Creating a cosmetic product can be a challenging and often expensive procedure. Perfecting the balance of your ingredients to create a product that your consumers will love is a difficult task to achieve. Even for those with laboratories at their disposal, they will often struggle to get the desired smell or texture without compromising on the shelf life of the product. For small cosmetic manufacturers, creating products such as skin lotions or eye creams (often from home), the challenge is amplified as frequent lab testing is an expensive and time consuming procedure.

In this blog post, we will be looking at the steps required when creating a cosmetic product, specifically the testing your product will likely need to undergo (depending on your location) and how cosmetic dipslides can drastically cut production time and help you to pass lab testing the 1st time. 

The below information is based on EU/UK laws/guidelines but the principle will be the same no matter where you are in the world (the legal requirements may change but the methods should be the same).

What tests do I need to do on my cosmetics?

Whether you are a small sole trader or a multinational corporation, you will need to produce your product according to GMP (good manufacturing practice) and comply with EU Cosmetics Regulation (EC) 1223/2009*. Without this, your cosmetic product would not only be illegal to sell in the UK/EU but could cause harm to the end user (leaving you with brand damage and potential legal problems).

*this is subject to change as Brexit may mean that the UK develop their own regulations.

What are the types of tests you will need to complete?

When creating a cosmetic product, you will need to run various tests before you can sell your products to the end user. The testing procedures include a Challenge test, a Stability test and a test for the product's Microbiological contamination level (sometimes called batch testing). The latter being one of the most important as if the microbial content is too high, it can cause all other tests to fail. You will likely also want to carry out an In-House Accelerated pre-stability test (IHAPS) (a test you can do yourself) before sending the product off to a lab. Please note, an IHAPS test is not a legal requirement but conducting this test before sending to a laboratory saves time and money in the long term. 

What is a cosmetic challenge test?

In brief, a challenge test (which can only really be done correctly by a laboratory) involves as the name suggests, challenging your product with microbial contamination and seeing if the preservatives can prevent spoilage. The procedure is relatively simple in that various microbiological contaminants (such as Pseudomonas), are manually introduced into your product. Tests are then conducted to see if your preservatives can prevent this contaminant from multiplying (usually over a period of 3-4 weeks). If the levels of the contaminant get too high, your product will fail as your preservative is either not strong enough or non functional.

What is a cosmetic stability test?

A stability test is designed to work out the shelf life of your product and how long it is safe to keep using once opened (e.g. use within 12 month's of opening). There are two types of stability tests, 'real time' and 'accelerated'. Both should be performed in a lab.

Real time stability tests are where a product that is expected to have e.g. 1 year's shelf life, is exposed to elements such as temperature changes for 1 year. After 1 year, the product is checked to make sure that the microbiological levels (as well as other factors such as odour, viscosity etc) are acceptable and at safe levels.

Accelerated stability tests are where a product is subjected to an increased stable temperature (usually 40-45 Degrees C) for 3 months. The product is then checked (like a real time test) to make sure it is still safe to use.

There is also another test called an IHAPS which does not calculate your products shelf life but can help you to achieve the longest shelf life possible for your product. Please 

What is a IHAPS (In House Accelerated Pre-Stability Test)?

An IHAPS test is not a stability test itself and will not tell you the exact shelf life of your product (only an estimate). Instead it is a test designed to help your product to achieve the best possible results from a lab based stability test 1st time (and in turn avoid paying for multiple stability tests). An IHAPS test can be done at home with the correct equipment (see our kits below) and involves placing your product inside a special heated incubator for 3 months at 40 Degrees Celcius. This provides the perfect habitat for bacteria / yeasts and moulds to multiply and grow if they are present in your product. 

The product is then tested throughout the 3 months to see when the product's microbiological levels become too high / over safe limits. When it does, you can then look at the time that has expired and approximately calculate the shelf life of that product. If the IHAPS test gives a much shorter shelf life than expected, you know not to send the product off to the lab and instead re-formulate your product.

