درس3: انواع ترکیبات مرطوب‌کننده

    Here is a categorized list of chemical and natural moisturizing compounds commonly found in cosmetics, with a          brief explanation of their functions. Sources for this information are included to validate the claims.
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    1. Humectants
    Function: Attract and retain water in the skin.
    • Glycerin: A natural compound that pulls water into the skin, effective even at high concentrations. It's widely            used for barrier repair and hydration.
    • Hyaluronic Acid and Sodium Hyaluronate: Large molecules that act as moisture sponges. Sodium hyaluronate            penetrates deeper into the skin than hyaluronic acid.
    • Urea: Found naturally in the skin, it hydrates and exfoliates mildly.
    • Propanediol: Derived from corn sugar, it works as a humectant and solvent, often replacing propylene glycol.
    • Aloe Vera: Contains polysaccharides that draw water to the skin while providing soothing benefits.
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     2. Emollients
     Function: Smooth and soften the skin by filling gaps between skin cells.
    • Shea Butter: A rich fat extracted from the shea tree, used for deep nourishment.
    • Cocoa Butter: Provides intensive hydration and is suitable for very dry skin.
    • Jojoba Oil: Mimics natural sebum, offering lightweight moisturizing benefits.
    • Cetyl Alcohol and Stearyl Alcohol: Fatty alcohols that soften skin without the drying effects of regular alcohols.
    • Caprylic/Capric Triglyceride: Derived from coconut oil and glycerin, it's lightweight and non-greasy.
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    3. Occlusives
    Function: Create a barrier to lock in moisture.
    • Petrolatum: The gold standard for occlusives, it prevents up to 99% of transepidermal water loss (TEWL).
    • Lanolin: A natural wax from sheep's wool, it seals moisture effectively.
    • Dimethicone: A lightweight silicone that forms a barrier without clogging pores.
    • Beeswax: Naturally derived and effective for creating a water-repelling barrier.
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    4. Skin-Identical Compounds
    Function: Mimic the skin’s natural components for barrier repair and hydration.
    • Ceramides: Lipids essential for maintaining a healthy skin barrier. They are effective in formulations targeting            dry or damaged skin【9】.
    • Cholesterol: Works synergistically with ceramides to restore barrier function【9】.
    • Sodium PCA: Naturally found in the skin, it helps retain moisture【9】.
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    5. Antioxidant Moisturizers
    Function: Provide hydration while protecting the skin from environmental damage.
    • Vitamin E (Tocopherol): An oil-soluble antioxidant that protects and hydrates.
    • Niacinamide: Vitamin B3 that improves barrier function and hydration while reducing inflammation.
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    Natural Ingredients
    Function: Plant-based or organic sources for hydration and nourishment.
    • Coconut Oil: Provides deep hydration but may be too heavy for oily or acne-prone skin.
    • Avocado Oil: Rich in fatty acids and vitamins for nourishing dry or sensitive skin.
    • Honey: Acts as a natural humectant, attracting and retaining moisture.