NATURALS 59
Theoretical SPF UV filters
UVA
Butyl Methoxydibenzoylmethane Zinc Oxide
Benzophenone-3 Ethythexyl Salicylate Homosalate
UVB Ethylhexyl Methoxycinnamate
Titanium Dioxide (and) Alumina (and) Stearic Acid
Titanium Dioxide (and) Silica Total PolyAquolTM- -OS2 Viscosity (Brookfield, RVDV-I) Stability (1 month at 50ºC) 5%
13% 5%
28000cps
(Sp 93, 10rpm) Stable
21.26% 4%
18000cps
(Sp 92, 10rpm) Stable
Figure 9: Sunscreen formulations with PolyAquol-OS2. The polyglycerol-based emulsifier was used to generate sunscreen formulations in the presence of various organic and inorganic UV filters. Emulsions were made at 80°C (SPF 15) or at room temperature (cold-process) (SPF 25). Stability was visually assessed (phase homogeneity or separation) after 1 month at 50°C. Viscosity was measured with a Brookfield apparatus, RVDV-I Prime, Sp 92 or 93, as indicated, at 10 rpm.
air pockets at the surface of pigments agglomerates. We could propose an interaction of the polyglycerol head with the polar surface of pigments while the lipophilic tail would merge with the oil phase. This would in turn reduce the interfacial tension between pigment agglomerates and the surrounding oil phase. In other words, the polyglycerol-based emulsifier would ‘bridge’ pigment particles to the continuous oil phase facilitating their dispersion. Once dispersed, pigment particles may tend to re-agglomerate through a process known as flocculation. This also involves van der Waals attractive forces between pigment particles.10
The polyglycerol-based
emulsifier could play a second role as a dispersing agent reducing attractive forces between pigment particles thereby preventing flocculation and controlling particle size. Earlier in this article we proposed a mechanism of steric stabilisation to prevent water droplet coalescence (Fig 5). The oligomeric configuration of the polyglycerol-based emulsifier could also apply with pigments by acting as a barrier preventing their re-agglomeration. The wetting/dispersing properties of the polyglycerol-based emulsifier thus directly apply to the formulation of colour cosmetics such as BB, CC creams, foundations and anhydrous lip sticks or balms. Adequate pigment dispersion is required for a uniform spreading and skin coverage. While pigment dispersion directly affects the performance and
June 2018
sensorial properties of colour cosmetics it also applies to sunscreen formulations especially when physical UV filters are used. Here again, a homogeneous distribution of the filters will ensure satisfactory formulation aesthetics and an adequate UV protection. The polyglycerol-based emulsifier demonstrated a high level of compatibility with inorganic as well as with organic UV filters. Formulations with theoretical values of SPF 15 (only inorganic filters) and SPF 25 (inorganic and organic filters; cold-processed) were shown to be fully stable after one month at 50°C (Fig 9). Values of SPF 50 could be also reached using the polyglycerol-based emulsifier by combining inorganic and organic filters.
Conclusion The polyglycerol-based emulsifier described in this article will help rediscovering W/O systems and also opens doors to various cosmetic applications. The patent pending technology behind PolyAquol-OS2 allowed for the formation of an oligomeric configuration that brings numerous properties in formulations. High levels of stability, robustness, unique sensoriality, multifunctionality and global regulatory acceptance are all attributes displayed by PolyAquol-OS2. We have demonstrated the benefits of our emulsifier for makeup and sunscreen formulations. It can be used in completely anhydrous systems (lip sticks) and can also become a carrier for
15 Inorganic 8%
25 (Cold-process) Organic & inorganic
4% 5% 7% 5.26%
small amounts of water in lip balms for instance. The all-natural and palm-free origins paired with an excellent safety profile make PolyAquol-OS2 an outstanding candidate also for baby care products. Indeed, we have produced a diaper rash cream made with 15% ZnO showing the stability and sensorial properties typically obtained with PolyAquol-OS2. In addition to more specialised applications, PolyAquol™-OS2, because if its characteristics notably the sensoriality it confers to emulsions, is ideal for all skin care formulations. All those features position it as an ideal W/O self-emulsifier for countless cosmetic applications. The availability of PolyAquol-OS2 to all chemists and cosmetologists is likely to open new frontiers in designing multi-functional and efficacious formulations.
PC
References 1 Kizling J, Kronberg B. On the formation of concentrated stable w/o emulsions. Adv Colloid Interface Sci. 2001, 89-90:395-9.
2 Aronson MP, Petko F. Highly Concentrated Water- in-Oil Emulsions: Influence of Electrolyte on Their Properties and Stability. Journal of Colloid and Interface Science 1993; 159: 134-149
3 Israelachvili JN. Intermolecular and Surface Forces, Third edition 2011. Academic Press, 704 pp.
4 An N, Zhuang B, Li M, Lu Y, Wang ZG. Combined Theoretical and Experimental Study of Refractive Indices of Water−Acetonitrile−Salt Systems. J Phys Chem B. 2015; 119:10701-9
5 Park CI, Cho WG, Lee SJ. Emulsion stability of cosmetic creams based on water-in-oil high internal phase emulsions. Korea-Australia Rheology Journal 2003; 15: 125-130
6 Márquez AL, Medrano A, Panizzolo LA, Wagner JR. Effect of calcium salts and surfactant concentration on the stability of water-in-oil (w/o) emulsions prepared with polyglycerol polyricinoleate. Journal of Colloid and Interface Science 2010; 341: 101–108
7 Nikolovski BG, Ilić JD, Sovilj MN. How to formulate a stable and monodisperse water-in- oil nanoemulsion containing pumpkin seed oil: the use of multiobjective optimization. Braz. J. Chem. Eng. 2016; 33: 919-931.
8 Lazaridis N, Alexopoulos AH, Chatzi EG and Kiparissides C. Steric stabilization in emulsion polymerization using oligomeric nonionic surfactants. Chemical Engineering Science 1999; 54: 3251-3261
9 Ushikubo FY, Cunha RL. Stability mechanisms of liquid water-in-oil emulsions. Food Hydrocolloids 2014; 34: 145-153
10 Tadros T. General Principles of Colloid Stability and the Role of Surface Forces. Colloids and Interface Science Series, Vol. 1 Colloid Stability: The Role of Surface Forces, Part I. Edited by Tharwat F. Tadros Copyright ©
2007 WILEY-VCH
Verlag GmbH & Co. KGaA, Weinheim Pages 1-22
PERSONAL CARE EUROPE
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88
