227
Figure 76. Semilogarithmic plots of the excretion rate (A BM/A t or
AU/ At) of the buprenorphine conjugate (M, metabolite) plotted against
t-mid, the mid point of the biological fluid collection interval in
accordance with equation 24. a) For 0.5153 mg/kg IV infusion dose of the
metabolite in dog G (Study #14, Table 7), the biliary excretion data was
fitted to a sum of three exponentials. The estimated hybrid rate
constants were 0.0213/min (half-life = 33 min), 0.0079/min (half-life =
88 min) and 0.0021/min (half-life = 330 min). See also Table 7 for the
correspondence of these estimated rate constants to those obtained from
plasma data, b) In the same dog G (Study #14), the urinary excretion
data for the metabolite was fitted to a sum of two exponentials. The
estimated hybrid rate constants were 0.0215/min (half-life = 32 min) and
0.004/min (half-life = 173 min).