P30-2 Examination of improvement mechanism by minocycline application for skin disorders caused by afatinib

Abstract

We have clarified that minocycline petrolatum ointment prevents and repairs skin disorders caused by afatinib in mice, but its mechanism of action is unknown. In order to make this minocycline ointment usable in clinical practice, we proposed to dilute the already commercially available dental Perioclin ointment (containing minocycline) with petrolatum and use it, and its skin disorder improving effect and stability as a preparation. (1) After continuous oral administration of afatinib (20 mg / kg BW) to ddy male mice, the expression levels of EGFR and TNFa in the skin of mice coated with minocycline (0.03 mg / 0.1 g) were measured by the ELISA method. (2) The effect of minocycline ointment obtained by diluting Perioclin ointment with petrolatum was compared with that of minocycline vaseline ointment, and the minocycline content was measured using HPLC. (1) Both epidermal EGFR and TNFa levels were significantly decreased in the afatinib-administered group and recovered to normal levels by application of minocycline. (2) The minocycline ointment prepared by diluting the Perioclin ointment was as stable as or more stable than the conventional minocycline vaseline ointment, and improved the dryness of the skin by afatinib. It was suggested that minocycline may repair skin tissue by recovering epidermal EGFR level and TNFa level in response to afatinib-induced skin damage. Sano et al. BMC Cancer (2020) 20:279.