Mechanisms of Action of Peptide and Market Perception

Can you explain how peptides function at the cellular level to promote skin health?

In the personal care industry, the term ‘peptide’ refers to molecules that are short chain amino acids – very small substances – that are able to traverse to the stratum basale and signal physiological changes at the dermal level; or in some cases, effectively travel into the dermis and compete with neurotransmitter binding sites to temporarily alter a physiological activity. As an example, the botox-like action of a hexapeptide addresses the signs of ageing by inhibiting muscular contractions that disturb the packing of the lipid matrix. If you can stop the contractions, the lipid matrix maintains its profile and deformation of the skin does not occur – you effectively stop the appearance of a wrinkle. This is done by providing a ‘mimic’ peptide in cosmeceutical form which binds in place of the peptide normally produced by the body, to prohibit the muscular contraction. The result – less facial expressions and less wrinkles.

Which specific skin concerns, like ageing (morphological and dyschromic), are most effectively addressed by peptides, and why?

Other peptides perform in similar ways: by blocking peptides normally produced by the body when you don’t want the activity (like wrinkles); or replacing missing peptides that are not produced in sufficient quantities (as occurs through the ageing process). There are peptides available to combat the signs of ageing, whiten the skin and even lengthen the lashes.

There’s a lot of hype around peptides. What are some common myths or misconceptions that you'd like to clarify for both formulators and consumers?

Only a very small amount of peptide is needed to get the required results, as long as the formula enhances delivery to where they need to go! Some consumers think the lower a cosmetic ingredient appears on the label, the less likely it is to work, but when it comes to peptides, that is absolutely not true! These substances are so small that not much is needed to get amazing visible results. As little as 77mcg is all that is clinically required, per application, to get the amazing results with the hexapeptide I mentioned earlier – some other peptides are required in even smaller quantities for other skin or hair benefits.

What are some of the biggest challenges when formulating with peptides, particularly in ensuring stability and efficacy? / What are the primary technical hurdles in formulating stable, active peptide products, and how have recent innovations addressed these?

One of the biggest challenges a Cosmetic Chemist always faces is delivery of an active to the required site. To pass through the stratum corneum (and deeper layers) substances either need to pass through the cells or around them (the intercorneocyte space). Water soluble substances need to be extremely small to traverse the stratum corneum. Lipid soluble substances can travel through lipid bilayers when small, but still have similar distances to travel. Even if they can enter a pathway, they then have an incredibly large distance to travel (compared to their size) to penetrate beyond the stratum corneum.

This is particularly important with the delivery of peptides – they are extremely small and can traverse to the stratum basale and beyond; but compared to their size, since they are extremely small, they need to travel an incredibly HUGE distance – so the vehicle, the product base they are in, becomes an essential component to enable the bulk of their passage through the epidermis. Once they are ‘delivered’ to the stratum basale, their ability to travel into the dermis and make a difference is certain – but getting them there is the hard part.

Standard emulsions are amphiphilic bases, containing both hydrophilic (water) and hydrophobic (lipid) phases as well as amphiphilic substances (the emulsifiers), so act as excellent delivery vehicles for small substances to at least the deeper layers of the stratum corneum. The use of osmolytic substances such as humectants can enable penetration to the stratum granulosum level. To provide the required activity, peptides must be provided to the skin in a suitable carrier base to reach the stratum basale target site - this is usually best achieved using an emulsion (amphiphilic) base combined with humectant agents and/or liposomal delivery agents.

Using key materials to ensure delivery of these actives to the stratum basale will give a competitor product a leading edge over another brand using the same active in the same proportion but in a poor delivery base. This comes down to clever formulating to ensure the best possible visible results for a consumer.

Formulation Challenges and Solutions

What are some of the biggest challenges when formulating with peptides, particularly in ensuring stability and efficacy? / What are the primary technical hurdles in formulating stable, active peptide products, and how have recent innovations addressed these?

One of the biggest challenges a Cosmetic Chemist always faces is delivery of an active to the required site. To pass through the stratum corneum (and deeper layers) substances either need to pass through the cells or around them (the intercorneocyte space). Water soluble substances need to be extremely small to traverse the stratum corneum. Lipid soluble substances can travel through lipid bilayers when small, but still have similar distances to travel. Even if they can enter a pathway, they then have an incredibly large distance to travel (compared to their size) to penetrate beyond the stratum corneum.

This is particularly important with the delivery of peptides – they are extremely small and can traverse to the stratum basale and beyond; but compared to their size, since they are extremely small, they need to travel an incredibly HUGE distance – so the vehicle, the product base they are in, becomes an essential component to enable the bulk of their passage through the epidermis. Once they are ‘delivered’ to the stratum basale, their ability to travel into the dermis and make a difference is certain – but getting them there is the hard part.

Standard emulsions are amphiphilic bases, containing both hydrophilic (water) and hydrophobic (lipid) phases as well as amphiphilic substances (the emulsifiers), so act as excellent delivery vehicles for small substances to at least the deeper layers of the stratum corneum. The use of osmolytic substances such as humectants can enable penetration to the stratum granulosum level. To provide the required activity, peptides must be provided to the skin in a suitable carrier base to reach the stratum basale target site - this is usually best achieved using an emulsion (amphiphilic) base combined with humectant agents and/or liposomal delivery agents.

Using key materials to ensure delivery of these actives to the stratum basale will give a competitor product a leading edge over another brand using the same active in the same proportion but in a poor delivery base. This comes down to clever formulating to ensure the best possible visible results for a consumer.

How to choose the right peptide for cosmetic formulas?

When choosing which peptide to use in a cosmetic formula, follow these rules:

• Review clinical efficacy data for the type of base formula used and input required
• Peptides with the same INCI name from different suppliers will not necessarily yield the same results, so be specific when purchasing peptide ingredients from your cosmetic supplier – choose the one with the efficacy data specific to their material
• Ensure the right input is used and observe any compatibility requirements when putting the cosmetic formula together
• Enhance delivery where possible using clever cosmetic formulation techniques

When you get the right amount of an effective peptide to the deeper layers of the epidermis, you’ll always get great results. Happy formulating!