BRIDGING THE GAP BETWEEN LONG LASTING AND ACTIVE INGREDIENTS DELIVERY IN COLOR COSMETICS: AN IN-DEPTH STUDY USING IN VITRO AND IN VIVO PERMEATION TECHNIQUES
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Presented by: Milene Haraguchi Padilha
BACKGROUND
The interest for multipurpose makeup has grown in the last few years, as the world is evolving at a faster pace and pushing beauty trends at the same speed. Consumers are looking for multi-functional formulations and color cosmetics that go beyond decoration.
Silicone-based film formers are key ingredients to achieve long lasting in color cosmetics, however, what will be its impact on the delivery of skin care actives when these are added to multi-functional color cosmetics? Little is known about it.
OBJECTIVE
This work aims to address this puzzling question by determining the influence of silicone-based film formers on the delivery and long-lasting properties of a variety of skin care actives added to color cosmetic formulations.
MATERIALS AND METHODS
The following silicone-based film formers were under investigation: Trimethylsiloxysilicate, Dimethiconol/Trimethylsiloxysilicate Crosspolymer, Polypropylsilsesquioxane and Acrylates/Polytrimethylsiloxymethacrylate Copolymer. Niacinamide (nicotinamide) was elected as the active ingredient of reference for method validation and discussion of results.
Cosmetic formulations are complex systems due to the presence of numerous chemical ingredients, making it difficult to isolate and investigate individual contributions. To mitigate that, three main variables were selected and isolated in steps: phase, film formers and pigments. The active of interest was kept constant in all experiments.
The permeation of niacinamide from either an aqueous solution or non-pigmented/pigmented water-in-silicone emulsions (W/Si) were determined by in vivo and in vitro measurements. The ATR-FTIR technique was used to evaluate the permeation of niacinamide through Vitro-Skin, a collagen synthetic membrane that claims to mimic the surface properties of human skin. Infrared spectras were acquired at specific time intervals and wavelengths to quantify the concentration of niacinamide that reaches contact with the ATR crystal. In a second set of experiments, the Strat-M membrane, a synthetic model that is predictive of transdermal diffusion in human skin, was selected to study the permeation of niacinamide from water-in-silicone foundations and lipsticks using the well-known Franz diffusion cells technique. Finally, in vivo experiments were conducted to quantify the permeation of niacinamide through human stratum corneum using the tape-stripping technique. For both the Franz diffusion cells experiments and in vivo measurements, niacinamide permeation was quantified using UHPLC. Scanning electron microscopy was used to evaluate the effects of film-forming technologies on the morphology of water-in-silicone foundations and lipsticks thin films.
To study the effect of the film-forming technologies on the long-lasting properties of niacinamide, water-in-silicone emulsions were applied on a polydimethylsiloxane membrane and submitted to 25 rub-off cycles against a felt band to physically insult the film. The remaining active content was then extracted from the film and quantified by HPLC to determine the amount of active lost by abrasion.
RESULTS AND DISCUSSION
FTIR and tape stripping data revealed that niacinamide is delivered faster from an aqueous solution compared to a water-in-silicone emulsion. When silicone-based film formers are added to the later, niacinamide appeared to be distributed more homogeneously in the stratum corneum and the concentration of niacinamide recovered from the top layer of the epidermis is reduced. Taking into account the all over recovery analysis, it was found that the incorporation of silicone-based film formers into the water-in-silicone emulsion led to a more effective delivery of niacinamide. Tape stripping data showed that Dimethiconol/Trimethylsiloxysilicate Crosspolymer acts as a booster, delivering niacinamide even faster compared to the aqueous solution. Such a boosting effect could not be observed when using the Strat-M membrane, possibly due to inherent limitations of this synthetic membrane. Rub-off experiments confirmed the ability of silicone-based film formers to hold niacinamide on the skin surface, maximizing the benefits of the active ingredient when delivered from color cosmetic formulations.
CONCLUSION
This work demonstrated that silicone-based film formers improve the delivery of niacinamide from water-in-silicone emulsions and prevent its loss from abrasion. Morphology of the films were also significantly improved. It is believed that this study opens up a new frontier for makeup with valuable knowledge for the development of color cosmetics with skincare benefits. New insights for the development of sunscreen formulations with physical filters and skincare attributes can also be correlated.
