Stable O/W Nanoemulsions for Skin and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: February 26, 2010, from the March 2010 issue of Cosmetics & Toiletries.

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Lipids for pollen allergy protection: Beiersdorf AG has patented the use of lipid components in pharmaceutical and topical cosmetic formulations to protect against pollen allergies.¹⁵ A disclosed preparation comprised a lipid phase where one or more lipids had a viscosity of approximately 40–25,000 mPas. An example is shown in Formula 9.

Flexible, porous, dissolvable product form: The Procter & Gamble Company has disclosed personal care compositions in flexible, porous and dissolvable solid structures.¹⁶ The disclosed compositions comprise 23–75% surfactant, 10–50% water-soluble polymer and an optional 1.0–15.0% plasticizer. The company also has described a process for preparing the compositions. An example of a dissolvable, porous, solid cleanser is shown in Formula 10. It is prepared by mixing and heating the ingredients, vigorously aerating the mixture, spreading the mixture into molds, and drying the mixture.

Moisturizing composition for surgical gloves: Evonik Goldschmidt GmbH has disclosed a moisturizing liquid liner composition for a barrier layer such as surgical gloves.¹⁷ The moisturizing liner contains a hydrophobic moiety and an emulsifier. Nitrile gloves treated with a formulation of: 4.0% polyglyceryl-4 isostearate (and) cetyl PEG/PPG-10/1 dimethicone (and) hexyl laurate^f, 46.0% cyclomethicone, 47% cetyl dimethicone^g, 1.0% quaternium-80^h, and 2.0% dimethicone (350 cst) provided an increase in hand moisturization, compared with untreated gloves.

Stable o/w nanoemulsions for skin: Shiseido Co., Ltd. has disclosed the composition and manufacture of o/w nanoemulsions containing polyalkylene glycol dineopentanoates with excellent stability and skin application properties.¹⁸ The nanoemulsions, with 30–1,000 nm particle sizes, are suggested for lotions, creams and hair conditioners and are manufactured by preparing o/w microemulsion compositions with: nonionic surfactants having a hydrophilic-lipophilic balance (HLB) ≤ 5, polyalkylene glycol dineopentanoates, a water content ≤ 70% w/w, nonionic surfactants with a HLB ≥ 9, and polyoxyethylene-polyoxyalkylene random copolymer dialkyl ethers and/or polyhydric alcohol-polyoxyalkylene glycol-polyethylene glycol copolymer alkyl ethers and adding them to aqueous media containing potassium 4-methoxysalicylate.

The polyoxyethylene-polyoxyalkylene random copolymer dialkyl ethers were structured as: