Photocatalytic degradation of water insoluble (warfarin and norethindrone) and more soluble (atomoxetine) medications were evaluated to determine if it is a viable method for disposal of unused medications. Unused prescription drugs in the household are often disposed of in the garbage or down the sewer, which can lead negative impacts on the environment. Leaving them undisposed leads to the potential for misuse and abuse. Photocatalytic degradation of pharmaceuticals in ultraviolet (UV) light is a promising alternative for proper disposal. Warfarin (4-hydroxy-3-(3-oxo-1-phenylbutyl)chromen-2-one), norethindrone (8R,9S,10R,13S,14S,17R)-17-ethynyl-17-hydroxy-13-methyl-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-3-one), and atomoxetine ((3R)-N-methyl-3-(2-methylphenoxy)-3-phenylpropan-1-amine) were evaluated. All degradation studies were performed by adding 100 ppm of the pure compound to water, exposing to UV light (254 nm), and analyzing samples over time to determine remaining concentration of compound by HPLC. For all studies, control samples were also prepared, were not exposed to UV light and were analyzed at the same time as UV-treated samples. Samples were exposed to UV light and analyzed until no compound was detected by HPLC. For warfarin, iron oxide from several different acid mine drainage locations was added to determine if it would aid in the degradation process when exposed to UV light. Warfarin degraded very slowly (many days), but with iron oxide, showed slightly improved degradation rates compared to samples with no iron oxide. Degradation rate of norethindrone is being evaluated but appears to degrade faster than warfarin based on initial results. Atomoxetine is also being evaluated and has a much faster degradation rate (several hours) than warfarin or norethindrone. UV-treated samples are being analyzed on Microtox<sup>®</sup> and compared with results of control samples to determine if toxicity to bioluminescent bacteria changes after UV treatment. Initial studies on warfarin and atomoxetine samples show an increase in toxicity as the degradation process proceeds. Studies are continuing and rate constants are being determined.

Photocatalytic degradation of warfarin, atomoxetine, and norethindrone

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