Squalane: A Breakthrough in Skincare and Cosmetic Chemistry

Introduction

Squalane has become one of the most prominent ingredients in the world of skincare and cosmetic formulations. Originating as a derivative of squalene, squalane has gained significant attention due to its impressive emollient properties and biocompatibility with human skin. Initially found in high quantities in shark liver oil, squalane is now commonly sourced from plants, marking a shift towards more sustainable production methods. For chemists and formulators, understanding squalane’s molecular structure, properties, and diverse applications is essential in advancing the development of skincare products. This article delves into the chemical nature of squalane, its main components, key uses, and the best practices for its storage.

Figure 1 Characteristics of Squalane

Chemical Properties of Squalane

Chemically, squalane is a fully saturated hydrocarbon with the formula C₃₀H₆₂, derived from the hydrogenation of squalene, an unsaturated hydrocarbon. The hydrogenation process transforms squalene’s double bonds into single bonds, rendering squalane a stable, non-oxidizable molecule. This stability is crucial for its long shelf life and resilience against oxidative degradation, making it ideal for cosmetic formulations.

Squalane exists as a colorless, odorless, non-comedogenic, and non-polar substance. Its molecular structure consists of a long branched hydrocarbon chain, which mimics the structure of lipids naturally present in the skin. The hydrophobic nature of squalane allows it to form a thin, protective barrier on the skin, preventing moisture loss while promoting skin elasticity.

One of the key advantages of squalane over squalene is its saturation. Squalane’s lack of double bonds makes it resistant to oxidation, which is particularly beneficial for cosmetic products that are exposed to air and light. This stability also contributes to its hypoallergenic nature, making squalane suitable for sensitive and acne-prone skin.

Main Components of Squalane

Though squalane is a simple hydrocarbon, its main component is highly significant: 100% pure squalane (C₃₀H₆₂). The chemical simplicity is one of the factors contributing to its versatility and safety. The squalane used in cosmetic applications is usually sourced from plants, with common sources including:

Olives: Olive-derived squalane is highly sought after due to its abundance and sustainable cultivation. The extraction process is eco-friendly, further contributing to the “green chemistry” approach in modern formulations.

Sugarcane: Another popular plant source, sugarcane-based squalane, has become increasingly popular due to its renewable nature. The process of deriving squalane from sugarcane involves fermenting the sugarcane biomass and converting it into hydrocarbons.

Amaranth: While less common than olive and sugarcane, amaranth seeds also serve as a source of squalane, offering another plant-based alternative.

Historically, squalane was harvested from shark liver oil, which posed environmental and ethical concerns. However, the shift to plant-based sources reflects a growing demand for cruelty-free and sustainable ingredients in the cosmetic industry.

Uses of Squalane in Cosmetic and Skincare Products

Squalane’s versatility and beneficial properties have earned it a place in a wide range of skincare and cosmetic products. The substance functions primarily as an emollient, moisturizer, and carrier oil, but its uses extend beyond these roles.

Moisturizers: Squalane is highly effective in reducing transepidermal water loss (TEWL), which makes it a popular ingredient in moisturizers. Its skin-identical lipid structure allows it to integrate seamlessly with the stratum corneum, helping to maintain skin hydration levels.

Anti-Aging Formulations: Due to its ability to mimic the skin’s natural oils, squalane is often found in anti-aging serums and creams. It helps restore skin elasticity, smoothing the appearance of fine lines, and providing a plumping effect without clogging pores. The oxidative stability of squalane also makes it an ideal candidate for antioxidant formulations.

Sunscreens: Squalane is a common ingredient in sunscreens and after-sun care products. It enhances the skin’s ability to recover from UV exposure by promoting cell regeneration and reducing inflammation.

Cleansers and Makeup Removers: Because of its non-comedogenic properties, squalane is widely used in facial cleansers and makeup removers. Its lightweight texture allows it to dissolve makeup and impurities without stripping the skin of essential moisture.

Hair Care: Squalane is increasingly found in hair care products, where it is used to condition and protect hair fibers. Its ability to penetrate the hair shaft helps to lock in moisture, making it a valuable addition to shampoos, conditioners, and hair masks.

Lip Care: Squalane is also featured in lip balms and treatments, where it helps prevent chapping by creating a protective, moisturizing barrier on the lips.

Squalane’s versatility extends to pharmaceutical applications as well, where it is used as an excipient in drug formulations due to its compatibility with human tissues.

Storage and Stability of Squalane

Squalane’s chemical structure, being fully saturated, makes it highly stable and resistant to oxidation. This gives it a significant advantage over other natural oils that tend to degrade when exposed to air and light. However, proper storage conditions are still crucial to maintaining its effectiveness.

Temperature: Squalane should be stored in a cool environment, away from direct sunlight or high temperatures. Although it is stable at room temperature, prolonged exposure to heat may affect its texture and reduce its efficacy in formulations.

Packaging: As with most cosmetic ingredients, the packaging for squalane should be airtight and made from materials that do not react with the hydrocarbon chains. Amber glass or opaque containers are commonly used to protect it from light exposure, which can slightly alter its physical properties over time.

Shelf Life: The shelf life of squalane can extend up to two years if stored properly. Its oxidative stability means it is less likely to go rancid compared to other oils, ensuring that formulations containing squalane remain effective throughout their intended use period.

Handling: When incorporating squalane into formulations, it is essential to ensure minimal exposure to air and contaminants. This reduces the risk of contamination that could affect the overall stability of the end product.

Reference

[1] Kim S K, Karadeniz F. Biological importance and applications of squalene and squalane[J]. Advances in food and nutrition research, 2012, 65: 223-233.

[2] Allison A C. Squalene and squalane emulsions as adjuvants[J]. Methods, 1999, 19(1): 87-93.

You may like