Hectorite, a natural clay: from formulation and in vitro tests to in vivo oil and sweat control efficient cosmetic products.
267
Presented by: Olga Biganska
Modern consumers expect from cosmetics ever more benefits such as naturalness and new sensorial experience whitout any trade-off in performance. Cosmetics dedicated to oily skin should ensure long lasting oil and sweat control while long lasting wetness and odor protection are expected from deodorants.
Hectorite is a specific natural clay of smectite-type, with a strong exfoliation ability that, in aqueous media, leads to the formation of gels which present some interesting features for cosmetic products. Indeed, after application of hectorite gels onto the skin, the dry films have the ability to absorb sebum; they show long lasting mattifying efficacy in in vitro and in vivo instrumental tests. However, formulating hectorite, especially in presence of some particular ingredients (such as salts), remains a highly challenging task. This is the case for magnesium containing compounds (ex. MgO, Mg(OH)2) known for their anti-bacterial and anti-odor efficacy.
To overcome the formulation challenge and provide stable, safe and efficient cosmetic products we needed to understand both the interactions between hectorite and magnesium salts and the influence of other raw materials commonly used in cosmetics.
Then, different formulae, either for oily skin care or for deodorant, based on hectorite/MgO association were designed with the aim to demonstrate their efficacy.
For this purpose, the anti-shine efficacy was evaluated after application of the formulations on faces of 28 women with oily/mixed skin placed and exposed to hammam conditions. The formulation containing 3% of hectorite + 0.9% of MgO significantly limited the skin shine in comparison to bare skin and the reference.
Hence, a clinical study was conducted for 3 months on 234 subjects with oily skin presenting both inflammatory and non-inflammatory lesions. The formulation containing 3% of hectorite + 0.9% of MgO showed statistically significant and strong clinical efficacy on non-inflammatory acne lesions vs placebo.
Furthermore, in order to also validate the consumer perception of 3% of hectorite + 0.9% of MgO formula efficacy, the product was used by 30 mowen with mixed or oily skin during 7 days. Users noticed the long-lasting matte finish and the blurring effect of the formula. They appreciated the oil control provided by the product as well as its lasting; they found their pores to be less visible, making for an even complexion which lasts throughout the day. Over time, they noticed that the formula also tackles other deeper skin imperfections such as blemishes, spots, pores, and skin redness on top of superficial shine and oiliness.
The first step to evaluate the deodorant efficacy consisted of performing Olfactive Sensory Experts tests. The objective was to compare formulation containing 5% of hectorite + 2% of MgO versus non treated armpit and versus market deodorant reference. We observed a significant decrease of odor intensity: -18% (at 24h) and -16% (at 48h) versus the non treated armpit. Moreover, the deodorant efficacy after 24h was similar to the efficacy of one of the leading commercial products.
The second step was to confirm and validate consumer perception, using a home routine for 2 weeks, with 140 users of contact deodorants (stick / roll-on), with a 100% “eco-friendly / eco-aware” profile. Two proposals of formulation (5% of hectorite + 2% of MgO in jar and 3% of hectorite + 2% of MgO in tube) were tested in comparison to a market deodorant reference. Overall, the users were generally satisfied and liked the performance of tested products, especially on deodorant and anti-perspirant efficacy as well as long lastingness. The anti- odor efficacy was superior with 3% of hectorite + 2% of MgO formula in tube product and at parity with 5% of hectorite + 2% of MgO formula in jar versus market reference.
Moreover, the consumers observed with both hectorite/MgO products higher care benefits when compared to market reference: soothing, softness, no irritation, gentleness. However, the consumers needed to adapt or modify their gesture / routine to optimize the performance of this technology.
Thanks to formulation understanding in vivo efficacy of formulations based on hectorite/MgO association has been evidenced through different tests vs market products. Efficacy was also perceived by consumers when comparing tested product versus market references, highlighting that the hectorite/MgO association has high potential for cosmetic applications.
Hectorite is a specific natural clay of smectite-type, with a strong exfoliation ability that, in aqueous media, leads to the formation of gels which present some interesting features for cosmetic products. Indeed, after application of hectorite gels onto the skin, the dry films have the ability to absorb sebum; they show long lasting mattifying efficacy in in vitro and in vivo instrumental tests. However, formulating hectorite, especially in presence of some particular ingredients (such as salts), remains a highly challenging task. This is the case for magnesium containing compounds (ex. MgO, Mg(OH)2) known for their anti-bacterial and anti-odor efficacy.
To overcome the formulation challenge and provide stable, safe and efficient cosmetic products we needed to understand both the interactions between hectorite and magnesium salts and the influence of other raw materials commonly used in cosmetics.
Then, different formulae, either for oily skin care or for deodorant, based on hectorite/MgO association were designed with the aim to demonstrate their efficacy.
For this purpose, the anti-shine efficacy was evaluated after application of the formulations on faces of 28 women with oily/mixed skin placed and exposed to hammam conditions. The formulation containing 3% of hectorite + 0.9% of MgO significantly limited the skin shine in comparison to bare skin and the reference.
Hence, a clinical study was conducted for 3 months on 234 subjects with oily skin presenting both inflammatory and non-inflammatory lesions. The formulation containing 3% of hectorite + 0.9% of MgO showed statistically significant and strong clinical efficacy on non-inflammatory acne lesions vs placebo.
Furthermore, in order to also validate the consumer perception of 3% of hectorite + 0.9% of MgO formula efficacy, the product was used by 30 mowen with mixed or oily skin during 7 days. Users noticed the long-lasting matte finish and the blurring effect of the formula. They appreciated the oil control provided by the product as well as its lasting; they found their pores to be less visible, making for an even complexion which lasts throughout the day. Over time, they noticed that the formula also tackles other deeper skin imperfections such as blemishes, spots, pores, and skin redness on top of superficial shine and oiliness.
The first step to evaluate the deodorant efficacy consisted of performing Olfactive Sensory Experts tests. The objective was to compare formulation containing 5% of hectorite + 2% of MgO versus non treated armpit and versus market deodorant reference. We observed a significant decrease of odor intensity: -18% (at 24h) and -16% (at 48h) versus the non treated armpit. Moreover, the deodorant efficacy after 24h was similar to the efficacy of one of the leading commercial products.
The second step was to confirm and validate consumer perception, using a home routine for 2 weeks, with 140 users of contact deodorants (stick / roll-on), with a 100% “eco-friendly / eco-aware” profile. Two proposals of formulation (5% of hectorite + 2% of MgO in jar and 3% of hectorite + 2% of MgO in tube) were tested in comparison to a market deodorant reference. Overall, the users were generally satisfied and liked the performance of tested products, especially on deodorant and anti-perspirant efficacy as well as long lastingness. The anti- odor efficacy was superior with 3% of hectorite + 2% of MgO formula in tube product and at parity with 5% of hectorite + 2% of MgO formula in jar versus market reference.
Moreover, the consumers observed with both hectorite/MgO products higher care benefits when compared to market reference: soothing, softness, no irritation, gentleness. However, the consumers needed to adapt or modify their gesture / routine to optimize the performance of this technology.
Thanks to formulation understanding in vivo efficacy of formulations based on hectorite/MgO association has been evidenced through different tests vs market products. Efficacy was also perceived by consumers when comparing tested product versus market references, highlighting that the hectorite/MgO association has high potential for cosmetic applications.