Introduction

The skin is the largest and outermost organ in the human body and provides protection for the body from the outside environment. Part of that protection involves protection from the oxidative stress from UV-induced radiation which causes tissue damage and premature skin aging. Anti-oxidant components contained within the skin are responsible for the skin’s anti-oxidant defence^​1​.

Ferulic acid is an organic acid that is widely found in vegetables, fruits and some beverages (eg. beer and coffee)^​2​. The biological activity and numerous skin care benefits of ferulic acid are related to its antioxidant properties^​2​. Its reported biological activities include antimicrobial, anti-inflammatory, anti-cancer and other anti-oxidant protective effects.

“Although ferulic acid is daily introduced with the diet, its skin bioavailability after oral administration is really poor. It is necessary to realise a system able to protect ferulic acid and to efficiently deliver the active compound through skin.”^​3​

Poor formulation stability due to oxidation and poor skin permeation from traditional skincare formulations have limited its use in traditional skincare formulations.^​3​

Skin Benefits of Ferulic Acid Application

“Ferulic acid has been recognized as an important chemical structure serving several biological activities, including antioxidant, anti-inflammatory, antiviral, antiallergic, antimicrobial, antithrombotic, anticarcinogenic, and hepatoprotective actions, directly or indirectly.”^​4​

The following is a list of some of the known skincare benefits provided by topical application of ferulic acid. A more comprehensive list recently became available.^​4​

Anti-aging Activity – Collagen Protection

Ferulic acid has strong anti-oxidant activity and can eliminate the action of free radicals in damaging the skin. UVA radiation induced free radicals can cause clinical, biochemical and histological changes in the skin through changes in cells and in extracellular matrix proteins, including collagen, responsible for the structural integrity of the skin. These changes cause premature skin aging and can lead to increased risk of skin cancer. The natural aging of the skin associated with the action of free radicals causes a reduction in skin hydration, pigmentation, fine wrinkles. Another change is the reduction of dermal collagen that makes the skin thinner. Ferulic acid has a protective role for the main skin structures: keratinocytes, fibroblasts, collagen, elastin. It inhibits melanogenesis, enhances angiogenesis, and accelerates wound healing^​5​.

UV Radiation Protection

Topically applied caffeic acid and ferulic acid have beed demonstrated provide protection against UV radiation-induced skin damage^​6​. Further, skin permeation was not influenced by formulation pH. Ferulic acid also has UV absorbing properties which allows it to protect light sensitive tissues from UV oxidative damage.^​2​

“Given that UV radiation penetrates deeply into the skin, topically applied antioxidant drugs can afford to the skin a satisfactory photoprotection only if they are able to reach deeper cutaneous layers, permeating through the stratum corneum”.^​6​

Antimicrobial Activity

Ferulic acid has pronounced antimicrobial activities in cosmetic formulation showing antimicrobial effect against various micro-organisms studied. It displays a wide spectrum of antimicrobial activities, exhibiting effects against yeasts and Gram-positive and Gram-negative bacteria^​2​.

Stabilising Activity of Skin Vitamins

“This study demonstrates that a combination of physiologic antioxidant vitamins C and E, stabilized by a powerful plant antioxidant, ferulic acid, can be applied topically to skin and supplement the skin’s own antioxidant pool to protect against UV-induced oxidative damage.”^​7​

Ferulic acid enhances the skincare effects of Vitamin C and Vitamin E when used in combined action^​7,8​. It was shown to improve stability of these vitamins and double the photoprotection over that achieved by individual vitamins. A combination formula of Vitamin E and Vitamin C offered a 4-fold increase in photoprotection from solar-stimulated radiation. Addition of ferulic acid to the same formula increased photoprotection to approximately 8-fold.^​8​

Sunscreen Enhancement Effects

“A synergic effect between the natural polyphenol (ferulic acid) and the UV filters was evidenced, as well as, FA increased in vivo SPF in 37% and the UVA protection factor (UVA-PF) in 26%.”^​9​

The addition of antioxidants, such as ferulic acid, in sunscreens improves their sun protection factor (SPF) and can prevent inflammatory reactions^​9​. These results provide a new perspective for the development of multifunctional bioactive sunscreens using ferulic acid as a new platform.

Discussion

“Ferulic acid is a potent antioxidant compound that can be used for the treatment of skin damages. However, the great instability of this active compound led to a reduction of its use from skin care industries.”^​3​

Ferulic acid offers proven anti-aging skincare benefits, has low toxicity and possesses many physiological functions (anti-inflammatory, antioxidant, antimicrobial activity, anticancer)^​5​. However, having strong anti-oxidant properties means its use in traditional skincare formulations has been limited by its tendency to oxidise and degrade in formulation^​3,5​.To effectively realise these skincare benefits, formulation stability and skin penetration of ferulic acid need to be improved from traditional skincare formulations. Recent advances in microemulsion formulations have proved that these can stabilise ferulic acid in formula, enhance skin permeation and improve anti-oxidant performance in topical application^​10,11​.

“Advances in nanotechnology have opened new opportunities for the delivery of molecules to the hair follicle as they can accumulate into these structures releasing drugs for an extended period.”^​12​

Formulation Enhancement of Ferulic Acid Activity

“Ferulic acid exerts an important activity in several formulations for topical application that improved the stability and bioavailability when combined with new technologies and methods.”^​11​

Next generation formulation methods using nano-encapsulation have proved able to enhance stability and skin permeation capability of ferulic acid ^​3,11​. Using nano-encapsulation formulation techniques such as microemulsions provides the means to fully utilise and even enhance the powerful anti-oxidant properties^​3​ of ferulic acid in topical application. Our Vitamin C Serum and our C E Ferulic Serum contain both ferulic and caffeic acids in a microemulsion based formulation. Our nano-encapsulated Green Micelle™ formulations increase formulation stability of ferulic acid and enhance skin permeation for superior UV anti-aging protection.

“Increased attention has been paid to nanomedicine as a method of applying antioxidants topically”.^​1​

References