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The following message was posted to: PharmPK
Does anyone know the effect of Tween-80 on PK?
I have a very soluble compound, and found that it has
a terrible PO PK with water as a vehicle. But when
20%captisol+2%Tween-80 was used as a vehicle, the PK
was improved dramatically: longer Tmax, almost 2xfold
higher AUC, and better bioavailability.
Anyone with any idea?
Thanks in advance,
Luke
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Dear Luke,
There are some evidences that tween 80 inhibits Pgp and CYP in gut.
Maybe, your compound is a subtrate of Pgp or CYP during
gastrointestinal absorption phase. So, the formulation with tween 80
improve the bioavailability through the inhibition of Pgp or CYP. On
the other hand, the tween 80 may have improve the solubility of your
drug and so the absorption.
Please look for some articles about it in Pubmed.
Regards,
Daniel Rossi de Campos
Brazil
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The following message was posted to: PharmPK
Dear Luke,
A quick google search pulled the following article up as one possible
explanation (see below). However, tween80 is an emulsifier, or surface
detergent, and thus cell membrane disruption is a likely mechanism for
increasing absorption (which it is well known for) and can not be
dismissed.
While the below hypothesis may also be true, I think you'd find
absorption is enhanced for more than just P-gp substrates.
-Joyce
Arch Pharm Res. 2003 Sep;26(9):768-72. Related Articles, Links
Commonly used surfactant, Tween 80, improves absorption of
P-glycoprotein substrate, digoxin, in rats.
Zhang H, Yao M, Morrison RA, Chong S.
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The following message was posted to: PharmPK
Luke, re effect of Tween 80.
Because your drug is very soluble, it may be a hydrotrope. So it may
be associating with itself in water. Surfactants are known to form
extended "mixed" micelles with hydrotropes, which could improve the
availability of the drug.
Frank Bales
Cardinal Health
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