Bioequivalence and Bioavailability Forum

Hello Divyen!

❝ ❝ Cmax is due to the burst phase of release from the formulation however the plasma concentration required to produce therapeutic effect is very low i.e. < 5 % of Cmax and it remains in therapeutic range from Day 4 to 120 due to slow release of the product. It provides therapeutic effect for 4 months and then new injection has to be taken on day 120.

❝ This seems to be LAI and from initial post also a HVD?

Yes it is LAI.

❝ If by day 4- conc. are LT 5% of Cmax- then what is your half life? Why do you want to measure it for 120 days and the burst release doesn't have any toxicity impact? If even product name can not be shared- then it is difficult to be answered from very few details.

It is Leuprolide 30 mg 4-month injection. Since it is continuously released and as per OGD, AUC7-t is the primary PK parameter, we need to collect the sample for 112 days. Half-life doesn't matter for this continuous release product.

So how to calculate Swr when unequal carryover effect is present in full replicate study design?

Regads
Ankit