drmuneesh
★    

2009-03-31 13:04
(6300 d 04:15 ago)

Posting: # 3422
Views: 5,113
 

 time points and study design [Design Issues]

Dear All

I am planning a BE study of Bicalutamide 150 mg tablet. The two (R) & (S) - enantiomers of Bicalutamide have different pharmacokinetics. Tmax of active (R)- enantiomer is 15-48 hr and that of inactive (S)- enantiomer is 2-5 hr. T1/2 of active (R)- enantiomer is about 1 week and that of (S)- enantiomer is 19 hr.

The study has been planned with the parallel truncated design upto 72 hrs and time points for blood sample collection are 0.00, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00, 8.00, 12.00, 14.00, 15.00, 16.00, 18.00, 24.00, 28.00, 32.00, 36.00, 40.00, 44.00, 46.00, 48.00, 50.00, 60.00 and 72.00.

Please suggest:
  1. Should we measure the racemate Bicalutamide or perform an enantiomer specific assay (i.e. active (R)- enantiomer)?
  2. Is the study design ok and are the time points selected for blood sample collection appropriate so as to capture the real Cmax?
  3. Is the 150 mg dose is safe in healthy human subjects?
  4. What should be the sample size?

Regards
Dr Muneesh Garg
MGR
★    

India,
2009-04-01 10:18
(6299 d 07:01 ago)

@ drmuneesh
Posting: # 3429
Views: 4,021
 

 time points and study design

Dear Dr.Muneesh Garg,

The following link may help you regarding the Design etc.,

USFDA Recommendation on Bicalutamide

And we have done the study on Healthy volunteers with an 50 mg dose for USFDA submission with 60 subjects and it passed both Fasting and Fed conditions.

Thank you,

Regards,
MGR
drmuneesh
★    

2009-04-02 13:10
(6298 d 04:09 ago)

@ MGR
Posting: # 3452
Views: 3,984
 

 time points and study design

Dear MGR

Thank you for the guidance. Can you please suggest the time points and safety of 150 mg dose in healthy human subjects.

Regards

Dr Muneesh Garg
martin
★★  

Austria,
2009-04-03 10:45
(6297 d 06:35 ago)

@ drmuneesh
Posting: # 3453
Views: 3,895
 

 selection of time points

dear drmuneesh !

selection of time points is discussed for example in this thread.

hope this helps

martin
drmuneesh
★    

2009-04-03 11:42
(6297 d 05:37 ago)

@ martin
Posting: # 3454
Views: 3,797
 

 selection of time points

Dear Martin

Thank you for the guidance. But in this case Tmax of active (R)- enantiomer is 15-48 hr and that of inactive (S)- enantiomer is 2-5 hr. Should I consider the Tmax of both the (R) & (S) - enantio­mers of Bicalutamide for deciding time points or only the active(R)- enantiomer which we are analyzing.

Also the Tmax range of 15-48 hr is quite wide. In this case how to decide the time points so as not to miss the real Cmax.

Please suggest.

Dr Muneesh Garg
martin
★★  

Austria,
2009-04-04 21:40
(6295 d 19:40 ago)

@ drmuneesh
Posting: # 3466
Views: 3,869
 

 BE study?

dear drmuneesh !

you are really planning a BE study when you know that the reference and test treatment have different pharmacokinetics (i.e. different shapes of the concentrations versus time curve) ?

martin
Ohlbe
★★★

France,
2009-04-05 01:38
(6295 d 15:41 ago)

@ martin
Posting: # 3469
Views: 3,806
 

 BE study.

Dear Martin,

Both the reference and the test product contain racemic bicalutamide. The question is then how to plan the sampling times, keeping in mind that the two enantiomers have different PK characteristics.

Regards
Ohlbe

Regards
Ohlbe
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