Using CRBS dipslides allows you to experiment with your formula to get it correct before sending it off to a laboratory. This method avoids multiple back and forths with laboratories where you end up waiting 4 weeks between cosmetic tests only to be told your cosmetic product either failed a stability test or the shelf life of the product is considerably less than expected. Being able to give your cosmetic product the best chance of passing 1st time not only saves you money on laboratory tests but allows you to get your product to market quicker than your competitors.

How can you check the Microbiological contamination level using CRBS dipslides?

Whilst stability testing and challenge testing are required, you will also need to monitor each batch of your product for microbiological contaminants. Bacteria, yeasts and moulds can cause spoilage in your product and can be introduced from a variety of sources.

For example, your product could have passed the stability and challenge tests but if you rubbed your eye when mixing a batch of your next cream and then touched an ingredients lid, you will have unwittingly transferred some bacteria. Over time, given the right conditions, these bacteria can then multiply and the next time you make a batch, you could touch the lid, pick up your mixing whisk and in turn introduce bacteria into your product. Other methods of introducing bacteria can be as simple as a raw ingredient that already has bacteria in it. Remember no matter how strict you are on your hygiene when creating cosmetics, if your ingredients are already compromised, your end product will also be.

The good news is that there is a very cost efficient way to monitor the microbiological contamination levels of your end product and your ingredients without using a laboratory or paying for additional laboratory testing. To do this, you use a CRBS dipslide.

A CRBS dipslide is a paddle with two different agars on each side (a jelly type of substance). These agars are, in their simplest form, 'food' for bacteria, yeasts and moulds. Using a sterile swab, you would apply a thin, semi-transparent layer of your product over all of the dipslide agar, then place the CRBS slide into an incubator. The incubator raises the temperature to a level that bacteria thrive in and in turn the microbes then starts to grow and 'eat' the agar. Inside the agar is a dye that when consumed by bacteria, turns the bacteria red in colour

After 48 hours, bacteria that was in your sample would show up as red spots (colonies). Counting these spots can tell you your overall bacterial level allowing you to see if your product (or ingredient) has microbiological contamination. After a further 72 hours, it will also tell you if you have any yeasts or moulds in your sample.

Whilst the above may sound confusing to someone who is new to cosmetic testing, it really is as simple as swabbing your product onto the dipslide, placing the dipslide into the incubator then counting the amount of spots. More spots = more contamination. This simple yet efficient way of testing your products / ingredients can save a cosmetic producer a small fortune and more importantly stop a product going to market with contamination.

What do I need to start testing my cosmetics and cosmetic ingredients?

The products you will need are:

• CRBS Cosmetic dipslides (a slide specifically designed for testing cosmetics).
• A dipslide incubator (must be a dipslide incubator. Other styles of incubators often use fans/heat elements which can cause issues with dipslides during incubation).
• Sterile dry swabs (individually sealed in sterile packets).

Due to popular demand we have created two cosmetic test kits which include all the required items and have a discount applied. These kits are

• Cosmetic Test Kit
  This kit can be used to test your products and ingredients for bacteria, yeasts and moulds. It includes our introduction incubator (which can test up to 2 samples at a time), 20 CRBS dipslides and 40 sterile swabs (one swab for each side of the dipslide). It can not be used to perform an IHAPS test due to the size of the incubator.
• Premium Cosmetic Test Kit (coming soon)
  This kit includes a larger incubator, 20 CRBS dipslides, 40 Sterile Swabs and a digital pH Tester. This kits allows you to check the contamination level of your products/ingredients, its pH and allows you to perform an IHAPS test*. Whilst this kit does cost more, the long term savings quickly recover the additional costs.

*depending on the size of your packaged product.

References:

REF : https://ec.europa.eu/health/sites/health/files/endocrine_disruptors/docs/cosmetic_1223_2009_regulation_en.pdf