The effect of K101 Nail Solution on Trichophyton rubrum and Candida albicans growth and ultrastructure.

K101 Nail Solution (trademarks Emtrix(®), Nalox(™), Naloc(™)) is a combination of propylene glycol, urea and lactic acid in a topical formulation for the treatment of nails affected by onychomycosis. The aim of this study was to investigate the Minimal Cidal Concentration (MCC) of K101 Nail Solution against Trichophyton rubrum and Candida albicans as well as the effect of K101 Nail Solution on the micromorphology of these fungi. The MCC of K101 Nail Solution against T. rubrum and C. albicans was 50% after 60-min exposure time. A MCC of 50% for K101 Nail Solution means that K101 Nail Solution diluted with e.g. water to 50% will totally kill the fungi tested. In the scanning electron microscope C. albicans cells, treated with 50% K101 Nail Solution, showed a shrunken surface. T. rubrum cells were severely damaged shown as collapse and degradation of the cells. In the transmission electron microscope most C. albicans cells, treated with 50% K101 Nail Solution exhibited destroyed organelles and many necrotic cells were found. The cell wall was clearly degraded and the contact between the cell wall and the inner membrane was punctured. In T. rubrum most cells were necrotic. Some cells were clearly collapsed and the content in the cytoplasm was degraded shown as small membrane vesicles and many big vacuoles. The cell wall was clearly degraded and the membrane was punctured. In conclusion, this in vitro study documents the efficacy of K101 Nail Solution against T. rubrum and C. albicans.