How to formulate with naturality and less or no water?

The market for anhydrous galenicals continues to develop, with a rise in the number of launches of this type of galenical since 2018. Oils and balms are the main products to be gaining in popularity. Oily galenics contain no water, but a combination of one or more vegetable and/or mineral oils. Balms, on the other hand, are a mixture of solid and/or liquid fats, the proportion of which influences the final texture of the balm, which can be more or less thick and solid. These formats appeal as much for their texture as for their sensoriality. 

In terms of formulas containing less water, known as concentrates, powders are all the rage, with two co-existing formats: anhydrous powders, which can be applied directly to the body, and powders requiring dilution to be applied. In both cases, this type of galenic is interesting for reducing water consumption. Dilutable powders, although initially anhydrous, require the addition of water at the time of final use at home, thus limiting its transport and reducing the water impact of the formula. This article will deal mainly with dilutable powders, appreciated for their ease of dilution when water is added to the chassis. However, solid formats are gradually gaining in popularity. They are appreciated for their practicality and ease of use, requiring no packaging. Solid formats can be either anhydrous or low-water content. Like powders, they can be used in a variety of ways: applied directly to the body, or diluted with water to obtain a creamier texture. This article looks at the formulation of solids for these two applications. 

So how do you formulate these different galenics while maintaining the naturality of the formula?

Ensure the stability of a formulation with less or no water

Maintain stability of vegetal oils over time

The stability of a formula, whether composed of less water or totally anhydrous, is subject to challenges due to the high concentration of oil. As the quest for naturality grows, cosmetic formulations are increasingly composed of natural ingredients. For oily formats or balms, naturality is often sought after, particularly in terms of oils, the main component in their formulation. This is why formulators are increasingly turning to the use of vegetable oils, to enhance the naturality of oil and balm galenics. 

Composed of fatty acids, vegetable oils can degrade under certain conditions, such as the effect of heat, light, the presence of oxygen or even in contact with other components. The oxidative potential of the oil depends on its type  and concentration of fatty acids. As the number of double bonds in the fatty acid increases, so does the rate of oxidation, due to the ease with which oxygen molecules in the air can bind to free carbons. This oxidation leads to a change in the appearance of the vegetable oil, which is not sought-after during cosmetic formulation. 

The EMOGREEN™ range brings together high-purity alkanes that are 100% of natural origin (ISO 16128) and biodegradable. These emollients are, apolar, and inert, over time, without odor or color. In addition to being an alternative to volatile, viscous silicone oils, Emogreen™ are easy to formulate with a wide range of oils, waxes, esters and fatty alcohols of plant origin, very present in formulations with a high naturality.

Bring consistency to solid formulas

The formulation of solids, in particular, is subject to instability due to their consistency. The main difficulty lies in ensuring the bar's stability during pouring and cooling. This is correlated with the use of ingredients that bring significant consistency to the formula, thus facilitating its solid texture. 

The use of MONTANOV™ 14  (INCI: Myristyl Alcohol & Myristyl Glucoside), an O/W emulsifier of natural origin (ISO 16128), not only emulsifies the oils present in the formula, but also brings significant consistency to the formula and thus stabilizes the bar. What's more, as it is 100% natural in origin, it achieves a high percentage of naturality while facilitating solid formulation.

Facilitate the dilution of powder in water

Finally, the formulation of chassis for dilution, particularly in powder form, is also subject to instability phenomena. To begin with, it is necessary to have a stable powder. The stability issue is based on the range of ingredients used in the dry process, as well as on the particle size of the solids and the powder pouring or compacting stage (if the powder is not in free powder form). 

A second problem arises at the dilution stage, with the need to solubilize the solid particles in water, to ensure good homogeneity and rheology of the final galenic formulation. When water is added, the presence of a texturing agent in the dry chassis ensures that the formula is given consistency and texture. The use of gums, such as xanthan gum, widely used as an aqueous phase thickener, with a rapid dispersion capacity, facilitates gel deployment when this aqueous phase is added.

To ensure the formation of the final texture, with the desired viscosity, we offer SOLAGUM™ AX (INCI: Xanthan Gum and Acacia Senegal Gum) a natural polymer (ISO 16128) in powder form derived from an association between two gums. Dispersible in both water and oil, and above all with a faster dispersion capacity than xanthan gum, it thickens the formula when hot or cold water is added. This thickening effect promotes stabilization of the oil phase with the water phase.  It is also highly resistant to electrolytes (very important properties for powders that may be loaded with stressful active ingredients), has good suspending power, and gives the formula a more pleasant sensoriality than xanthan gum (easy spreading, soft, non-sticky finish, no soapy effect). Its powder format also facilitates the development of dilutable powder formulations.

