A strange PK profile of an oral formulation

[wangwei1619]

Hi, all

Recently I have recived a PK result of a single administraiton of an oral formulation with, like this:

The absorption peak which should exist in first several hours seems disappeared in this figure. However, the first data point was measured at 0.5 h, which may result in absorption peak not recorded.
I think the figure is strange because drug is meatabolized quickly according to the profile before 15 h, but curve after 20 h seems to say it is not. Besides, how is the second peak formed, by enterohepatic circulation? Is it normal for a peak caused by enterohepatic circulation to be so high?
And is there any else potential reason to explain this phenomenon?

Thanks for comments.

[tobiasK2001]

Yes, indeed this looks strange and leaves more questions than answers. From the time course it looks like we have strong colonic absorption here. I guess we are in human? EHC peaks tend to occur after the first meal after dose e.g. 3-4 hours after last dose. Tablets are immediate release or controlled release? Compound is BCS 2 or 4?

[wangwei1619]

Oh, I should say this is data from beagle dogs. The chemical is lycopene, but it is formulated with PEG so that solubility is exceeding 800 ug/mL and it dissolves fast, but I don't know the exact permeability because I didn't receive such data. Is there any example of formulation behaving like this?

[RobinM92]

If it is lycopene, are both the trans and cis form measured or only one of the two? As the cis-isoform accumulates into micelles in vivo. Kind regards, Robin Dr. ir. Robin Michelet Senior scientist Freie Universitaet Berlin Institute of Pharmacy Dept. of Clinical Pharmacy & Biochemistry Kelchstr. 31 12169 Berlin Germany Phone: + 49 30 838 50659 Fax: + 49 30 838 4 50656 Email: robin.michelet@fu-berlin.de www.clinical-pharmacy.eu REGISTER NOW! 9th International Microdialysis Symposium; early bird: -15 May 2020

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On 22-06-20 9:53 AM, Wang Wei wrote: Oh, I should say this is data from beagle dogs. The chemical is lycopene, but it is formulated with PEG so that solubility is exceeding 800 ug/mL and it dissolves fast, but I don't know the exact permeability because I didn't receive such data. Is there any example of formulation behaving like this? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#554 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHKFXQ3OLLX5LUYK67XCWCDRX4EY3ANCNFSM4OCO6PWQ>.

[wangwei1619]

Hi, Robin

In fact, I don't know which type this lycopene is of. We have suspened this modeling work since we don't have enough supporting data. But, I still think this is a interesting example that I can keep in mind.

Thanks for your help.

Best regards,
Wamg Wei

[Yuri05]

@wangwei1619 Closing. Please reopen if there are still any unanswered questions.