Bioequivalence and Bioavailability Forum

Dear Kaushik!

❝ what is the max time limit if samples are exposed to sunlight for typical light sensitive drugs ?

What is the “typical” light sensitive drug?

❝ situations like power failures were monochromatic lights doesnt work then can v take the samples under normal light and raise a deviation of that specific protocol?

I think just filing a protocol deviation would not satisfy inspectors. Generally sensitivity to light depends not only on the drug itself, but also on the solvent, the pH, etc. Even if the drug is susceptible to degradation in stock solutions it might be well protected in plasma. In short: It depends on the procedure(s). We once had a method for nifedipine which employed only centrifugation, transfer to brown autosampler vials and on-column switching. Didn’t make any difference whether this procedure was done in monochromatic (Na), fluorescent, or daylight. But: We validated it!

❝ how to overcome such situations?

1. If you expect power outages, check whether any steps of the method are critical (cave: that’s a partial validation). Document and include in the SOP which steps would trigger a stop. Better to loose one day of analysis than to have fruitless arguments later on.
   Consider buying: car battery, power transformer, a.c. converter, insulated cables.
   
2. If you have not investigated a potential effect yet and a power outage occurs, stop the procedure. Perform #1.
   
3. Not recommended: Analysis went on as if nothing happened. File a deviation. Perform #1. If none of the steps affect the results, include results of your investigation in the analytical report. If anything* affects the outcome, repeat the batch.

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• To be precise: Any critical step performed during the power outage. Example: If the drug is sensitive in stock solutions but not in sample processing, spiking of the CC and QC samples is critical.