Dispenser technology without preservatives

Preservatives are still understood as being essential components of cosmetic formulations as they are an important means to ensure product stability and shelf life and play a key role in consumer safety. However, they become increasingly out of favour and the awareness of finding alternatives in the cosmetic industry grows steadily.

It is well-known that preservatives can cause various allergic reactions such as atopic or contact dermatitis1,2. They can have negative effects on the microbiome of the skin and can damage human epithelial cells. 

In a study conducted by D. Pinto, et. al.3 it has been stated that the application of cosmetic products to the skin can alter the balance of the skin microbiota, compromising the eubiosis of the skin, mucous membranes, and the scalp. This impairment may be attributed to many factors including the residual activity of the preservatives on the skin since they remain active in products after these have been applied to the skin.

Upset the balance

Actually, the skin is a perfect example for a natural homeostasis of harmless and/or beneficial microorganisms and their host environment. This homeostasis is subject to change if preservatives are applied, whose intention is the protection against microbiological contamination.

Indeed, preservatives can interact with microbes present in this environment changing the amount of the balance of the bacterial population. In an article written by P. Pascal4, he raised the
question of how products can protect users against microbial contamination, and at the same time respect the skin microbiome, microbial diversity, and balance. The answer is to design products that provide protection against microbial contamination while minimising the quantities of preservatives used in the formulations.

Free from

Health authorities around the world recommend the development and use of preservative-free dermal products and the need to focus on new technologies is very present these days. The development of airless dispensers was the first step in the right direction to realise new and innovative product concepts, minimising the percentage of used preserving agents in cosmetic formulations. We need to understand that all ingredients that inhibit the growth of germs are preserving agents and not only those that utilise this function primarily.

Pentylene glycol, several alcohols or even magnolia extract, for example, can be used in cosmetic products in Europe for preserving the formulation without the need to declare them accordingly (EC Regulation1223/2009, Anmex V). If those kinds of formulations are then fil-led in innovative airless packaging solutions, the consumer would understand the claim “preservative-free” as being true, which is not the case, unfortunately. With most of the current used packaging solutions and the respective manufacturing processes, a claim like “100% free from preservatives” cannot be achieved.

Dispensing technologies

New technologies are necessary to offer a true alternative for preserving ingredients in cosmetics. The combination of high-end technologies in dosage systems and innovative manufacturing conditions, as 
the “Ultra High Temperature (UHT) process, have good chances to become the gold standard for “real” preservative-free products in the cosmetic industry. 

A special airless dosage system5 for dispensing very sensitive liquid or semi-solid formulations permits
avoiding any kind of preservatives, even after the product has been opened, as the special design of the system prevents contamination. Both a microbiologically tight closing valve and the bacteriostatic effect of the surfaces used in the nozzle guarantee perfectly protected contents.

A microbiologically tight valve is technically very complex regarding the minimum permissible manufacturing tolerances of the individual components and physically requires a high opening pressure, because the smoother the valve for the product outlet, the easier it is for germs to overcome the valve and enter the bottle.

The bacteriostatic effect is achieved by a silver-based additive. This prevents biofilm formation on the surface. Additionally, the flexible airless inner bag that folds when the vacuum emerges due to pressing the pump, dispenses the content without being in touch with any oxygen. This leads to a proven perfect protection of the preservative-free contents.

The “Ultra High Temperature” (UHT) technology that is used during the aseptic manufacturing process rounds off the modern technology to provide products that are 100% free from preservatives. UHT sterilisation known as the process of heating milk or cream to temperatures exceeding 275°F (135°C) for one or two seconds, then packaging it in a hermetically sealed container.

Conclusion

Eliminating dispensable ingredients and guaranteeing safety against microbial contamination has many advantages, for example for sensitive and allergy-prone skin but it also represents the ever-increasing trend of pure and essential cosmetics.