Metronidazole and exposure to light

Hello everyone,
After some reading, I discovered that after being added to our aquariums, metronidazole denatures ( I believe that is the correct term) within a matter of some hours due to light exposure. This led to me wonder whether the same thing happens, that is, the substance being rendered ineffective, if the container the metronidazole is contained in is exposed to sunlight. I have around 100g of the stuff that I foolishly didn't store in a light proof container and I just wanted to know if it's as good as dust now that it's been exposed to sunlight.

Thank you all in advance :)

I'm sure it didn't do it a world of good, but the only way to know is try is and see if the fish in question improve. It's a very safe med, you could even double dose it without doing any harm.

Thank you for the insight, I just got 2 new wild discus recently and they're currently in quarantine, want to give them a set of meds and let them be on their own for a while before introducing them to the main aquarium. I guess I'll have to use it and see!

The powder along the outside of the container that is exposed to light will probably be inactive. The powder toward the center of the container away from the light, should still be active.