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Dear all,
Is there any guideline for predose sample. At what time is acceptable
for predose in BE studies.
regards,
E.Srinivasa Reddy,
Research Analyst
Pharmacokinetics and Statistics Department
Bioserve Clinical Research Pvt.Ltd
Balanagar, Hyderabad, AP, India
email: esreddy.aaa.bioserve.co.in
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The following message was posted to: PharmPK
Dear Srinivasa,
FDA states in http://www.fda.gov/cder/guidance/5356fnl.pdf
at "Subjects with predose plasma concentrations:"
<>If the predose concentration is <= 5 percent of Cmax
value in that subject, the subject's data without any
adjustments can be included in all pharmacokinetic
measurements andcalculations. We recommend that if the
predose value is > than 5 percent of Cmax, the subject
be dropped from all BE study evaluations.
<>best regards,
Helmut
--
Helmut Schuetz
BEBAC
Consultancy Services for Bioequivalence and Bioavailability Studies
Neubaugasse 36/11
1070 Vienna/Austria
tel/fax +43 1 2311746
http://BEBAC.at
Bioequivalence/Bioavailability Forum at http://forum.bebac.at http://
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The following message was posted to: PharmPK
Dear helmut,
Thank for your reply. But my exact question is, At what time predose
sample
will be collected. i.e just before dosing, or 1 hr before dosing.
what is
exact time is better to collect predose sample.
regards
Srinivasa Reddy.
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The following message was posted to: PharmPK
Dear Reddy;Hi
In our team of bioeqivalences study at college of pharmacy, King Saud
University, after we preformed the canulation and checking for blood
glucose level as safe gard that the volunteer is in fasting state we
collecte the predose (usually between 15 to 30 minutes) before
administration of the dose. Hoping this of value to you.
Khalil I M Al-Khamis, Ph.D
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The following message was posted to: PharmPK
Dear Srinivasa,
now I got you question right!
>At what time predose sample will be collected.
>i.e just before dosing, or 1 hr before dosing.
>what is exact time is better to collect predose
>sample.
>
Referring to
W. Cawello (ed.);
Parameters for Compartment-free Pharmacokinetics.
Shaker, Aachen 2003 (pp.79)
"
When investigating the pharmacokinetics after
single dosing, the predose sample, except for endogenous
substances, is only used to demonstrate that there were
no quantifiable concentrations preceding drug administration.
This sample may therefore be taken within a reasonable
time span preceding drug administration e.g. within
30 minutes; nevertheless, it will be considered during
the calculations as if it had been taken simultaneously
with the drug concentration."
In my experience it would recommend to consider
30 minutes as a maximum, rather than a suggestion.
best regards,
Helmut
--
Helmut Schuetz
BEBAC
Consultancy Services for Bioequivalence and Bioavailability Studies
Neubaugasse 36/11
1070 Vienna/Austria
tel/fax +43 1 2311746
http://BEBAC.at
Bioequivalence/Bioavailability Forum at http://forum.bebac.at
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The following message was posted to: PharmPK
Dear Srinivasa,
As such there is no regulatory guidelines available, which suggest that
pre-dose should be collected at what exact time. It is just a measure to
ensure that there is no concentration of the analyte present to avoid
any error in estimation of the analyte.
What I have seen in many BA/BE studies in CRO's, it is a practice to
collect the blood for pre-dose about 1 hr before dosing and after that
cannulation and others measures before dosing can be taken.
Hope this helps
Regards
Tausif Ahmed, Ph.D.
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