High purity squalene for pharmaceutical and cosmetic applications via metal-free nitrogen-deletion coupling

Background

Squalene is a naturally occurring triterpene hydrocarbon that plays a crucial role in various industries, particularly pharmaceuticals, cosmetics, and vaccine development. Traditionally, squalene has been sourced from animal origins, such as shark liver oil, and from certain plants like olives. However, these natural sources present significant challenges: animal-derived squalene raises sustainability and ethical concerns, while plant-derived squalene is limited by low yield and agricultural variability. Furthermore, the increasing demand for squalene in high-value applications—especially as an adjuvant in vaccines and as an excipient in drug delivery systems—has highlighted the need for a reliable, high-purity, and scalable supply that is free from contaminants and suitable for sensitive pharmaceutical uses.

Current approaches to obtaining squalene primarily rely on extraction and purification from natural sources, processes that are often inefficient, labor-intensive, and unable to consistently achieve the high purity standards required for pharmaceutical applications. These methods can introduce impurities, including heavy metals, pathogens, or allergenic substances, and often result in squalene products with undesirable isomeric forms or residual contaminants. Synthetic routes that have been explored to date frequently depend on starting materials that are themselves mixtures of isomers, or they require transition metal catalysts, which can leave trace metal residues and complicate purification. As a result, the industry faces persistent challenges in producing squalene that meets stringent quality and safety requirements, underscoring the need for alternative synthetic strategies that can deliver high-purity squalene efficiently and sustainably.

Technology

This technology presents a fully synthetic process for producing high purity squalene, a valuable triterpene hydrocarbon used extensively in pharmaceuticals, cosmetics, and vaccine adjuvants. The method begins with pure trans, trans-farnesol, which is converted into a bis-farnesylamine intermediate through a sequence involving p-toluenesulfonamide and cyanomethylenetributylphosphorane, followed by reduction with sodium naphthalenide. The bis-farnesylamine is then subjected to a reaction with Levin’s anomeric amide reagent, which induces deamination and generates carbon-centered radicals. These radicals undergo spontaneous coupling to form squalene, all without the use of transition metal catalysts. The resulting squalene is a clear, colorless or light yellow oil with purity exceeding 97%—typically above 98%—and contains less than 1 ppm heavy metals, making it suitable for high-grade pharmaceutical and cosmetic applications.

What differentiates this technology is its ability to produce squalene of exceptional purity and consistency, overcoming the limitations of traditional extraction from animal or plant sources, which are often unsustainable, inefficient, and yield products contaminated with impurities or heavy metals. By employing a precise synthetic route that avoids isomeric impurities and transition metal catalysts, the process ensures that the final product is free from contaminants and suitable for sensitive applications such as vaccine adjuvants and advanced drug delivery systems. The use of pure trans, trans-farnesol as a starting material, coupled with the innovative radical coupling strategy facilitated by Levin’s anomeric amide reagent, enables a streamlined synthesis with fewer steps and higher yields. This approach not only meets the growing demand for pharmaceutical-grade squalene but also provides a scalable, sustainable, and reproducible solution that sets a new standard for quality and safety in squalene production.

Benefits

• Produces high purity squalene (>97%, preferably >98%) suitable for pharmaceutical use
• Eliminates heavy metal contamination (<1 ppm) by avoiding transition metal catalysts
• Ensures product free from geometrical and positional isomers for consistent quality
• Utilizes a sustainable, fully synthetic route independent of animal or plant sources
• Enables scalable and efficient synthesis via radical coupling of bis-farnesylamine
• Improves safety and efficacy in applications such as vaccine adjuvants, drug delivery, cosmetics, and lipid nanoparticles
• Reduces risk of contaminants like pathogens and allergens associated with natural extraction

Applications

• Vaccine adjuvant manufacturing
• Pharmaceutical drug delivery systems
• Cosmetic emollient formulations
• Lipid nanoparticle production

Additional info

This chemical synthesis produces high-purity squalene (>97%, <1 ppm heavy metals, isomer-free) from trans, trans-farnesol. The process converts farnesol into a bis-farnesylamine intermediate, which then undergoes deamination and radical-radical coupling using Levin’s anomeric amide reagent. This method avoids transition metal catalysts, yielding a pharmaceutical-grade triterpene hydrocarbon suitable for high-grade applications.