Very few skincare products excite consumers or provide the immediately noticeable skin appearance benefits of instant skin tighteners. Within minutes they can dramatically improve the appearance of bags under the eyes and facial wrinkles. The effect is most noticeable around the crow’s feet area and under-eye bags since the skin is thinner and more responsive to tightening ingredients. These products work best on women whose faces show little emotion or movement, which helps prevent the film from cracking and turning white on skin.
Skin tightening products are not new but were first commercialized by Laboratoires Sérofart in the 1930s by Dr. Jacques C. Risler. The product, Serofart, used albumin extracted from horse serum blood as an active to tighten skin. The product was, however, discontinued in 1939 due to difficulties preserving the product. In the 50s and 60s, numerous other serum albumen-based products were introduced, such as Helena Rubinstein Skin Serum, Helene Curtis Magic Secret, Coty’s Line Away, Hazel Bishop’s Sudden Change, Studio Girl’s Soft-Focus Temporary Wrinkle Remover, Max Factor’s Touch of Youth Wrinkle Smoothing Lotion, Lilly Daché’s Instant Change, and Revlon Wonderlift Wrinkle Remover. All of these wrinkle smoothers were based on bovine serum albumin, a protein extracted from the blood of cattle (1). In the 70s and 80s, new types of instant skin tighteners emerged based on using 2-6% sodium silicate or sodium metasilicate as an active. These products all had a high pH of ~11, which can cause skin irritation and whitening due to the brittle nature of the film. However, the skin has a high buffering capacity which can rapidly normalize skin pH, which may help reduce some of the irritation potential. Soap bars, for example, have a pH of 9-10 and are not very irritating in the absence of hard water. Widely used sodium stearate-based deodorants are leave-on products applied to sensitive, shaved underarm skin, and they are well tolerated in spite of having a pH of ~9. Modern sodium silicate-based tighteners use polyols to help plasticize the film and clays to help provide a matt soft-focus effect to the film. Additional film formers are also used in some formulations.
Types of skin tightening formulations
- Sodium silicate based formulations
- The main film-forming ingredient is sodium silicate (also known as sodium metasilicate, water glass). Typical use levels are 5 to 10% of a 37.5% active solution.
- Polyols like glycerin, propylene glycol, and butylene glycol help plasticize the film on skin, making it less brittle. Typical use levels are 5-8%.
- Clays used include bentonite, magnesium aluminum silicate, lithium magnesium sodium silicate and sodium magnesium fluorosilicate. The clays provide thickening and help provide a matt, soft-focus appearance. They also speed the drying time of the film on skin and reduce the initial watery skin feel. The typical use levels are .5-2%.
- Soft focus powders such as spherical silica, cellulose, polymethylsilsesquioxane, and dimethicone/vinyl dimethicone crosspolymer.
- Hybrid formulations using sodium silicate and natural or synthetic polymers. Soft focus powders can also be added for additional wrinkle blurring effects.
- Polymers used include pullulan, xanthan gum, and sodium polystyrene sulfonate.
- Natural or synthetic polymer-based formulations
- Skin tighteners can be made using only natural or synthetic water-soluble polymeric solutions that form films that contract when applied to skin. The films also reduce lines and wrinkles due to their hydration effects on skin that can help to visually reduce the appearance of wrinkles. These products are not as effective as sodium silicate-based products but are less irritating and whitening.
- Typical natural-based polymers used include pullulan, egg albumin, gliadin, acacia senegal gum, rhizobian gum, hydrolyzed wheat protein/pvp, hydrolyzed chenepodium quinoa seed, hydrolyzed sesame protein pg, and porphyridium polysaccharide-frutarom. Use levels range from 1-3%.
- Synthetic polymers used include sodium polystyrene sulfonate, polyacrylate 21, adipic acid/neopentyl glycol crosspolymer, hdi/trimethylol hexyllactone cross polymer.
- Soft focus powders can also be added for additional wrinkle blurring effects: Dimethylacrylamide/acrylic acid/polystyrene ethyl methacrylate copolymer and polyurethane-2, polymethyl methacrylate.
- Can also include humectants as film plasticizers and to increase hydration. The moisturizing effects may be caused by plumping caused by the keratinocyte absorption of water via aquaporin channels. Good moisturizers have been shown to reduce the appearance of fine lines and wrinkles by up to 30%.
- Two-part formulations are activated when combined. These typically include a prepolymer and an activating catalyst that promotes polymer cross-linking or polymerization.
- Neotensil contains Strateris™, a two-step topical formulation technology which claims no irritation or usage problems. The Contouring Complex (Step 1) is a proprietary dispersion of polydimethylsiloxane polymers in an aqueous medium. The Activator (Step 2) is a water-in-silicone emulsion that is applied over the Contouring Complex to immediately improve the appearance of facial skin. The effect is claimed to last all day until Strateris is removed. Neotensil won the Allure Best of Beauty Breakthrough 2014 award. The product has the best performance of any skin tightening product I have evaluated. Note: the product was discontinued in 2015.
- I like this approach and believe it represents the best formulation strategy when combined with soft-focus technology.
Key formulation challenges
- Balancing performance and irritation potential with good product skin appearance, feel, and comfort is critical. Key performance parameters include film durability over time, cracking, flaking, whitening, peeling, and minimizing skin shine.
- Flexibility of the technology. Can it be used with a moisturizer or foundation?
- Ease of use, easy uniform product application. This suggests that packaging or a novel delivery device may be critical.
References
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