BACKGROUND The presence of impurities in some drugs may compromise the safety and efficacy of the patient's treatment. Therefore, establishing of the biological safety of the impurities is essential. Diabetic patients are predisposed to tissue damage due to an increased oxidative stress process; and drug impurities may contribute to these toxic effects. In this context, the aim of this work was to study the toxicity, in 3 T3 cells, of the antidiabetic agents sitagliptin, vildagliptin, and their two main impurities of synthesis (S1 and S2; V1 and V2, respectively). METHODS MTT reduction and neutral red uptake assays were performed in cytotoxicity tests. In addition, DNA damage (measured by comet assay), intracellular free radicals (by DCF), NO production, and mitochondrial membrane potential (ΔψM) were evaluated. RESULTS Cytotoxicity was observed for impurity V2. Free radicals generation was found at 1000 μM of sitagliptin and 10 μM of both vildagliptin impurities (V1 and V2). A decrease in NO production was observed for all vildagliptin concentrations. No alterations were observed in ΔψM or DNA damage at the tested concentrations. CONCLUSIONS This study demonstrated that the presence of impurities might increase the cytotoxicity and oxidative stress of the pharmaceutical formulations at the concentrations studied.

中文翻译：

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两种脂肪素及其合成主要杂质的体外毒性评价。

背景技术一些药物中杂质的存在可能损害患者治疗的安全性和有效性。因此，建立杂质的生物安全性至关重要。糖尿病患者由于增加的氧化应激过程而容易受到组织损伤。和药物杂质可能会导致这些毒性作用。在这种情况下，这项工作的目的是研究抗糖尿病药西他列汀，维格列汀及其两种主要合成杂质（分别为S1和S2； V1和V2）在3个T3细胞中的毒性。方法在细胞毒性试验中进行MTT降低和中性红吸收试验。此外，还评估了DNA损伤（通过彗星测定法测量），细胞内自由基（通过DCF），NO产生和线粒体膜电位（ΔψM）。结果观察到杂质V2的细胞毒性。在西他列汀1000μM和维他列汀两种杂质（V1和V2）的10μM处发现了自由基的产生。在所有维格列汀浓度下均观察到NO生成量减少。在测试浓度下未观察到ΔψM或DNA损伤的变化。结论这项研究表明，在所研究的浓度下，杂质的存在可能会增加药物制剂的细胞毒性和氧化应激。