TABLE 2.
Population PK parameters obtained from the PK model for plasma and tissue concentrations of penicillin for cattle
| Parameter | Description | Value (RSE [%])a |
Bootstrap value | CI |
||
|---|---|---|---|---|---|---|
| Population mean | IIV | 2.5% | 97.5% | |||
| V1 (liter) | Volume of distribution for the central compartment | 3.45 (12) | 9.59 (23) | 3.44 | 3.39 | 3.47 |
| V2 (liter) | Volume of distribution for the peripheral compartment 1 | 20.8 (14) | 0.89 (22) | 21.9 | 21.6 | 22.2 |
| V3 (liter) | Volume of distribution for the peripheral compartment 2 | 30.3 (13) | 0.45 (15) | 30.4 | 29.9 | 30.7 |
| VL (liter) | Volume of distribution for the liver compartment | 11.2 (29) | 2.76 (31) | 11.4 | 11.3 | 11.5 |
| VK (liter) | Volume of distribution for the kidney compartment | 12.5 (25) | 2.91 (13) | 13.1 | 12.3 | 13.3 |
| CL1 (liters/h) | Central clearance | 105 (32) | 0.89 (23) | 105 | 104 | 106 |
| CL2 (liters/h) | Clearance between the central and the peripheral 1 compartment | 24.8 (13) | 0.37 (11) | 24.8 | 24.5 | 25.1 |
| CL3 (liters/h) | Clearance between the central and the peripheral compartment 2 | 9.65 (23) | NE (NA) | 9.75 | 9.63 | 9.86 |
| CLL (liters/h) | Clearance between the central and the liver compartment | 21.5 (37) | NE (NA) | 21.7 | 21.4 | 21.8 |
| CLK (liters/h) | Clearance between the central and the kidney compartment | 21.5 (24) | 4.04 (12) | 20.7 | 20.5 | 21.1 |
| Kim1 (liters/h) | Absorption rate constant after intramuscular (i.m.) injection of penicillin sodium | 0.31 (14) | 0.05 (5.7) | 0.33 | 0.31 | 0.35 |
| Kim2 (liters/h) | Absorption rate constant after intramuscular (i.m.) injection of procaine penicillin | 0.22 (17) | 0.35 (17) | 0.21 | 0.20 | 0.22 |
| Ksc (liters/h) | Absorption rate constant after subcutaneous (s.c.) injection of procaine penicillin | 0.56 (15) | NE (NA) | 0.55 | 0.54 | 0.56 |
| Kpo (liters/h) | Absorption rate constant after oral administration (p.o.) of procaine penicillin | 0.38 (11) | NE (NA) | 0.38 | 0.37 | 0.39 |
| Fim1 (%) | Bioavailability of penicillin after i.m. injection of penicillin sodium | 80.1 (7.3) | 1.24 (16) | 79.8 | 79.1 | 80.5 |
| Fim2 (%) | Bioavailability of penicillin after i.m. injection of procaine penicillin | 91.3 (19) | 1.84 (22) | 91.0 | 90.1 | 91.8 |
| Fsc (%) | Bioavailability of penicillin after s.c. injection of procaine penicillin | 75.2 (12) | 2.31 (21) | 74.7 | 74.1 | 75.3 |
| Fpo (%) | Bioavailability of penicillin after p.o. injection of procaine penicillin | 42.4 (14) | 2.01 (15) | 42.6 | 42.1 | 43.1 |
| Covariate factors | ||||||
| θ1 | Estimated covariate factor of wt on V3 | −0.005 | −0.005 | −0.0051 | −0.0049 | |
| θ2 | Estimated covariate factor of wt on CLL | 0.008 | 0.008 | 0.0078 | 0.0082 | |
| θ3 | Estimated covariate factor of age on V1 | −0.011 | −0.011 | −0.011 | −0.012 | |
| Residual errors (%) | 23 | |||||
a
RSE, relative standard error; NE, not estimated; NA, not applicable.