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Dear Group,
Can anyone explain to me how to calculate Cumulative basolateral in caco-2 experiment.
and also how to calculate p app from the cumulative basolateral
Thanks and regards
Suma Singh
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The following message was posted to: PharmPK
Dear Suma,
Well, I guess it depends on your experimental design.
I believe this issue arises when you try to determine Papp accurately, i.e., following transport kinetics from the donor side to the receiver side.
Papp is related to the slope of the linear part of the time:cumulative transported amount curve (according to an equation which is given in numerous papers).
However, depending on the process you follow, the concentration that you measure in the receiver compartment may not represent the cumulative amount of compound which has crossed the barrier. Calculation of the cumulative amount transported will depend on the experimental design. If the insert has flown from well to well at each time point, it is straightforward: it would be the sum of the amounts from the first well. If the insert has remained over the same well and you have withdrawn some volume at each time point for analysis (that you may have replaced with fresh medium or not), then the calculation is a bit more complex, taking into account the withdrawn amounts and the dilutions if fresh medium has been added. However, it all comes down to a question of concentrations and volumes, and you should be able to figure out yourself the right way of calculating and build up the right spreadsheet. Eventually, the determination of Papp is accurate only if the sink conditions have been met (i.e., remain far from
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