Evaluation of glucuronide metabolite stability in dried blood spots

Background: Stabilization of phase II metabolites is an important consideration during bioanalytical method development, method validation and sample analysis. Generic approaches to stabilize these metabolites during storage in liquid-based matrices include pH adjustment of samples prior to storage and/or temperature control; although a variety of other compound-specific stabilization techniques exist. Dried blood spot (DBS) technology is becoming a popular alternative to liquid matrix sampling in many preclinical and clinical applications. However, concerns remain regarding the stability of metabolites stored under ambient conditions using DBS. Results: Experimental data have shown that, under ambient storage conditions, the stability of the glucuronides investigated herein stored as DBS is equivalent to that of liquid samples stored at -80 degrees C. Conclusion: The decision to employ DBS technology for a given study needs to be considered on a case-by-case basis with an understanding of compound-specific metabolism characteristics and clinical study design.