Comedogenicity in rabbit: some cosmetic ingredients/vehicles
Shawn H Nguyen1, Thao P Dang, Howard I Maibach
1Dermatology Department, University of California at San Francisco Medical School, San Francisco, California 94143-0989, USA.
Cutaneous and Ocular Toxicology
|December 7, 2007
Summary
This study identified nine cosmetic ingredients, including isopropyl palmitate and cocoa butter, that cause comedones in rabbits. These findings help assess the comedogenic potential of topical formulations.
Area of Science:
- Dermatology
- Cosmetic Science
- Toxicology
Background:
- Comedones are a common skin concern.
- Assessing the comedogenic potential of cosmetic ingredients is crucial for product safety.
- The rabbit ear assay is a recognized method for evaluating follicular hyperkeratosis.
Purpose of the Study:
- To identify chemicals that cause comedone formation upon topical application.
- To quantify the comedogenic potential of various cosmetic raw materials.
- To provide data for the clinical relevance of ingredient-induced comedogenesis.
Main Methods:
- Utilized the rabbit external ear canal model for topical application testing.
- Evaluated a list of cosmetic ingredients for their ability to induce comedones.
- Included common ingredients like isopropyl palmitate, cocoa butter, and sodium lauryl sulfate (SLS).
Main Results:
- Nine of the tested cosmetic ingredients were found to be comedogenic.
- Positive ingredients included isopropyl palmitate, isopropyl myristate, butyl stearate, isopropyl isostearate, decyl oleate, isostearyl neopentanoate, isocetyl stearate, myristle myristate, and cocoa butter.
- Factors contributing to clinical relevance were also identified.
Conclusions:
- Several commonly used cosmetic ingredients possess comedogenic potential.
- The rabbit ear assay effectively identifies ingredients likely to cause comedones.
- Findings support the assessment of ingredient safety in topical cosmetic formulations.
