Kenneth S. Albert

Pharmacokinetics of ibuprofen in man. I. Free and total area/dose relationships

Ibuprofen kinetics were studied in 15 subjects after four oral doses. Plasma levels of both total and free ibuprofen were measured for 12 hr, and urine was collected for 48 hr after the doses. All subjects showed a nonlinear relationship between dose and total ibuprofen plasma AUC. Free ibuprofen plasma AUC, however, was linearly related to the dose, suggesting that oral clearance based on free drug was dose independent. Urinary recovery data indicated that efficiency of absorption was dose independent.

Pharmacokinetics of orally administered acetaminophen in man

Average and individual sets of plasma concentration-time data for acetaminophen following two oral treatments were simultaneously fitted to the integrated equation describing the two-compartment open model with first-order absorption and lag time. The nonlinear least-squares program NONLIN and an IBM 360/67 digital computer were employed to estimate nine parameters (kA, kB, CA0, CB0, k12, k21, kel,

Bioavailability Studies of Acetaminophen and Nitrofurantoin

t_{0_A }

Pharmacokinetics of ibuprofen in man IV: Absorption and disposition

and

Rectal and oral absorption of methylprednisolone acetate.

t_{0_B }

Determination of Adrenal Response After Oral Administration of Multiple Doses of Methylprednisolone

).When the mean plasma concentrations were weighted according to the inverse of their variances, the parameter estimates more accurately reflected those for individual subjects in the disposition portion of the model. Depending on the relative magnitudes of the disposition rate constants (k12, k21,and kel),the one-compartment open model can be used to predict equilibrium-state plasma levels even though the drug is really “two compartment.” Equations are presented which show when the one-compartment approximation is justified. Equations are also presented for calculation of loading doses for multiple dose regimens of any drug obeying the two-compartment open model and the equations are applied to acetaminophen.