DDS Liposomes for Cosmetic Delivery and Other Recent Literature Findings

By: Charles Fox, Independent Consultant

Posted: June 30, 2009, from the July 2009 issue of Cosmetics & Toiletries.

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Surfactant-coated, methacrylic polymer: Kao Corp. disclosed surfactant-coated, crosslinked, methacrylic polymer particles for cosmetics, and the production of these polymer particles.¹⁶ These particles impart smoothness and good dispersibility in a hydrophobic medium. In this medium a crosslinked, methacrylic acid ester-based polymer particle is prepared from a methacrylate ester and a carboxyl group-containing compound. In addition, the polymer particle is coated with a surfactant represented by a general formula:

R1CON(R2)R3

in which R1 is C7-22 monovalent hydrocarbon, and R2, R3 is either a hydrogen atom or any hydroxylalkyl group containing two or three carbon atoms. The polymer particle may be further coated with a sulfonate group-containing surfactant. A method for production of the polymer particle is also disclosed. For example, a polymer particle dispersion was prepared from lauryl methacrylate, ethylene glycol dimethacrylate, methacrylic acid, lauroyl peroxide, and N-stearoyl-N-methyl taurine sodium salt; and treated with palm kernel oil fatty acid diethanolamide to result in the present invention.

DDS liposomes for cosmetics: Miyajima et al. have published research on the application of drug delivery systems technology in liposomes for cosmetic materials.¹⁷ The cosmetic effect of acetyl hydroxyproline (AHYP) internally enveloped in liposomes was examined with the aim of enhancing the quality of cosmetic products. Also examined was the method for analyzing the enveloped AHYP in order to give credibility to cosmetic products.

The preparation of the liposomes AHYP, hydrogenated lecithin and cholesterol, and/or other cosmetic additives was dissolved by heating the preparation in dipropylene glycol. The solution was dispersed in a buffer solution, was particle-sized through an extruder, and was used as a cosmetic preparation. AHYP and cholesterol were quantified by using a high-performance liquid chromatography (HPLC) method; and the method for extracting AHYP from the liposomes also was examined to establish the method. After non-enveloped AHYP had been removed by using a dialysis tube, the enveloped AHYP was determined. The forearm flexor surface parts of monitors were washed and, after drying, the cosmetic preparation was painted on the parts. The moisturizing effect of the cosmic preparations was periodically measured on the keratinous water content at the painted partsb and on the evaporation of moisturec.