Page 67 - Interactive Theoritical Notes of Bioharmaceutics and pharamcokinetics.docx compressed

PharmD clinical pharmacy program Level 3, Semester 2 Biopharmaceutics & Pharmacokinetics (PT608(

 A practical steady-state concentration has been reached when the plasma

concentration of a drug in the blood represents 95% or greater of the Css. It takes

(4.32 t½) to reach practical steady-state concentration.

Rate of drug input= rate of drug output

(infusion rate) = (elimination rate)

R = kDB

 Integration and substitution

(DB = Cp Vd)

 = ( − − )

-kt
 At infinite time t = ∞, e approaches zero,

 =

 The body clearance

(Cl = VdK)

 = =

For the infusion rate: R = Cl x Css

For loading dose: DL = Vd x Css =

Instantaneous and continuous steady state

Notes

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