Green Coffea arabica L. seed oil influences the stability and protective effects of topical formulations

• GCO formulations had a positive influence in the sun protection factor.
• GCO formulations were able to reduce transepidermal water loss.
• Only high concentrations of GCO presented desirable protective effects.

Green Coffea arabica L. seed oil (GCO) has been used as an active ingredient in many skin care products, due to its properties as an emollient, improver of skin hydration and absorbent of UVB radiation. However, to obtain a stable, effective and pleasant formulation containing variable amounts of GCO it is necessary to know specific chemical characteristics of the combined ingredients. Thus, this study evaluated rheological behavior, presence of liquid crystals (LCs) and skin protective effects of GCO-containing formulations aiming to correlate these parameters with GCO concentrations by using a principal component analysis (PCA). Formulations containing GCO or not (0–15%) were submitted to physical stability assays by determinations of rheological behavior after 90 days storage, detection of LCs by polarized light microscopy and in vitro determination of the sun protection factor (SPF). In vivo protective effects in mice were evaluated with biophysical techniques and histological analysis. Data were correlated using PCA. Despite the low SPF values, GCO addition to formulations resulted in significant and proportional increases of these values. It is concluded that formulation stability and skin protective properties are influenced by GCO but desirable effects are only possible when GCO is present in high concentrations.