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The following message was posted to: PharmPK
Dear,
The elimination half-life is determined by the
total clearance and the volume of distribution, i.e. t1/2 =
0.693Vd/CLTotal. CLTotal and Vd generally are the same for different
routes of administration. So the elimination half-life is usually
thesame for
different routes. If the absorption half-life (t1/2 abs) is
shorter than the elimination half-life (t1/2 el) , then the terminal
portion of the log Cp vs. t curve after per os administration will
parallel the curve after i.v. administration and in both cases reflect
the elimination half-life. But in cases where the elimination is
very rapid (ka << kel),the terminal slope may not be parallel because
the
kinetics ofdecline after oral administration reflects the absorption
half-liferather than the elimination half-life, which is an example
of"flip-flop" kinetics. In fact, the decline of the terminal slope
maydepend greatly on how fast absorption is taking place.
with best ragards....
Munvar.
PS:dear readers... i am a student of B.pharm..and i got some material
about flip-flop...so from that i posted the above matter.
--
Munvar Miya Shaik
B.Pharm(Hons.)
BITS, Pilani
Rajasthan-333031
Email: smart_munnu.aaa.yahoo.co.in
or f1999768.-at-.bits-pilani.ac.in
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