35
In urine, examples of regression equations for buprenorphine in the
range 5-100 ng/ml were, C _+ 1.59 ng/ml = (68.9 +_ 1.11) PHR 13.93 +_
1.12, r = 0.9991; C + 0.89 ng/ml = (113 + 1.89) PHR 6.8 + 0.851, r =
0.9993; C + 2.02 ng/ml = (66.5 + 1.26) PHR 7.31 + 1.17, r = 0.9977.
Examples of regression equations for buprenorphine conjugate (M) in
plasma in the range 10-50 ng/ml were, C + 2 ng/ml = (57.02 _+ 2.13) PHR +
4.9 _+ 1.211, r = 0.9958; range 60-100 ng/ml; C +_ 1.12 ng/ml = (39.57 +_
1.247) PHR + 22.2 +_ 1.83, r = 0.9985; range 5-100 ng/ml, C +_ 1.4 ng/ml =
(73.8 j+ 0.99) PHR 2.46 +_ 0.8, r = 0.9991; range 10-90 ng/ml; C +_ 1.3
ng/ml = (50.14 + 0.8) PHR 1.51 + 0.92, r = 0.9991.
Examples of regression equations for buprenorphine conjugate (M) in
urine in the range 10-200 ng/ml were, C +_ 1.8 ng/ml = (82 _+ 0.621) PHR +
0.72 +_ 0.82, r = 0.9997; range 10-120 ng/ml, C + 2.6 ng/ml = (92.99 +_
2.4) PHR 27 + 2.5, r = 0.998; C + 1.81 ng/ml = (162 + 2.9) PAR 13.19
+_ 1.5, r = 0.9991, where PAR = peak area ratio; range 10-100 ng/ml, C +_
2 ng/ml = (66.5 _+ 1.26) PHR 7.31 +_ 1.17, r = 0.9977. An example of
regression equation for buprenorphine conjugate (M) in bile in the range
10-200 ng/ml was: C _+ 6 ng/ml = (102 _+ 2.7) PHR 0.53 +_ 2.63, r =
0.9956.
Twice the standard error of estimate of buprenorphine and the
metabolite concentrations (ng/ml) on peak height ratio ranged from 1-5
ng/ml (Table 1), indicative of the sensitivity of the fluorimetric assay
of buprenorphine and its metabolite in biological fluids.
Plasma Pharmacokinetics and Volumes of Distribution. The plasma
concentration-time profile of buprenorphine could be fitted to a sum of
three exponentials (Eq. 2, Figs. 4-9). There may not be an unique linear
sum of three exponentials Cp^ (estimated plasm concentration) that