Introduction

Combining Vitamin C and Vitamin E in a single combined treatment has proven to provide synergistic skincare benefits over and above those of individual vitamin treatments. However, combining water soluble Vitamin C with oil soluble Vitamin E in a stable and effective formulation presents a number of problems^​1​. Very few existing Vitamin C/E skincare formulations are effective because they have not satisfactorily addressed these problems.

“Although many cosmeceutical formulations contain Vitamin C and/or Vitamin E, very few are actually effective in topical application. First because of low concentration, second because stability is compromised and third because the form of the molecule is not absorbed by the skin”^​1​

The Problems

1. Stability

The biggest challenge is formulating with Vitamin C is to maintain it’s stability^​2​. Vitamin C is easily degraded in water solution at high pH by water, oxygen, heat, light and metal ions. Whilst a number of strategies have been tried to improve Vitamin C stability, it remains a serious formulating challenge.

2. Skin Penetration

Vitamin C, as the L-Ascorbic form, is an acidic molecule that cannot penetrate the skinu nder normal circumstances with less than 1% of the topical dose entering the skin^​3​. The formulation must have an acidic pH of less than 3.5 for L-Ascorbic to be able to penetrate the skin at all^​4​.

The Solution – Nano-emulsions

Microemulsions (also called Nanoemulsions) and oil and water complex formulations employed to optimise delivery of many cosmetic and pharmaceutical actives^​2​. They consist of very small droplet size (10-100nm) micelle solutions of oil soluble droplets in a water substrate. Microemulsions are characterised as being chemically stable, suited for combining oil and water active ingredients and better able to penetrate the stratum corneum than other formulation types^​5​.

“In cosmetics formulation, nano-emulsions provide rapid penetration and active transport of active ingredients and hydration to the skin.”^​5​

In recent years, microemulsions have been successfully formulated to combine Vitamin C and Vitamin E in single, stable cosmetic formulations^​2​. These microemulsions have been shown to deliver the synergistic benefits of Vitamin C and Vitamin E in a combined skincare treatment. The stability of both Vitamin C and Vitamin E was enhanced by inclusion in a microemulsion formulation^​6​. Microemulsion formulations were also found to increase the skin penetration of both vitamins^​7​. Scientists have shown that incorporation of Vitamin C and Vitamin E in microemulsion formulations enhanced stability of both vitamins as the microemulsion structure provides greater ingredient protection^​6​.

Discussion

Our proprietary Green Micelle™ nano-emulsion formulation system uses organic ingredients to form nano-encapsulating micelles that combine Vitamin C and Vitamin E in a stable serum. Because our organic serums use our new generation nano-formulations they enhance ingredient formula stability and have superior skin penetrating capabilities.

References