Photostability Testing Guidelines of New Drug Substances

The ICH Q1B guideline is the harmonized effort to standardize photostability testing on new pharmaceutical drug substances and drug products.

Photostability Guidelines

Testing is carried out on a single batch of material selected. Whether studies should be repeated depends on the photostability characteristics determined at the time of initial filing and the type of variation and/or change made. The guideline primarily addresses the generation of photostability information for submission in Registration Applications for new molecular entities and associated drug products. It does not cover the photostability of drugs after administration (i.e. under conditions of use) and those applications not covered by the Parent Guideline.

UV light Graph created at completion of photostability study
UV light graph created at completion of photostability study
Visible light Graph created at completion of photostability study
Visible light graph created at completion of photostability study

 

Procedure

The intrinsic photostability characteristics of new drug substances and products should be evaluated to demonstrate that, as appropriate, light exposure does not result in unacceptable change. For confirmatory studies, samples should be exposed to light providing an overall illumination of not less than 1.2 million lux hours and an integrated near ultraviolet energy of not less than 200 watt hours/square meter.

  • Samples are exposed side-by-side to ensure the specified light exposure
  • Samples are exposed for the appropriate duration of time
  • Monitoring is completed using calibrated radiometers/lux meters
  • Dark controls, if specified (wrapped in Alufoil,) placed alongside the authentic sample to evaluate contribution of thermally induced change.
  • Reports are generated confirming light exposure over time (see image).

For more information please don’t hesitate to contact Q1 Scientific.