Patch Test for Cosmetics – following FDA standards | Confirm the safety of your product through compatibility Clinical Trials.

For the free marketing of personal care, cosmetics, sanitizing and health/correlated products, clinical trials might be necessary, in order to assure the in-use safety. Since they get in touch with the skin, nails, hair, teeth and mucous as gums and intimate area, these products might cause clinical signs, discomfort sensations or event systemic effects when any ingredients of the formula enter into the circulatory blood flow, regardless the application route.

Possible risks to the health and consumer free access to buy those products make it compulsory for the best forms of consumption and the effects of improper or accidental use to be clarified and properly described on the packaging in the market, as it can be seen in the items related to the use directions, warning, how to proceed in case of accidental contact with other areas, storage guidelines, among others.

That way, investigational methods were developed by using study subjects, with the aim of assessing the safety of products under maximized or semi-maximized conditions and they are known as Compatibility Studies.

The checking the safety of a product under normal use conditions is carried through Acceptance Studies developed after product analysis in Patch Tests.

Compatibility Studies allows the investigation of potential irritation or sensitization (allergy) mechanisms, through the appearance of clinical signs or discomfort sensations that might be provoked by the tested formula after contact with human skin, all studies are supervised by dermatologists.

Discomfort sensations are symptoms reported by the subject to the study development team such as burning sensation, pain, pruritus, among others, with transient or long-lasting duration, restricted or not to the application area and that might indicate an irritation or sensitization.

Clinical signs area phenomena visible on the subject’s skin such as erythema (redness), edema (swelling area), vesicles (blisters), hyperpigmentation, among others, with extension and duration are also observed by the technical staff and assessed by a dermatologist. The clinical signs are scored by using the scale defined by the Contact Dermatitis Research Group.

Patch Test represent the first assessment with humans of the finished product. These studies are carried under maximized or semi-maximized conditions, i.e. more intense situations when compared to normal use conditions aimed for the product. For increasing the chances of clinical signs and discomfort sensation occurrence, these investigations have a predictive value, which does not mean that the tested product and assessed as being safe is completely exempt from promoting any reactions in the population or target population.

The study methodologies of Compatibility can consist in the single application or repeated applications of the product with occlusive or semi-occlusive patches (patch test) or in open models (open tests); the site and application mode, number of application and exposure period of the product on the skin can be changed. The study models using patches are known as compatibility studies in patch, the use of occlusive patches promotes a superior maximization as it avoids skin and product exchanges with the external environment when compared to the use of semi-occlusive patches.

Several categories of products can be tested and products primarily irritating should be tested after dilution so false positive results are not generated.