A-Leen 8 is the neat, undiluted version of caprylyl glycol, distinguishing it from the stabilized liquid form (E-Leen 8). It provides broad-spectrum antimicrobial activity by disrupting microbial cell membrane integrity. Due to its non-ionic nature, its effect is largely pH-independent. Its amphiphilic structure—a hydrophilic diol group linked to a hydrophobic tail—enables it to bind water to the skin surface effectively.
Key Benefit: A high-purity preservation “anchor” that significantly enhances the solubilization of difficult polyphenolic actives like quercetin and salicylic acid.
Performance & Multifunctional Benefits
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Antimicrobial Efficacy: At 0.5% alone in an O/W emulsion (pH 5.5), it meets ISO 11930 Criteria A. However it is used as part of a hurdle approach rather than a solo broad spectrum protector.
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Synergy Blueprint: Combining it with Phenylpropanol (A-Leen Aroma-3) achieves Criteria A with enhanced antifungal results at a lower total concentration.
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Active Solubilization: Comparative HPLC data shows that pairing it with Pentylene Glycol (A-Leen 5) significantly boosts the solubility of polyphenols.
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Skin Hydration: Corneometry confirms a statistically significant increase in skin hydration for up to 4 hours after a single application.
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Surface Activity: Acts as a mild wetting agent for pigment particles and surfaces.
Formulation & Handling Guidelines
A-Leen 8 requires heat for incorporation and careful monitoring of solubility limits.
It is fully miscible with ethanol and C3–C6 alkanediols, and shows good solubility in polar vegetable oils (e.g. 50% in caprylic/capric triglyceride and dicaprylyl ether). It dissolves well in surfactant-based products. In emulsions, it is preferably added at the post-emulsification stage for optimum antimicrobial efficacy. Formulators should note that its weak surface activity may influence the viscosity of gels and emulsions
