Perfumes microemulsions

Understanding surfactant phase behavior is important because it controls physical properties such as rheology and freeze-thaw stability of formulations. It is also closely related to the ability to form and stabilize emulsions and microemulsions. Micelles, vesicles, mi-croemulsions and liquid crystal phases have all been used as delivery vehicles for perfumes or other active ingredients. 

Figure 8.6 Pseudoternary phase diagram of a system containing 20 wt.% emulsifier (Cs/io-APG, Q2/14-APG and GMO), 20 wt.% perfume oil, 0.6 wt.% oil (dicapryl ether, octyldodecanol) and 59.4 wt.% water at 25°C. The formation of microemulsions was studied as a function of the emulsifier s composition. The dotted lines separate the o/w- from the w/o-region. ME indicates a one-phase microemulsion. (From Ref. [39], reprinted with permission of Elsevier.)...

The transfer of well-known perfume brands into cosmetic formulations will lead to the challenge of maintaining the perfume impression despite possible interactions with cosmetic care compounds. Microemulsions have proven to be very efficient in this respect. For example, a clear aftershave microemulsion formulated with non-ionic surfactants and isoeicosane is almost non-interfering with the perfume impression [45]. Because of the trend to reduce the amount of volatile organic chemicals, ethanol-free perfume micro emulsions are under further development. Non-sticky, non-fatty and ethanol-free products can be obtained through the usage of vicinal diols such as 1,2-hexanediol in microemulsion formulations [46]. 

Chung, S.L., Tan, C.-T., Tuhill, I.M., and Scharpf, L.G. 1994. Transparent oil-in-water microemulsion flavor or fragrance concentrate, process for preparing same, mouthwash or perfume composition containing said transparent microemulsion concentrate, and process for preparing same. U.S. Patent 5283056, filed July 1, 1993, and issued Feb. 1, 1994. 

A microemulsion of low water content has been found to be an excellent medium for synthesis of long-chain lactones [97]. These compounds, which are important perfume ingredients, are not easily made by conventional organic synthesis because intermolecular esterification dominates over intramolecular esterification. In the microemulsion, the molecular arrangement at the oil/water interface seems to favor the cyclization reaction (Fig. 15). 

Stearyl trimethylammonium chloride, PEG, and perfume are added to a solution of water and microemulsion polystyrene latex with stirring. 

Uses Emollient, solubilizer, refatting agent, emulsifier for cosmetics, perfumes, essential oils solubilizer for essential oils and triglycerides skin conditioner for body washes, liq. hand soaps coemulsifier in creams/lotions, microemulsions Trade Name Synonyms Lexol EO [Inolex http //www.inolex.com], Oxypon 288 [Zschimmer Schwarz http //www.zschimmer-schwarz.de], Sympatens-TOL/100 [Dr. W. Kolb, AG http //www.kolb.ch]... 

Due to their transparency, microemulsions represent a very attractive type of cosmetic formulation, e.g. hair styling gels, perfume gels, bath preparations, sunscreen gels, etc. Their main problem is the relatively high surfactant concentration required for their formulation compared with nano- and macroemulsions. Proper choice of the surfactant system used for their formulation is required to avoid any side-effects, e.g. skin irritation. To arrive at the optimum composition of microemulsion systems, one needs to the phase diagram for these multicomponent formulations. 

Another potential field of application for microemulsions in the cosmetics sector is low-VOC (volatile organic carbon) perfumes. Traditionally, toilet waters, shaving lotions, etc., are alcoholic solutions of certain perfume oil mixtures. Alkyl polyglycoside microemulsions can now be used as a basis for creating nonalcoholic toilet waters with new property profiles." ... 

Uses Emulsion stabilizer, emulsifier, moisturizer, and emollient for creams and lotions plasticizer perfume solubilizer for microemulsions in clear gel formulations... 

A model formulation was selected consisting of 20% emulsifier mixture (alkyl polyglycoside and GMO), 20% perfume oil, less than 2% oil (dicapryl ether and octyldodecanol), and water. The GMO was chosen as coemulsifier because it proved to be most suitable for nonpolar oil. No microemulsion is formed if C,2/i4 alkyl polyglycoside and GMO are used as emulsifiers for this system. It was reported that the oil solubility of the surfactant in systems... 

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