Cyclopentasiloxane

Cyclopentasiloxane is a silicon-based (five silicon atoms) cyclic compound, a volatile cyclic dimethyl siloxane, D5 (Decamethylcyclopentasiloxane). It is a clear, colorless liquid with low viscosity, high volatility, and without odor. It is non-polar and insoluble in water but miscible with oils, alcohols, esters, and other solvents frequently used in decorative cosmetics and personal care applications.

Cyclopentasiloxane is soluble in isopropyl myristate, mineral oil, and ethanol. It is insoluble in propylene glycol and water. It provides a smooth, silky, lubricious feel upon application.

Cyclopentasiloxane evaporates from the skin without a cooling or burning effect due to its low heat of vaporization. Therefore, it is used as a delivery system in face creams, antiperspirants, deodorants, cuticle-coating preparations, and color-cosmetic compositions.

Cyclopentasiloxane is a potent diluent or carrier that evenly distributes actives and pigments on the skin surface. In addition, it provides enough "play-time" in decorative cosmetics, thereby improving rub-in properties, reducing stickiness, and imparting lubricity and a smooth skin feel. In skin care products, this cyclomethicone serves as a non-comedogenic emollient.

In hair-care products, Cyclopentasiloxane supports the easy spreading of high-viscosity fluids or gums, improves wet combability, and functions as a resin plasticizer in fixative products. In addition, in composition with dimethicone, it allows for controlling drying duration depending on product requirements.