Plasma (TP2)
The levels of total radioactivity in the 0–8 h and 10–12 h plasma pools were 1492 DPM/g and 121 DPM/g, respectively, corresponding to 268 ng daprodustat equivalents/g and 22 ng daprodustat equivalents/g. Overall recovery of radioactivity following sample preparation was 85 and 69% for the 0–8 h and 10–12 h pools, respectively. The low recovery in the 10–12 h sample was attributed to a very low initial level of radioactivity, as quantified by LSC (rather than by AMS).Quantitative results of radioactive components in pooled plasma samples are given in Table Quantification of the radioactive components in plasma, urine, and fecal extracts following a single oral dose of [Abbreviations: DPM, disintegrations per minute; LLQ, lower limit of quantification; ND, not detected.% radioactivity recovered under each integrated radio peak.ng equivalents of daprodustat per g of plasma under each integrated radio peak.Mean % administered dose recovered under each integrated radio peak.Absolute quantification of drug‐related components is not possible due to the qualitative nature of the bile string sampling and extraction procedure.The estimation for M2 and M33 was 8.1% and 2.3% respectively, based on extrapolation from validated bioanalytical data for M2, M3, M4, and M5.Low value due to limited radioactivity in the sample for HPLC analysis (ca. 168 DPM on column).Reconstructed HPLC‐radiochromatograms of pooled plasma extracts following a single oral dose of [In the 10–12 h pool, only metabolite peaks of coeluted M2 and M33, M3, and M13 were quantifiable, each representing 14%, 12%, and 16% of plasma radioactivity, respectively. Peaks M5, M6, M14, M15, and P were detected at below the LLQ.Overall, quantifiable peaks constituted 93% and 50% of plasma radioactivity in the 0–8 h and 10–12 h pools, respectively.