Hines Siddra A, Brandvold Jacob, Mealey Robert H, Call Douglas R, Graça Telmo
Department of Veterinary Microbiology and Pathology, Pullman, WA 99164-7090, USA.
Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164-7090, USA.
Vet Parasitol X. 2020 Feb 7;3:100023. doi: 10.1016/j.vpoa.2020.100023. eCollection 2020 May.
Buparvaquone and parvaquone are hydroxynaphthoquinone compounds commonly used to treat livestock infected with species such as and . In many (sub)tropical regions, chromatic changes in medicines can result from extreme environmental conditions and improper drug storage or handling, raising the possibility of drug degradation and loss of potency. We evaluated the effects of UV light, elevated temperature, and atmospheric air on the stability and potency of both buparvaquone and parvaquone by using a combination of high performance liquid chromatography (HPLC) and a based parasite growth inhibition assay (to measure potency). Aliquots (1 ml; 3 replicates per treatment) of each compound were subjected to a variety of treatments that varied in duration and intensity followed by HPLC and potency assays. Exposure to ambient air for 50 days was correlated with a significant loss of potency for both buparvaquone (4535%, < 0.05) and parvaquone (247%, < 0.05), while elevated temperature (37°C) and UV light exposure (24 h) had no significant impact ( > 0.05). The decrease in potency of both buparvaquone and parvaquone correlated with drug degradation ( = -0.74 and -0.88, respectively) as measured by HPLC. In practice, if there is headspace present in the vial, then ambient air will invariably enter the vial and contribute to degradation of these compounds. Such degradation may contribute to increasing drug resistance, economic losses for farmers, and animal welfare concerns for animals that are treated for Theileria infections.
丁喹酯和萘喹酯是羟基萘醌类化合物，常用于治疗感染泰勒虫属和巴贝斯虫属等物种的家畜。在许多（亚）热带地区，药物的颜色变化可能是由极端环境条件以及药物储存或处理不当导致的，这增加了药物降解和效力丧失的可能性。我们通过结合高效液相色谱法（HPLC）和基于泰勒虫体外寄生虫生长抑制试验（以测量效力），评估了紫外线、高温和大气对丁喹酯和萘喹酯稳定性和效力的影响。将每种化合物的等分试样（1毫升；每个处理3个重复）进行各种持续时间和强度不同的处理，随后进行HPLC和效力测定。暴露于环境空气中50天与丁喹酯（45%至35%，P<0.05）和萘喹酯（24%至7%，P<0.05）的效力显著丧失相关，而高温（37°C）和紫外线照射（24小时）没有显著影响（P>0.05）。通过HPLC测量，丁喹酯和萘喹酯效力的降低与药物降解相关（分别为r=-0.74和-0.88）。在实际应用中，如果小瓶中有顶部空间，那么环境空气将不可避免地进入小瓶并导致这些化合物降解。这种降解可能会导致耐药性增加、农民经济损失以及对感染泰勒虫的动物的动物福利问题。
