Chapter 22 – Photosafety Assessment

This chapter reviews the current state of photosafety testing in preclinical drug development, a topic that is important in preclinical drug development but is unfamiliar to many. The regulatory status of this testing, including the historical development of the regulations, and basic concepts of dosimetry, light sources, and spectral absorption are described. The chapter then describes the rational approaches to photosafety assessment including in vitro and in vivo methodologies in specific models relevant to photosafety evaluations along with the methods used to identify in vitro signals and in vivo cutaneous and ocular phototoxicity in these models. The development of a rational photosafety strategy is also described.