New alternatives to cosmetics preservation

Area of Science:

• Cosmetic Science
• Microbiology
• Natural Product Chemistry

Background:

• Growing consumer demand for preservative-free cosmetics drives innovation in alternative preservation systems.
• Traditional chemical preservatives face regulatory scrutiny and consumer concerns regarding potential health effects.
• Developing effective self-preserving cosmetic formulations is crucial for product safety and market acceptance.

Purpose of the Study:

• To evaluate the efficacy of cosmetic formulations preserved with natural antimicrobial agents, specifically Lonicera extracts.
• To assess the combined preservative effects of Lonicera extracts with glyceryl caprylate, levulinic acid, p-anisic acid, and ethanol.
• To determine the microbiological safety of these formulations under both laboratory challenge conditions and consumer use scenarios.

Main Methods:

• Preparation of various cosmetic formulations (tonic lotion, shampoo, shower gel, creams) with Lonicera caprifoleum and Lonicera japonica extracts.
• Application of European Pharmacopoeia challenge tests to assess preservative efficacy against microbial contamination, including Aspergillus niger.
• Evaluation of product safety during simulated consumer use to assess long-term microbiological stability.

Main Results:

• Formulations containing Lonicera extracts and glyceryl caprylate met preservative criteria (Criterion A or B) for Aspergillus niger.
• Products meeting only Criterion B showed microbial growth during consumer use, indicating insufficient preservation.
• Incorporation of levulinic acid, p-anisic acid, and/or ethanol significantly enhanced preservative efficacy, achieving Criterion A and ensuring safety during use.

Conclusions:

• Lonicera extracts combined with glyceryl caprylate offer a foundation for self-preserving cosmetics.
• Antimicrobial additives like levulinic acid, p-anisic acid, and particularly ethanol, are essential for robust and stable preservative systems.
• These natural preservation strategies provide a viable alternative to traditional chemical preservatives, ensuring product safety and efficacy.