Skin conditions and disorders commonly seen in clinic today all seem to have one common denominator in that they all suffer from barrier disorders that may be as simple as essential fatty acid deficiency, through to the more difficult to treat rosacea.
We have learnt in recent years about the ‘wash out’ effect of essential skin lipids caused by common anionic and cationic emulsifiers are contributing to this increase in barrier disordered skin.
How is skin barrier defense reduced by the daily application of something that was supposed to improve and replaced skin lipids?
There has always been a movement towards skin care products that have less chemicals, that are fragrance and preservative free and do not aggravate sensitive skin.
Are we any closer to achieving this?
There is a certainty that skin care products must contain some form of preservatives to keep them safe for use, however the type and amount of preservatives is influenced by quality of formulation, packaging and manufacturing methods. Another overlooked factor in product failure is how the product is treated by the user during its shelf life. This short overview will provide food for thought.
A variety of microorganisms including yeasts, fungi (yeast & mould) and bacteria, including pseudomonas, staphylococci and streptococcus can cause problems with cosmetic preparations over time. Contamination of formulations can lead to separation of emulsions, product discolouration, the formation of gases and odours, as well as the infection of the skin of the user.
Preservatives have a microbicidal or microbiostatic effect on bacteria, yeasts, and mould. Microorganisms do not only threaten the shelf life of a product: when they reproduce they may be a serious risk to the consumer’s health. Health and safety regulations consequently mandate protection for the consumer. Preservatives are not only in our skin care, make-up and toiletries, but also in our food and medications. We are exposed to preservatives on a wider scale than we would like to think.
Why do products fail?
Problems with preservative failure in cosmetics can be related to one or more of the following:
• Expiry of usable shelf life
• Extreme temperature variation during storage
• Incorrect storage conditions
• Incorrect application and usage
Personal care products that are usually stored in bathrooms contain preservatives to protect against the fungus that inhabit warm damp environments. When one considers the way face creams, masks, eye creams and sun protection are applied and stored, then it is easy to understand the need for preservatives.
If the end user were as careful about application methods and storage as the skin treatment therapist is in the clinic, the percentage of preservative could be reduced.
However, this is not the case, and as long as fingers are used to dispense and apply creams, lids are left off containers, products are left unprotected in light, air and water, there is a need for preservatives.
Minimising the use of preservatives
We know that any cosmetic or personal care product that is truly “ preservative free” will still usually carry antioxidants as the preservative ingredients. However, when a product carries the marketing words “fragrance-free” or “preservative free”, they have a higher quality and purity of raw materials and the manufacturing plant may or should have practised “aseptic manufacturing”.
Aseptic manufacturing processes
The term aseptic is defined as preventing infection; free or freed from pathogenic microorganisms; (the methods involved are the most demanding of pharmaceutical manufacturing processes). It requires precise attention to operator training and behaviour, process validation, production process documentation, plant and equipment maintenance and change control management.
Cosmetics claiming the aseptically manufactured certification require the formulations to be manufactured under the most stringent guidelines to prevent any contamination at any time before, during and after the manufacturing process. The combination of aseptic manufacturing and totally sealed packaging relieves the demand for preservatives, as it minimises the potential for contamination.
As you can imagine, adherence to such meticulous processes requires investment in both training and specialised facilities; and reflected in the cost of the product. Many ingenious types of packaging have also been developed to reduce cross-contamination and reduce the need for large quantities of preservatives. However, this innovative and new packaging also comes with a cost.
Jar, dispenser or tube?
Preservatives are indispensable whenever a cosmetic product contains water. Without water, microorganisms can neither reproduce nor live. Pure oils and lipids perhaps require antioxidants to prevent rancidity but no preservatives.
Packing in jars involves a higher germ contamination during the application of the product than with a tube or dispenser packaging. Thus, jar products contain a higher reserve of inhibitors. Furthermore, jar products involve another phenomenon that is quite disagreeable; changes in temperature that happen e.g. when stored in the bathroom may involve condensation residues in the lid.
These water residues are an ideal precondition for the growth of germs due to the presence of traces of inorganic substances.
Hair, grit, skin cells and general debris also accumulate around the inside of the lid to become a breeding ground for bacteria.
Airless dispensers & specialised packaging
The packing in airless dispensers avoids this specific problem as they have a second bottom part that automatically moves up while emptying the receptacle and thus prevents the air from penetrating.
The packaging of “preservative-free” cosmetics would ideally be in airtight pump containers. This type of packaging would ensure that the risk of oxidisation is prevented or reduced.
Depending on the material, tubes pose different conditions.
The good old aluminium tube with its creases makes a pretty poor optical impression; its use, however, is very hygienic because it is impossible that germ-contaminated air penetrates while emptying the tube.
Plastic tubes have the disadvantage of resuming their former shape when emptying which means that they suck in external air into their interior and together with it, germs.
From the hygienic and the appearance standpoint, as well as regarding the lowest possible dosage of preservatives, airless dispensers are becoming the future number one packing material for dermatological and cosmetic products.
Skin conditions most susceptible to preservative reactions
There is a common denominator among skins that show a negative reaction to a product, and most often it is not the product that is at fault
It is generally due to the compromised condition of the skin and would include a loss or reduction in the first line of skin barrier defence, the “acid mantle”.
A skin that has lost the protective “flora” and the emollient and occlusive action of the acid mantle, exhibit the hot, itchy burning signs of eczema and allergic contact dermatitis.
Also, the next two lines of skin barrier defence (multi lamellar lipid and corneocytestructure) may also be compromised leaving the interior of skin susceptible to outside pathogens and allergens.
It is not uncommon for clients with skin irritations to be unaware that it is the condition of their products that can be the cause of the condition. Clients may be unaware that because of poor storage and usage practices, the product has become “unusable” from a safety standpoint and is harbouring bacteria.
Always check the client’s products during the consultation, with particular attention to the state of seals on the packaging and the conditions of storage, and, of course, the use-by date.
Preservatives in cosmetics are usually only in quantities to protect the formula under normal conditions.
However, clients can severely test the effectiveness of the preservatives by a combination of poor storage and application habits.
The disadvantage of all the preservatives generally approved worldwide is their allergenic potential, especially for individuals with chronic skin barrier damages. As the percentage of individuals with compromised skin constantly is on the rise, it is no wonder that the allergy rate also proportionally increases.
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