Comparison of 1,3-Propanediol and 1,2-Hexanediol

Both 1,3-Propanediol and 1,2-Hexanediol are versatile ingredients commonly used in cosmetic formulations, sharing some similar functions while also offering distinct benefits.

Shared Functions:

• Solvents: Both act as effective solvents for dissolving other ingredients in a formulation.
• Humectants: They help attract and retain moisture in the skin, contributing to hydration.
• Preservative Boosters: Both can enhance the efficacy of preservatives, potentially allowing for lower concentrations of traditional preservatives or contributing to "preservative-free" formulations.

Key Differences and Specific Benefits:

• 1,3-Propanediol:
  • Often derived from natural sources (e.g., fermentation of glucose).
  • Known for providing a pleasant skin feel.
  • Can enhance the moisturizing effect of Glycerin when used together.
  • Typically used at concentrations of 1-20%.
• 1,2-Hexanediol:
  • Acts as a strong preservative booster and can effectively control microbial growth (demonstrated by passing challenge tests).
  • Functions as a penetration enhancer, helping other active ingredients absorb better into the skin.
  • Can help reduce the particle size in emulsions, leading to smoother textures and better absorption.
  • May increase the efficacy of sunscreen formulas.
  • Typically used at concentrations of 1-10% depending on the desired benefit.

Can they be used together?

Yes, 1,3-Propanediol and 1,2-Hexanediol can generally be used together in the same formulation. Their shared and distinct properties can be leveraged to achieve specific formulation goals, such as enhanced hydration, improved ingredient delivery, and robust microbial protection. When combining them, it's important to consider the recommended usage rate for each ingredient and the overall composition of the formula to ensure stability and desired performance.

In summary, while both are excellent humectants, solvents, and preservative boosters, 1,2-Hexanediol offers stronger antimicrobial support and penetration enhancement, whereas 1,3-Propanediol provides a natural option with good skin feel and synergy with Glycerin.