Toxicity of commercial and pure forms of three nonsteroidal anti-inflammatory drugs in Xenopus laevis embryos before and after ozonation.

In this study, the toxic and teratogenic effects of three commercial drugs and their active ingredients on Xenopus laevis embryos before and after ozonation were evaluated using the Frog Embryos Teratogenesis Assay-Xenopus (FETAX). First, the median lethal concentration (LC₅₀) and, if data were available, the median effective concentration, teratogenic index and minimum growth inhibitory concentration were determined for each drug substance without ozonation. Then, the active substance amounts of three selected nominal concentrations (LC₅₀/2, LC₅₀, and LC₅₀×2) of each test substance before ozonation were measured by HPLC analysis and the toxicity of these substances was evaluated after 2, 3, 4, and 5 h of ozonation. In addition, degradation products that may occur during ozonation were evaluated by LC-MS analysis. The 96-h LC₅₀s of Dolphin-diflunisal, Dichloron-diclofenac sodium, and Apranax-naproxen drug-active substance pairs were determined to be 22.3 and 11.1, 25.7 and 18.7, and 47.8 mg active substance/L and 45.3 mg/L, respectively. According to the FETAX test results, the Dolphin-diflunisal drug-active ingredient pair did not cause growth retardation in exposed embryos. Dichloron-diclofenac sodium and Apranax-naproxen drug-active ingredient pairs were both teratogenic and growth inhibitory. In the second stage of the study, in which the effectiveness of ozonation in eliminating the toxic effects of drugs is evaluated, it is seen that ozonation is partially successful in eliminating the toxic effects of Dolphin-diflunisal and Dichloron-diclofenac sodium pairs, but insufficient for eliminating the effects of the Apranax-naproxen pair.