Following an IV dose of a drug, the initial plasma concentration and the plasma concentration at 5 hr are reported to be 5.3575 and 1.6879 µg/mL, respectively. Determine the elimination half-life

Answer 1

PowerPoint Presentation a)    Let initial plasma concentration = C_p⁰

C_p⁰   = 5.3575 µg/mL  

When t = 5 hr,

C_p   =  1.6879 µg/mL

Assume first order

t_1/2  = 0.693/k 

From  ln(C_p/ C_p⁰ )=   - kt

Ln(1.6879/5.3575) = - 5hr^-1 x k

k =  -1.15501/-5  hr^-1     =  0.231002/hr

t_1/2 = 0.693/k  =  0.693/0.231002 hr^-1 =  3.00 hr

t_1/2 =   3 hr