Eylem Funda GÖKTAŞ, Erol KABİL, Ertuğrul GÜNEŞ, Serol KORKMAZ, Tuba Asena KADIOĞLU, Ayşen KURT GÜCÜ

Uluslararası tarama limiti olan bazı ilaçların at kanında LC-MS/MS ile tayini ve stabilitesi

Doping kontrolü amacıyla uluslararası tarama limiti kapsamında olan bazı terapötik maddelerin at kanında valide bir metotla LC-MS/MS cihazı kullanılarak stabilitesi araştırılmıştır. Tam kan örneklerinde ortofosforik asitle kimyasal hidroliz sonrasında bir WAX kartuş kullanılarak otomatik katı faz ekstaksiyonuyla ekstrakte edilmiştir. Etken maddelerinin stabilite testi, çalışma çözeltisinde ve matriks içerisinde +4°C, -20°C, +20°C karanlıkta ve +20°C gün ışığında 1, 2, 3 ve 4 hafta için eşzamanlı olarak çalışılmıştır. Kısa zamanlı stabilite çalışması +55°C’de 6 saat saklamanın etkisini kapsayacak şekilde araştırılmıştır. Yapılan tekrarlı analizler ANOVA ile istatistiksel olarak değerlendirilmiştir. Çalışma çözeltisindeki tüm maddeler -20°C ve 4°C'de stabildi. Işıkta ve karanlıkta yüksek sıcaklık, dört hafta sonunda ve kısa süreli çalışmada kan matriksindeki maddelerin bozunmasına neden olmuştur (P< 0.05). Sonuç olarak, bu uluslararası tarama limitli maddeler sıcaklık ve zamana bağlı olarak kan matriksinde stabil olmayabilirken, çalışma çözeltisinde farklı sıcaklıklarda dört hafta boyunca çoğunlukla stabildir.

Determination and stability of some international screening limited drugs in equine blood by LC-MS/MS

Stability of some international screening limited therapeutic substances for doping control in equine blood has been investigated with a validated method by using LC-MS/MS after chemical hydrolysis with orthophosphoric acid. Whole blood samples were extracted with a WAX cartridge on auto-SPE. Stability test of the drug substances performed at the same time in working solution and matrix at +4°C, -20°C, +20°C in dark and +20°C in light conditions for 1, 2, 3 and 4 weeks. For short-time stability, the effects of 6 h storage at +55°C was also investigated. Repeated data were statistically analyzed with ANOVA. All substances in working solution were stable at -20°C and +4°C. In the blood matrix, higher temperatures (+20°C) in light and dark caused degradation of substances at the end of four weeks and short-term study (P< 0.05). In conclusion, these international screening limited substances in blood matrix could be unstable related to temperature and storage time, although in working solution they could be mostly stable in various temperatures for four weeks.

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