ABSTRACT
INTRODUCTION The photostability of active pharmaceutical ingredients (API) and drug products (DP) may impact shelf life, handling, packaging, and even photosafety of the product (e.g., phototoxicity and photogenotoxicity). Hence, photostress testing is an important component of the drug development process and it is important to understand the intrinsic photoreactivity of the API early in development. A photo-unstable API may be
• problematic to isolate; • diffi cult to formulate under typical conditions in a DP manufacturing suite; • complex to pack for shipping to the clinic/pharmacy; • diffi cult to dose (e.g., if it is administered topically or by infusion); • diffi cult to analyze if unstable in a typically lit laboratory (vials may need to be wrapped in
aluminum foil or otherwise protected from light); • an indicator for photosafety concerns that may require further investigation.
