Chapter 1 Introduction: Photostability Testing of Drugs and Drug Formulations -- Why and How? -- chapter 2 Photophysical and Photochemical Aspects of Drug Stability -- chapter 3 Standardization of Kinetic Studies of Photodegradation Reactions -- chapter 4 Rationalizing the Photochemistry of Drugs -- chapter 5 Technical Requirements and Equipment for Photostability Testing -- chapter 6 Photostability Testing: Design and Interpretation of Tests on New Drug Substances and Dosage Forms -- chapter 7 The Questions Most Frequently Asked -- chapter 8 Inconsistencies and Deficiencies in Current Official Regulations Concerning Photolytic Degradation of Drugs -- chapter 9 Biological Effects of Combinations of Drugs and Light -- chapter 10 In Vitro Screening of the Photoreactivity of Antimalarials: A Test Case -- chapter 11 Screening Dyes, Drugs, and Dietary Supplements for Ocular Phototoxicity -- chapter 12 Photochemical and Photophysical Methods Used in Study of Drug Photoreactivity -- chapter 13 Addressing the Problem of Light Instability during Formulation Development -- chapter 14 Photostability of Parenteral Products -- chapter HÖNLE C Photoactivated Drugs and Drug Formulations -- chapter 16 Formulation Approaches for Improving Solubility and Its Impact on Drug Photostability.