![]() ![]() Most of them are represented by low molecular weight substances such as glycerol (probably the most commonly used humectant), urea, propylene glycol and pyrrolidone carboxylic acid, α-hydroxy acids (lactic, glycolic and tartaric acids) few high molecular weight substances such as hyaluronic acid, are also used in moisturizers. The humectants attract water from dermis to epidermis. ![]() Common occlusive substances in moisturizers are lipids (petrolatum, beeswax, lanolin and various oils). The occlusive ingredients physically block transepidermal water loss by forming a hydrophobic film on the skin surface and within the superficial interstitium between corneocytes. They must contain mainly occlusive, humectant and emollient ingredients. An important class of cosmetic products is represented by creams. The main raw materials used to obtain cosmetics are water, oily materials (oils, fats), humectants, antioxidants, preservatives, pharmaceutical agents, fragrances. The preservation of skin health and the skin disorders that affect the life quality of many patients have been the object of several studies on the preparation and characterization of a wide range of skin-care cosmetics and dermatocosmetic products. The obtained emulsions were found to present pseudoplastic and thixotropic behaviors, adequate for cosmetic skin care product formulations. The designed formulations were assessed by means of their physico-chemical properties (pH, viscosity, thixotropic behavior), optical microscopy analysis and sensorial characteristics. As preservatives, Cosgard (containing benzyl alcohol, salicylic acid, glycerol, ascorbic acid) and mixtures of two essential oils (lemon and lavender) were selected. As emulsifier, a plant based product containing glyceryl stearate and potassium stearate was incorporated (in the concentration range 4–5 %), while as rheology modifier xanthan gum was used (in the concentration range 0.2–1 %). As oil phases, mixtures of coconut, almond, jojoba, avocado oils (in different ratios) were used while the water phase consisted in lavender water. The present study was focused on the preparation and characterization of different topical oil in water emulsions based on natural ingredients such as collagen hydrolysate and vegetable oils mixtures. ![]()
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