May 2008

Did you know the average adult has 21 square feet of skin (2 sq m) which weighs 7lb (3.2 kg) and has approximately 300 million skin cells? The skin is one of the largest organs of the body and fulfils many functions such as a barrier function to protect the body from the environment, a temperature regulator, an immune organ to detect infections and a sensory organ to detect temperature, touch and vibration. Understanding our skin and how it interacts with the numerous chemical substances that come in contact with it everyday is a key health issue. To address these concerns Intertek can now offer a range of skin related services which will be presented at the Academy of Pharmaceutical Sciences Skin Forum (June 2008).

Skin Substrate analysis

Most claims regarding the efficacy of personal care products are generally made following user trials, Intertek is able to provide the proof to substantiate the findings of a user trial in a number of different ways. Using a powerful combination of topographical and chemical analysis using a range of techniques we are able to help you to understand how your product interacts with the skin. This type of analysis can be applied to cover a complete range of applications and compounds of interest including the following:

• FTIR-ATR analysis of skin to determine presence of specific organic species
• Biopsy analysis of scalp tissue with investigations by TEM
• Tape stripping of skin to determine active levels e.g aluminium or silver
• Fluoride, Zinc determine in a variety of substrates
• Deposition studies using XRF

Skin Electron Microscopy Services

The state of the art techniques that are provided by Intertek include SEM/EDX elemental analysis which can also be used to show the deposition of elements such as silicone from a hair conditioner product on to the hair or scalp. Biological TEM can be applied to skin tissue samples to study morphological change tracking and depostiion studies. This service is availble to GLP and was launched in response to a range of pharmaceutical customers who had found this difficult to source.

In vitro skin toxicity testing

Assessment of the dermal absorption and percutaneous penetration behaviour are essential components of the risk assessment for chemicals, cosmetics, personal care and home care products that may make contact with the skin. Furthermore, in compliance with the REACH directive (EC 1907/2006) and the 7th Amendment to the EU Cosmetics Directive (Article 4a) it is necessary for developers and manufacturers to employ in vitro methods for this safety testing. Intertek uses in vitro skin models to study the potential cytotoxic effects of skin applied treatments or chemicals. The models, based on human reconstructed epidermis which approximates the barrier of normal human skin. Topical application of a substance mimics the route of human exposure and ECVAM validated methods for both skin irritancy and corrosion can be carried out.

Skin Forum

Intertek representatives will be presenting our technical capabilities at the Skin Forum, hosted by the Academy of Pharmaceutical Sciences (London, June 25th 27th ). Please call or email for further information. The annual Skin Forum brings together internationally recognized experts to discuss topics relevant to the physiochemical and biological properties of human skin.