Maltodextrin is a plant-based sugar that is used in cosmetics and personal care products as a moisturizer, absorbent, binding agent, emulsion stabilizer, and film-forming agent.
Maltodextrin is a polysaccharide, which means it is composed of long chains of monosaccharide (sugar) units bound together by glycosidic linkages. In nature, polysaccharides are ubiquitous, found extensively in both plants and animals.
Maltodextrin is prepared as a white powder or concentrated solution by partial hydrolysis of corn starch, potato starch, or rice starch with suitable acids and enzymes. The term “maltodextrin” can be applied to any starch hydrolysis product that contains fewer than 20 dextrose (glucose) units linked together. Maltodextrins are classified by DE (dextrose equivalent) and have a DE between 3 and 20. The higher the DE value, the higher the sweetness and solubility, and the lower heat resistance.
In addition to use in cosmetics, maltodextrin is commonly used for the production of soft drinks, candy, and a variety of other processed foods. Maltodextrin is easily digestible, being absorbed as rapidly as glucose. Maltodextrin is soluble and readily dispersible in water, however, it is only slightly soluble to almost insoluble in alcohol.
In cosmetics and personal care products, maltodextrin functions as a moisturizer, absorbent, binding agent, emulsion stabilizer, and film-forming agent. It may also be able to enhance the anti-aging benefits of hydroxy acids, which are commonly used in anti-aging products.
Maltodextrin functions as a moisturizing ingredient because it reflects the composition of Natural Moisturizing Factor (NMF) found within the skin’s epidermis. The NMF is an expansive group of substances including amino acids, PCA, lactates, sugars, salts, urea, and peptides. All of these substances work together to keep the skin’s surface intact, supple, and hydrated. As we age, the NMF can become depleted. Routine exposure to sensitizing ingredients like drying cleansing agents and denatured alcohol can also deplete the NMF. The result is visibly dry, tight-feeling, flaky skin. As a polysaccharide, maltodextrin mimics the sugars found in NMF, effectively drawing in moisture to maintain skin hydration.
Maltodextrin also functions as an absorbent and binding agent in cosmetic products. Since it is constructed with simple sugar building blocks that are easily hydrated in an aqueous environment, it has the ability to create a gel-like structure in formulations. As a binder, maltodextrin works to bind other ingredients together and prevent them from coming apart. For example, binders are often used in pressed powders to keep them together in the container.
As an emulsion stabilizer, maltodextrin is often used in products that contain both water and oil components. When water and oil are combined in a formulation, a dispersion of oil droplets in water – and vice versa – is formed. However, the two phases can separate if the emulsion is left to settle. To address this problem, an emulsion stabilizer like maltodextrin can be added to the system. This helps the droplets remain dispersed and produces a stable emulsion.
Maltodextrin has also be suggested to possess anti-aging and anti-irritation properties. In 2002, a patent filed by a company called Unilever presented research on the use of maltodextrin in combination with hydroxy acids. Hydroxy acids (i.e. alpha hydroxy acids and beta hydroxy acids) are commonly used in skin care products due to their ability to improve the appearance of photodamaged or naturally aged skin, skin lightening, treatment of age spots, etc. One problem with hydroxy acids, however, is that they can cause skin irritation such as redness and stinging. Researchers found that while maltodextrin itself was not an anti-aging compound, it enhanced the anti-aging activity of the acids and reduced skin irritation.
According to the United States Food and Drug Administration, maltodextrin is an approved direct food additive affirmed as generally recognized as safe (GRAS).
The Cosmetic Ingredient Review Expert Panel assessed the safety of plant polysaccharide gums, including maltodextrin, as used in cosmetics. The Panel noted that out of all the ingredients reviewed in the safety assessment, maltodextrin had the highest reported cosmetic ingredient use frequency. After evaluating the scientific data, the Panel found maltodextrin to be a mild ocular (eye) irritant. Maltodextrin was not a dermal irritant or sensitizer.
References: Wikipedia, “Maltodextrin”, Polysaccharides Bioactivity and Biotechnology, 2015, (pp.1867-1892), Truth In Aging, “Maltodextrin”, United States Patent 6440432, Cosmetic Ingredient Review, “Safety Assessment of Plant Polysaccharide Gums as Used in Cosmetics”, 2014.