molecular weight, chemical structure, and concentration. High molecular weight PEI has been associated with increased cytotoxicity, potentially causing cell damage via membrane destabilization or inducing apoptotic cell death by forming pores in mitochondrial membranes. Modifications, such as conjugation with other polymers, are frequently employed to mitigate these toxicity concerns, underscoring the need for specific safety assessments for PEI-2500 in cosmetic applications.
Your Skin
Skin Compatibility
Our Assessment
Verdict
PEI-2500, a cationic polymer, shows potential as a skin conditioning and film-forming agent with possible drug delivery enhancement; however, its absence of dedicated cosmetic safety reviews and general concerns regarding PEI cytotoxicity necessitate rigorous, specific evaluation for safe skincare application.
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