Chemical Properties
Cyclomethicone occurs as a clear, colorless and tasteless volatile liquid.
Uses
Pharmaceutic aid (wetting agent).
Production Methods
Cyclomethicone is manufactured by the distillation of crude polydimethylsiloxanes.
Brand name
VS-7158
(Witco); VS-7207 (Witco); VS-7349 (Witco).
Pharmaceutical Applications
Cyclomethicone is mainly used in topical pharmaceutical and cosmetic formulations such as water-in-oil creams.
Cyclomethicone has been used in cosmetic formulations, at concentrations of 0.1-50%, since the late 1970s and is now the most widely used silicone in the cosmetics industry. Its high volatility, and mild solvent properties, make it ideal for use in topical formulations because its low heat of vaporization means that when applied to skin it has a ‘dry’ feel.
Safety
Cyclomethicone is generally regarded as a relatively nontoxic and nonirritant material. Although it has been used in oral pharmaceutical applications, cyclomethicone is mainly used in topical pharmaceutical formulations. It is also widely used in cosmetics. Studies of the animal and human toxicology of cyclomethicone suggest that it is nonirritant and not absorbed through the skin. Only small amounts are absorbed orally; an acute oral dose in rats produced no deaths.
storage
Cyclomethicone should be stored in an airtight container in a cool, dry, place.
Toxics Screening Level
The initial threshold screening level (ITSL) for cyclopolydimethylsiloxane 30 μg/m3 based on an annual averaging time.
Regulatory Status
Included in the FDA Inactive Ingredients Database(oral powderfor reconstitution, topical lotion, topical cream, topical emulsion). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