The interest for multipurpose makeup has grown in the last few years, as the world is evolving at a faster pace and pushing beauty trends at the same speed. Consumers are looking for multi-functional formulations and color cosmetics that go beyond decoration.
Silicone-based film formers are key ingredients to achieve long lasting in color cosmetics, however, what will be its impact on the delivery of skin care actives when these are added to multi-functional color cosmetics? Little is known about it.
OBJECTIVE
This work aims to address this puzzling question by determining the influence of silicone-based film formers on the delivery and long-lasting properties of a variety of skin care actives added to color cosmetic formulations.
MATERIALS AND METHODS
The following silicone-based film formers were under investigation: Trimethylsiloxysilicate, Dimethiconol/Trimethylsiloxysilicate Crosspolymer, Polypropylsilsesquioxane and Acrylates/Polytrimethylsiloxymethacrylate Copolymer. Niacinamide (nicotinamide) was elected as the active ingredient of reference for method validation and discussion of results.
Cosmetic formulations are complex systems due to the presence of numerous chemical ingredients, making it difficult to isolate and investigate individual contributions. To mitigate that, three main variables were selected and isolated in steps: phase, film formers and pigments. The active of interest was kept constant in all experiments.
The permeation of niacinamide from either an aqueous solution or non-pigmented/pigmented water-in-silicone emulsions (W/Si) were determined by in vivo and in vitro measurements. The ATR-FTIR technique was used to evaluate the permeation of niacinamide through Vitro-Skin, a collagen synthetic membrane that claims to mimic the surface properties of human skin. Infrared spectras were acquired at specific time intervals and wavelengths to quantify the concentration of niacinamide that reaches contact with the ATR crystal. In a second set of experiments, the Strat-M membrane, a synthetic model that is predictive of transdermal diffusion in human skin, was selected to study the permeation of niacinamide from water-in-silicone foundations and lipsticks using the well-known Franz diffusion cells technique. Finally, in vivo experiments were conducted to quantify the permeation of niacinamide through human stratum corneum using the tape-stripping technique. For both the Franz diffusion cells experiments and in vivo measurements, niacinamide permeation was quantified using UHPLC. Scanning electron microscopy was used to evaluate the effects of film-forming technologies on the morphology of water-in-silicone foundations and lipsticks thin films.
To study the effect of the film-forming technologies on the long-lasting properties of niacinamide, water-in-silicone emulsions were applied on a polydimethylsiloxane membrane and submitted to 25 rub-off cycles against a felt band to physically insult the film. The remaining active content was then extracted from the film and quantified by HPLC to determine the amount of active lost by abrasion.
RESULTS AND DISCUSSION
FTIR and tape stripping data revealed that niacinamide is delivered faster from an aqueous solution compared to a water-in-silicone emulsion. When silicone-based film formers are added to the later, niacinamide appeared to be distributed more homogeneously in the stratum corneum and the concentration of niacinamide recovered from the top layer of the epidermis is reduced. Taking into account the all over recovery analysis, it was found that the incorporation of silicone-based film formers into the water-in-silicone emulsion led to a more effective delivery of niacinamide. Tape stripping data showed that Dimethiconol/Trimethylsiloxysilicate Crosspolymer acts as a booster, delivering niacinamide even faster compared to the aqueous solution. Such a boosting effect could not be observed when using the Strat-M membrane, possibly due to inherent limitations of this synthetic membrane. Rub-off experiments confirmed the ability of silicone-based film formers to hold niacinamide on the skin surface, maximizing the benefits of the active ingredient when delivered from color cosmetic formulations.
CONCLUSION
This work demonstrated that silicone-based film formers improve the delivery of niacinamide from water-in-silicone emulsions and prevent its loss from abrasion. Morphology of the films were also significantly improved. It is believed that this study opens up a new frontier for makeup with valuable knowledge for the development of color cosmetics with skincare benefits. New insights for the development of sunscreen formulations with physical filters and skincare attributes can also be correlated.