Improve the sensoriality of the final formula during formulation without water

Limit the greasy finish for formula with less or no water

The absence of water in the formulation is compensated for by the addition of fattier compounds such as butters or oils. These compounds can have a direct impact on the final feel during application, whatever the type of galenic formulation (butter, oil or even solid). The amount of oil phase in the galenic formulation, as well as the nature and quantity of fats present in the formula, all play a part in how the product feels on the skin. The oily feel of the formula is correlated with the volatility of the oil. Vegetable oils, mainly used for greater naturalness, have a lower volatility than silicones or mineral oils, resulting in a material that stays on the skin longer, leading to a richer, greasier finish. This greasy feel at the end of the spreading process can be a red-flag for end-consumers, who want a light, non-greasy finish for the products they use every day. Constructing the fatty phase by combining different types of oils is the formulator's most important task. The key is to strike the right balance between vegetable oils (fatty/heavy), mineral oils (more volatile) and synthetic oils (lighter), while preserving both feel and naturalness.

Bring a matte skin finish

In addition to a greasy feel, anhydrous formulations can lead to a shiny appearance on the skin. This shine is acceptable for some formulations, but not for all. In the latter case, to limit shine, research into the shine index of emollients used in the formula enables those with a lower index to be chosen. Shine must be measured both in the short term (1 minute after application) and over the long term. The choice of emulsifiers can also influence shine. By choosing emulsifiers with a matte finish on application, the shine of the final formula can be reduced. A formula that is shiny on application or in the jar will not necessarily be so after penetration, thus meeting the expectations of the end consumer.

Discover EMOGREEN™ L19 (INCI: C15-19 Alkane), an alternative to volatile silicone oils, offering both a light touch on the skin and a non-greasy finish for optimal sensoriality of your formulations with less or no water.

Facilitate the use of active ingredients in formulations containing less or no water

Use of liposoluble active ingredients

In order to create a formula with one or more skin benefits, the presence of active ingredients in the formulation is required. However, for the development of galenic oils, balms or solids, the active ingredients must be liposoluble or dispersible in oils, in order to promote good miscibility between the active ingredient and the main oily phase. The challenge is therefore to find the right active ingredient, adapted to the formula brief, being either liposoluble or dispersible, thereby reducing the choice for the formulator.

CERAMOSIDES™ HP (INCI: Glycosphingolipids - Glycolipids), an active in powder form, dispersible in oils, is suitable for formulating butters, oils and even anhydrous solids, while conferring anti-aging, moisturizing and skin protection benefits.

Addition of heat resistant active ingredients

Another challenge encountered when formulating with an oily phase is the heating required in some cases to melt the raw materials and promote their miscibility. However, when adding active ingredients, excessive heating temperatures (up to 80°C in some cases) can lead to their degradation, resulting in a loss of efficacy and benefits. It may therefore be advisable to add the active ingredients once the oil phase has begun to cool, when formulating oils. For the formulation of solids, it is not possible to add the active ingredient(s) while the oil phase is cooling, as the latter will solidify, preventing good miscibility of the active ingredients with the main phase. To facilitate the formulation of these galenics, it is possible to use heat-resistant (and liposoluble) active ingredients, whose chemical structure enables them to resist to the contact with a hot oil phase, while maintaining their properties. These active ingredients guarantee the formula's stability and efficacy over time.

ANTILEUKINE 6™ (INCI: Caprylic/Capric Triglycerides - Laminaria Ochroleuca Extract Oil) is a liposoluble active ingredient, bio-inspired from Laminaria ochroleuca algae, suitable for the formulation of concentrates as well as anhydrous galenics such as butters, which can be added to the oil phase immediately after its heating stage, without waiting for it to cool. Its thermoresistance enables it to retain its properties, even when in contact with a hot oil phase, and to strengthen and soothe the skin, while acting as a shield against external stresses. The use of Antileukine 6™ reduces the depth of dehydration wrinkles by -9%, while delivering +84% hydration to epidermal cells.

To meet the growing demand for cosmetics that combine naturality and responsibility, Seppic offers you its formulation expertise, to inspire you in the development of galenic formulations that use less or no water. This article presents our advice on the challenges posed by more natural and less water-intensive formulations, in order to guarantee efficacy and sensoriality in your formulas. For more inspiration, check out our article dedicated to formulas!

Sources

¹ World Resources Institute

² Thearthandi