Table II.

Pharmacokinetic Absorption and Disposition Parameters of Total and Free Prednisolone

Parameter	White Males	Black Males	White Females	Black Females	p-Value
					Gender	Race	Gender × Race
Total prednisolone
Absorption
ka (h−1)	5.62 ± 5.78	9.71 ± 8.13	4.80 ± 4.44	2.98 ± 1.86	NS	NS	NS
tlag (h)	0.283 ± 0.0861	0.294 ± 0.0341	0.263 ± 0.139	0.243 ± 0.0963	NS	NS	NS
Disposition
Vc/F (L)	44.8 ± 12.1	45.5 ± 15.2	29.1 ± 8.85	42.2 ± 8.46	< 0.05	NS	NS
Vc/F/TBW (L/kg)	0.590 ± 0.196	0.613 ± 0.169	0.453 ± 0.136	0.586 ± 0.101	NS	NS	NS
CL/F (L/h)	13.5 ± 2.91	12.6 ± 2.03	11.8 ± 2.16	11.7 ± 1.89	NS	NS	NS
CL/F/TBW (L/h/kg)	0.178 ± 0.05	0.172 ± 0.0181	0.181 ± 0.0266	0.165 ± 0.0399	NS	NS	NS
t1/2 (h)	2.33 ± 0.523	2.51 ± 0.813	1.74 ± 0.467	2.54 ± 0.546	NS	< 0.05	NS
AUC (ng•h/ml)	1638 ± 426	1628 ± 239	1544 ± 239	1708 ± 298	NS	NS	NS
Free prednisolone
Absorption
ka (h−1)	6.65 ± 6.26	9.74 ± 6.41	7.94 ± 6.98	4.01 ± 5.07	NS	NS	NS
tlag (h)	0.315 ± 0.108	0.338 ± 0.123	0.343 ± 0.178	0.279 ± 0.0525	NS	NS	NS
Disposition
Vc/F (L)	165 ± 46.6	162 ± 43.0	107 ± 34.0	114 ± 29.4	< 0.01	NS	NS
Vc/F/TBW (L/kg)	2.18 ± 0.745	2.183 ± 0.357	1.65 ± 0.462	1.58 ± 0.321	< 0.01	NS	NS
CL/F (L/h)	59.4 ± 14.9	57.6 ± 13.8	42.1 ± 9.59	39.8 ± 6.40	< 0.01	NS	NS
CL/F/TBW (L/h/kg)	0.788 ± 0.265	0.778 ± 0.143	0.644 ± 0.108	0.554 ± 0.093	< 0.01	NS	NS
t1/2 (h)	1.92 ± 0.264	2.01 ± 0.538	1.76 ± 0.264	2.01 ± 0.466	NS	NS	NS
AUC (ng•h/ml)	375 ± 111	364 ± 65.6	434 ± 68.5	497 ± 84.2	< 0.01	NS	NS

NS, not significant (p > 0.05). Data are mean values ± SD (n = 8/group). k_a, first-order absorption rate constant; t_lag, time lag in absorption; V_c/F, apparent volume of the central compartment; TBW, total body weight; CL/F, apparent systemic clearance; t_1/2, half-life; AUC, area under the prednisolone concentration versus time curve.