Talaporfin Sodium Pharmacokinetics in Skin Tissues for Skin Photosensitivity Risk Assessment

We studied the concentration change of talaporfin sodium in human skin by in silico pharmacokinetics model for quantitative evaluation of skin photosensitivity risk. Talaporfin sodium is clinically applied with light shading in a room of less than 500 lux for two weeks. Although it doesn't prescribe a hospitalization, basically two weeks of hospitalizations are conducted. In order to reduce patient burden and medical costs, it is necessary to obtain the scientific evidence on the safety of skin photosensitivity. We performed a clinical study of the talaporfin sodium fluorescence measurement in skin tissue using our developed transdermal fluorescence measurement system. This clinical study was conducted at Tokyo Medical University Hospital and Nippon Medical School Hospital. Talaporfin sodium concentration change was evaluated by measuring talaporfin sodium fluorescence using a blue LED (wavelength 409 16 nm) for excitation of the Soret band absorbance peak. We investigated the time range where the skin photosensitivity risk is high after administration, by using an in silico pharmacokinetics model to predict the continuous photosensitizer concentration change in skin tissue.