Our Drug Substance was Sunbathing at the Beach

In a manner quite contrary to proper scientific method, we managed to degrade our supposedly stable small molecule API while exposing it to three key variables—temperature, humidity and light. Our intention was to quickly confirm robustness but unfortunately, we proved otherwise.

The product in question is a blood pressure medication in early development. After about three weeks in a temperature and humidity controlled light chamber in an open-dish configuration we saw slight yellowing and chromatographically detected a very unexpected bump in what we’ve tentatively identified as nitrosamine impurities. This occurred at 30°C/60%RH and a mere 0.5 million lux-hours of visible light—we were specifically trying to give moderate stress without blasting the material since we were led to believe it was quite hearty, thus we just wanted an objective understanding of its stability.

This particular incident has multiple solutions. We want to hear from you at the discussion below. How can we go about determining which environmental factor was the leading culprit in this degradation so we can avoid performing three studies on this rather precious material?