pankajsojitra
☆    

India,
2020-04-19 11:15

Posting: # 21336
Views: 1,785
 

 long acting Injection [Design Issues]

Hi,

Hope all are well and safe.

Just need your help to understand one of aspect of study design as mentioned below.

Usually, 5 half-lives are considered for steady state in pharmacokinetic BE study.

But if it is mentioned in monograph that half-life is 17 days following single dose and 46 days after multiple dose, then which half-life we should consider while designing multiple dose study? In the same monograph, it is also stated that steady state is achieved after 4th dose on injection.

If we consider 17 days half life, then steady state achievement after 4th dose seems ok and we can proceed with 4, 5, 6 dose PK sampling. But if we consider 46 days (as it is with multiple dose and proposed study would also the same), then we need 9 monthly doses to build 5 half lives and 9, 10, 11 dose PK sampling.

Please guide in this regard.

Regards
Pankaj


Edit: Category and subject line changed; see also this post #1 &#2[Helmut]
jag009
★★★

NJ,
2020-04-21 21:06

@ pankajsojitra
Posting: # 21342
Views: 303
 

 long acting Injection

Hi,

» But if it is mentioned in monograph that half-life is 17 days following single dose and 46 days after multiple dose, then which half-life we should consider while designing multiple dose study? In the same monograph, it is also stated that steady state is achieved after 4th dose on injection.

Have you found out why the increase in half-life?

J
pankajsojitra
☆    

India,
2020-04-23 14:40

@ jag009
Posting: # 21346
Views: 279
 

 long acting Injection

» » But if it is mentioned in monograph that half-life is 17 days following single dose and 46 days after multiple dose, then which half-life we should consider while designing multiple dose study? In the same monograph, it is also stated that steady state is achieved after 4th dose on injection.
»
» Have you found out why the increase in half-life?

Hi J,

Nope, i am not able to find specific reason why half is increased after multiple doses despite the fact that this product doesn't accumulate.

Also it is known that half life following single dose more accurate rather than multiple doses (as there is profiling upto dosing interval only).

Look forward to hear for your comment on this.

Regards
Pankaj
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