Rock
☆    

India,
2019-10-16 13:38

Posting: # 20691
Views: 868
 

 Emesis criteria for study comparing IR vs. MR formulations [Study Per­for­mance]

In a study comparing Test (Immediate Release) vs. Reference (Modified Release) formulations, on which formulations the withdrawal criteria on emesis should be based and why?


Edit: Category changed; see also this post #1. Please follow the Forum’s Policy[Helmut]
Helmut
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Vienna, Austria,
2019-10-16 13:53

@ Rock
Posting: # 20692
Views: 792
 

 Emesis criteria for study comparing IR vs. MR formulations

Hi Rock,

» In a study comparing Test (Immediate Release) vs. Reference (Modified Release) formulations, on which formulations the withdrawal criteria on emesis should be based …

For the IR formulation most people opt at two times the median tmax.
For the MR formulation the entire intended dosing interval.

» … and why?

IR: That’s the inflection point of the profile where absorption is essentially (98.44%) complete.
MR: Since you likely are facing flip-flop PK (where the late part of the profile represents absorption). Hence, for o.a.d. 24 hours, for b.i.d. 12 hours (even if you administered it only once).

Cheers,
Helmut Schütz
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nobody
nothing

2019-10-16 15:22

@ Helmut
Posting: # 20694
Views: 778
 

 Emesis criteria for study comparing IR vs. MR formulations

» MR: Since you likely are facing flip-flop PK (where the late part of the profile represents absorption).

...which is "very conservative", to say the least (and stay politicialy correct....)


btw. since when do you load scripts from cloudf**k for the forum? Don't like...

Kindest regards, nobody
Helmut
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Vienna, Austria,
2019-10-16 17:24

@ nobody
Posting: # 20695
Views: 765
 

 Almost OT

Hi nobody,

» » MR: Since you likely are facing flip-flop PK...
»
» ...which is "very conservative", to say the least (and stay politicialy correct....)

As usual: Know the drug, know your formulation. ;-)

» btw. since when do you load scripts from cloudf**k for the forum? Don't like...

Since I implemented MathJax to render [image] a couple of months ago. It was a wish of other members for years. That's the same open source script base which is used in R's documentation and Wikipaedia. I could keep a local copy on my server but then
  • I would have to check for updates regulary,
  • pages would render slower than from the cloud, and
  • I have to pay for more traffic.
If you don't like it, block JavaScript and practice reading plain [image].

Cheers,
Helmut Schütz
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nobody
nothing

2019-10-16 18:41

@ Helmut
Posting: # 20696
Views: 753
 

 Almost OT

» » btw. since when do you load scripts from cloudf**k for the forum? Don't like...
»
» Since I implemented MathJax to render [image] a couple of months ago. It was a wish of other members for years. That's the same open source script base which is used in R's documentation and Wikipaedia. I could keep a local copy on my server but then
  • I would have to check for updates regulary,
    »
  • pages would render slower than from the cloud, and
    »
  • I have to pay for more traffic.
If you don't like it, block JavaScript and practice reading plain [image].

OK, thanks for reply, script blocking remains ON, until absolutely necessary... ;-)

Kindest regards, nobody
Helmut
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Vienna, Austria,
2019-10-16 19:02

@ nobody
Posting: # 20697
Views: 750
 

 Completely OT

Hi nobody,

» OK, thanks for reply, script blocking remains ON, until absolutely necessary... ;-)

Sure, why not? Try this one. There is one difference to the implementation in Wikipaedia. If JS is not active, WP serves GIFs with the [image]-code in the alt-attribute of the <img> tag (for people who switched off graphis or rely on screen-readers). Would need a hell of coding here.

Cheers,
Helmut Schütz
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mittyri
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Russia,
2019-10-17 00:01

@ Helmut
Posting: # 20698
Views: 725
 

 median Tmax

Hi Helmut,

» For the IR formulation most people opt at two times the median tmax.

that's right, but in such case the PK scientist should know the median before the analysis starts, should he? Or to exclude the subject after PK analysis, when the median is calculated? Or should he use the published median Tmax?

Kind regards,
Mittyri
Helmut
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Vienna, Austria,
2019-10-17 08:42

@ mittyri
Posting: # 20699
Views: 708
 

 median Tmax

Hi mittyri,

» […] use the published median Tmax?

Yep – should be given in the SmPC/label. The exclusion should be done by the PI (or a sub-investigator). Sometimes I find statements like “the decision will be done by the pharmacokineticist after discussion with the sponsor” in protocols. Fishy.

Cheers,
Helmut Schütz
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jag009
★★★

NJ,
2019-10-22 21:26

@ mittyri
Posting: # 20713
Views: 541
 

 median Tmax

Hi,

» that's right, but in such case the PK scientist should know the median before the analysis starts, should he? Or to exclude the subject after PK analysis, when the median is calculated? Or should he use the published median Tmax?

You referring to reference? If so its usually stated in the protocol (usually).

J
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