TABLE 2

Initial estimates for tissue partitioning coefficients for morphine and MG and estimated according to the method of Rodgers and Rowland (2006, 2007) for PBPK modeling

ParameterMorphine
Initial EstimateTMSFM
Blood unbound fraction (fB)0.654a0.6540.654
0.634b
Partition coefficient for rapidly perfused tissue (KRP)3.69c2.05 (47.2)d5.03 (38.8)d
Partition coefficient for poorly perfused tissue (KPP)2.37c1.03 (42.8)d1.16 (60.3)d
Partition coefficient for adipose tissue (KAD)1.08c0.796 (23.9)d1.63 (20.9)d
  • a Method of Doherty et al. (2006), using fP = 0.89 and CB/CP of 1.08 [fB = fP/(CB/CP)].

  • b Method of Mistry and Houston (1987), using fP = 0.85; CB/CP = 1.34.

  • c Calculated according to the method of Rodgers and Rowland (2006, 2007).

  • d Fitted estimates, with percent CV within parentheses.