Bioequivalence and Bioavailability Forum

Dear Bhupesh,

the Search field in the right above corner of the forum is your friend

dear bhupesh !

selection of sampling time points following a single dose is addressed for example on pages 133 to 134 in

Cawello W. (2003). Parameters for Compartment-free Pharmacokinetics. Standardization of Study Design, Data Analyes and Reporting. Shaker Verlag, Aachen.

[...] the blood sampling period should be continued for at least three-times preferably five-times the terminal half-life following tmax. [...] the time points for blood sampling are usually fixed as follows: the first five time points are selected before tmax (inclusive), the second five time points between tmax and t_1/2 (inclusive) and the last five time points between t_1/2 and five-times t_1/2 (inclusive) [...]

Note:

• you have to ensure that the bioanalytical methodology is able to measure concentrations above the limit of detection at time 5*t_1/2.
  
• in the case of an injection bolus, tmax is usually the first time point after study administration and you have to adopt this suggestions accordingly.
  
• there are guidelines for specific drugs explicitly stating sampling time points!

hope this helps

martin