Peppermint (Mentha x piperita) is a member of the mint family and one of the oldest cultivated medicinal plants. Peppermint extract is an extremely popular ingredient in many cosmetic products, mainly due to its numerous positive effects on the skin. Its essential oil extracted from both dried and fresh leaves is commonly used. The composition of peppermint is very complex and can be influenced by various factors, the most important of which are climate, maturity of the plant, harvesting time, growing conditions, extraction methods. Like many plants, peppermint can cause undesirable effects, mainly in the form of skin irritation and hypersensitivity reactions. However, it is important to ensure that its use does not cause a risk to human health. The safety assessment of cosmetic products is crucial to ensure that consumers are protected from possible adverse effects. Therefore, in this thesis, a Toxicological Threshold Concern (TTC) approach was used to assess the safety, based on the classification of compounds into Cramer toxicity classes. Each class has a threshold value that represents the maximum permissible exposure to a particular compound. Using the literature, we studied the composition of the extract, then calculated the molecular mass for each component and predicted the values of logP (water to octanol ratio) and logS, based on which we were able to estimate the potential extent of dermal absorption of each compound, and thus its systemic exposure. For some compounds in peppermint extract, we were also able to find NOAEL values in the literature, from which we calculated daily safe doses, which were for all compounds in the extract well above the values determined by the TTC approach, as well as their calculated systemic exposures. Based on all this information and calculations, we concluded that peppermint extract is safe for use in cosmetic products.
|