Cosmetics and Cosmeceuticals BY: MOHAMMED ALSAIDAN
Facts • A cosmeceutical is a scientifically designed, useful product intended for external application to the human body that has desirable aesthetic effects and meets rigid chemical, physical and medical standards • Acosmetic is defined by the US Federal Food, Drug and Cosmetic Act, written in 1938, as : “articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body or any part thereof for cleansing, beautifying, promoting attractiveness, or altering the appearance”, without affecting structure or function
Facts • Non-prescription topical agents, can penetrate the stratum corneum and influence skin function • Many substances can function as cosmeceuticals if entry into and through the stratum corneum is facilitated via the use of penetration enhancers, such as propylene glycol, isopropyl myristate, and pyrrolidone derivatives
Penetration enhancers • Propylene glycol profoundly alters the barrier characteristics of the stratum corneum • Isopropyl myristateis capable of penetrating into the lipid bilayer of cell membranes. • Pyrrolidonederivatives interact with both keratin and stratum corneum lipids to drive substances into the skin
Skin care products • Cleansers • Astringents • Moisturizers
Skin care products • Cleansers: remove sebum, desquamating corneocytes, bacteria, fungi and environmental dirt from the face and body, while leaving the intercellular lipid barrier intact • Astringents: a subset of cleansers designed to supplement the failure of the cleanser to perform its intended function. • Moisturizers : minimize the barrier damage induced by cleansing. • These three skin care products work together to balance the hygieneneeds of the skin with the important task of preserving barrier function.
Cleanser • The development of soaps has been the single most important advance in decreasing disease worldwide. • Soap is a fatty acid salt resulting from a reaction between a fat and an alkali. • The soap solubilizes sebum and environmental dirt, such that it can be rinsed away with water results in the physical removal of skin scale, bacteria and fungi from the skin surface • Xerosis lead to the development of cleansers with skin conditioning benefits that are chemically not true soaps, and they are referred to as detergents • Cleansers, whether formulated as bars or liquids
Cleanser • Can be divided into three basic types: • Soaps • combars • Syndets
True soaps • Good cleansing choice for excessively oily or dirty skin • long-chain fatty acid alkali salts with alkalinpH between 9 and 10, resulting in stratum corneumbarrier disruption and the resultant feeling of tightness following bathing.
Combar • Good cleanser for normal skin with a moderate amount of environmental dirt. • An alkaline soap to which surface active agents with a pH of 9–10 , • Milder cleansers than true soaps, but induce more thorough cleansing than syndets.
Syndets • Also known as beauty cleansers • Syndets is the least damaging to the cutaneous barrier in persons with dry skin or any form of dermatitis • Contain less than 10% soap • pH of 5.5–7.0 in order to minimize cutaneous alkalinization • E.g. sodium cocoylisethionate
Cleanser • Common cleanser additives include fragrances and foaming agents • The most dermatologically relevant additives are antibacterial agents • The most widely used antibacterial in both bar and liquid cleansers is triclosan(works by blocking lipid synthesis in the bacterial cell wall, thus decreasing the skin bacteria count and reducing odor)
Cleanser • Surfactants cannot distinguish between unwanted sebum and oil-soluble dirt and the intercellular lipids • An attempt to provide cleansing and barrier restoration in the same product has led to the development of body washes.
