Validated LC-MS/MS method for the determination of copanlisib in mouse dried blood spots

Copanlisib is a dual PI3K-δ inhibitor, used in follicular lymphoma treatment. In this research, we report a validated LC-MS/MS method for quantifying copanlisib from a mouse dried blood spot (DBS). We validated the method in line with the guidelines of the US Food and Drug Administration. The liquid-liquid extraction technique was used to extract copanlisib from the DBS discs. We used an Atlantis dC₁₈ column and isocratic mobile phase for the chromatographic separation of copanlisib and the internal standard (idelalisib). The flow was 0.90 ml/min. Under the optimized chromatographic conditions, the retentions of copanlisib and the internal standard were 0.98 and 0.93 min, respectively. Each injection total run time was 2.50 min. The MS/MS ion transitions monitored were m/z 481.31 → 128.00 and 416.10 → 176.10 for copanlisib and the internal standard (IS) idelalisib, respectively. We have used a broad calibration range (1.01-4,797 ng/ml) with a determination coefficient (r² ) of 0.997. All of the evaluated parameters met the acceptance criteria. Hematocrit did not influence the DBS copanlisib concentrations. We have used the validated method to derive the intravenous pharmacokinetic parameters by quantifying copanlisib in mouse plasma.