Preservative Values

One of the most emotive issues in cosmetics is the desire for natural materials and the avoidance of synthetics.  Various campaigns have indicated that cosmetics are toxic time bombs and can do a lot of harm.  All cosmetics produced in Europe by law have to list their ingredients.  Preservatives are used in small amounts and as INCI lists are written in descending order of content, they normally appear at the end of the INCI listing, with long, complicated chemical sounding names. In the Health Food shops, there are often products that claim to be preservative free or contain natural preservatives.  How can that be?

Creams, lotions, oils, cosmetics are rarely used fresh – i.e. used within hours of manufacture.  Such items that appear on our bathroom shelves, dressing table, drawers etc. in real life are not looked after very well.  If we like and favour natural cosmetics, we have to understand that all living natural substances degrade, go off.  Fruit left in a bowl for a long time goes mouldy, butter goes rancid, bread gets mould – we have all seen this.  The natural state of raw materials once they are harvested or gathered is to degrade.  When we have food in our homes we have to preserve it.  We can do so by pickling, by refrigeration, by drying, by using preservatives such as alcohol.  Many of the foodstuffs we buy from supermarkets have small amounts of preservatives added to them. These are taken into our bodies and much of the objection to preservatives is based upon these preservatives in the food chain.  Strangely enough, such intake of toxic substances does not get the publicity that preservatives in cosmetics do.

All around us, unseen, are bacteria – yeasts, moulds and fungi, some good some bad.  When we put our fingers into a pot of cream we put bacteria into that pot.  When we open a pot of cream, even to look at it, bacteria will find their way into that pot.  When we open a bottle of oil the air, being full of the spores of yeasts, moulds and fungi, will contaminate the oil.  Most importantly, from the point of oil, air itself is made up of gases, one of which is oxygen and oxygen burns and degrades oil.  All these processes are natural, but we have to realise with clear minds that this is real nature, this is what happens in real life.  Nature goes off and so natural cosmetics will go off unless there is a preservative.

The ideal preservative does not exist.  By their very nature preservatives kill things.  As no single ideal preservative exists manufacturers tend to mix them together using a preservative system.

Most cosmetics consist of water and oil as an emulsion.  Water supports bacteria growth, oil does not but oil can support yeasts, moulds and fungi as may also water.  Oils are prone to oxidation and rancidity.  The more an oil is unsaturated the more likely it is to go bad.

Demand for effective and safe preservatives has never been higher, but with consumers and regulators alike turning against some well used and preferred synthetic preservatives the industry has to find alternatives. There is a preservative crisis little known outside the industry. Regulated restricted lists of preservatives are closed and with testing bans it is difficult to develop new and safer preservatives. A cosmetic product is expected to have at least a 30-month shelf life.

Whilst many essential oils have an antimicrobial function they are mostly not registered in any regulatory format as a preservative. Standard tests exist such as the challenge test (ISO11930:2012) whereby the specified microbes must be rapidly killed. If they pass the test, then thee product has a preservative element and it would be misleading to say the product has no preservative. With more interest in the biome and skin bacteria preservation there is interest in creating a hostile environment for pathogenic bacteria. It is in this area that essential oils are considered but this is controversial especially if misleading claims are made such as ‘preservative free’ when it has a preservative action but the reason for its addition is touted for its fragrance rather than its activity. Such dual action needs some explanation and clarification.

© FEI

JK 2017

THE PROCESS OF EXTRACTION

The term herbal or plant extract is used a lot in articles, books and catalogues but what is an extract? Is it the same as the original herb or plant? Or is it something different?

Extraction is like the art of making tea.

A solvent is used to extract elements or compounds from the plant or herb but which the extractor may call the drug. Each herb or plant contains lots of different chemicals such as vitamins, minerals or other components. These are called the actives i.e. the molecules that do the work for which the herb is renowned such as pain killing or reducing inflammation.

It follows then that the type of solvent determines the nature of the extract. Different chemicals in the herb or plant engage with different solvents. There are for example water soluble components, oil soluble components etc.  A variety of solvents may be used each of which has its own advantage or disadvantage and each of which is poor or better at extracting a certain component.

Some solvents have secondary effects e.g. alcohol or propylene glycol which have preservative properties.  Solvents are not necessarily interchangeable.

The solvent has a maximum carrying ability.  Once saturated the solvent cannot take up any more of the chemistry of the plant. This is the best sort of extract. Using the example of tea again you can make weak tea or strong tea so not all extracts are the same value and this is sometimes reflected in the price of a product. Weak tea goes further! Many times extracts are not added for efficacy but rather to make a product look as though it contains lots of useful items.

As noted above, an extract can be made whereby the solvent is not saturated but rather the solvent (relatively cheap) is in effect “tainted” by a plant rather than being “full” of plant.  This is a cheap way of making extracts whereby only a small or insubstantial volume of plant material is used.  Alternatively, old material is used or re-used.

These cheap extracts should not be compared with a standardised extract.  Such an extract is where a key component is certain to be present at a given level.  A common or average is found and the extract adjusted to comply.  A common means of measuring the key molecule or component present is by UV spectroscopy.

This component or tracer can be further concentrated or filtrated to a reproducible or measurable componency (also referred to as a standard extract but more correctly concentrated standard extract).  Purified extracts refer to the highest levels of certain molecules.  Perhaps other synergistic molecules are maintained to increase the activity of the plant drug.

Herbal specification data mostly mentions the quantity of plant used such as organic or other status and the dry residue as a point of reference and therefore standardisation of quality.  The quality of an extract is solely linked to its concentration or containment of active principles.  These can only be measured through proper analysis.

So not all extracts are the same in value. Seeing a herbal name on the back of a pack (the INCI list) tells you little about the real quality or value of an extract, the good, the bad and the ugly all have the same name. Price becomes some guide as does the brand name which builds trust with its promotional material. Read the core values of a brand and its claims which may even tell you the value of the extracts used.