Cleanser • Body washes • They are liquids, incorporating both hydrophilic and lipophilic ingredients • Allowing to cleanse and moisturize simultaneously while allowing for rinsing away of the surfactants. • Other cleanser variants for persons with dry, dermatitic skin include lipid-free, non-foaming cleansers and cold creams • These products are excellent at removing cosmetics and low levels of environmental dirt
Cleanser • Lipid-free cleansers are non-foaming, soap-free liquid products applied to dry or moistened skin • They possess low surfactant capabilities, and they can only remove bacteria through mechanical means, yet they are important in persons with barrier disruption • cold cream,: The classic cleanser for dry, dermatitic skin is which combines the effect of a lipid solvent, such as wax or mineral oil, with detergent action from borax
Cleanser • exfoliant cleanser that contain salicylic acid or glycolic acid will induce corneocytedisadhesion • Exfoliantcleansers containing benzoyl peroxide or salicylic acid are sometimes used as an adjunct in topical acnetreatment • Exfoliation can also be induced mechanically through the incorporation of fine abrasive particles in a liquid syndet cleanser to remove skin scale (such as polyethylene beads, aluminum oxide, ground fruit pits) • mechanical exfoliation can be encouraged through the use of specially woven face cloths
Moisturizer • The optimal water content for the stratum corneum is between 10% and 30%, • Moisturizers replenishing the stratum corneummoisture by water movement from the lower viable epidermal and dermal layers • The most effective occlusive moisturizer is petrolatum, since it reduces transepidermal water loss by 99% • Petrolatum allows barrier repair while permeating throughout the interstices of the stratum corneum
Occlusive Moisturizers • hydrocarbon oils and waxes (petrolatum, mineral oil, paraffin, squalene), • silicone (cyclomethicone, dimethicone) • vegetable oils (castor oil, corn oil, grape seed oil, soybean oil), • animal oils (mink oil, emu oil), • fatty acids (lanolin acid, stearic acid), • fatty alcohol (lanolin alcohol, cetyl alcohol), • polyhydric alcohols (propylene glycol), • wax esters (lanolin, beeswax, stearyl stearate), • Vegetable waxes (carnauba wax, candelilla wax), • phospholipids (lecithin) • sterols (cholesterol, ceramides)
Humectants • Humectants are substances that attract moisture • Biologic humectants: hyaluronic acid and other glycosaminoglycans • Humectants can only hydrate the skin from the environment when the ambient humidity exceeds 70%. • Induce corneocyte swelling and minimizing voids between the desquamating corneocytes improve xerotic skin • Most moisturizers combine both occlusive and humectant moisturizing ingredients • They include glycerin, honey, sodium lactate, urea, propylene glycol, sorbitol, pyrrolidone carboxylic acid, gelatin, hyaluronic acid, and some vitamins and proteins
Moisturizer Remoisturizationof the skin must occur in four steps: ● initiation of barrier repair ● alteration of surface cutaneous moisture partition coefficient ● onset of dermal–epidermal moisture diffusion ● synthesis of intercellular lipids • aquaporin 3 channels in the skin had modulation by glycerin and urea (another mechanism for moisturization)
Astringents or toners • Either used to correct the deficiencies of the cleanser or supplement the effects of the moisturizer • They are used after cleansing but before moisturizing, and they are left on the face following use • Usually liquids wiped over the face with a cotton ball • Currently, astringents are used to remove the oily residue left behind after cleansing of the face with lipid-free cleansers or cleansing creams • A complete cosmetic facial treatment involves a cleanser followed by an astringent and then a moisturizer. Then , colored cosmetics are applied
Facial foundation • Basically pigmented moisturizers worn for 8 hours or longer before removal • Represent the colored facial cosmetic with the greatest impact on the integrity of the skin
4 basic facial foundation formulations • Oil-based: for dry skin, (water-in-oil) , easy to apply,, do not shift color as they mix with sebum, color is fully developed in the oily phase of the formulation, playtime : 5 min • Waterbased (oil-in-water emulsions) : for all skin types, also not subject to color drift, playtime : (amount of time the product can be moved over the Face) is shorter than with oilbased foundations. • Oil-free: for oily skin, non-comedogenic, non-acnegenic and hypoallergeniccontain no animal, vegetable or mineral oils. They contain other oily substances, such as dimethicone or cyclomethicone • Water-free or anhydrous forms (waterproof) : extremely long-wearing and used for camouflage or theatrical purposes
Facial foundation • Start with proper color match to the skin at the jawline and application with the fingertips • must be evenly applied to create the optimal cosmetic appearance and achieve the secondary benefit of sun protection. • A facial foundation without any added organic sunscreen ingredients has a sunburn protection factor (SPF) of at least 4 but at least 8 if used to camouflage underlying pigmentation • inclusion of additional sunscreen agents to the facial foundation can raise the SPF to 15 • facial foundation is an excellent, cosmetically elegant facial photoprotectant