Bioequivalence and Bioavailability Forum

Dear all
Looking at two patch products of one originator company I see the following

patch 1: to be applied for 4 days
patch 2: to be applied for 7 days

Both patches have the same size and drug content, the same excipients etc., so it seems that it is one and the same formulation. However, the releasing rates (product names, indications etc.) are different.

Releasing rate patch 1 x 24 h x 4 days gives the same amount of drug released from the patch as releasing rate patch 2 x 24 h x 7. However, this would imply that the patch stops releasing drug after day 3.

My question: Releasing rate = difference of drug content divided by time? Is it that simple?

Kind regards
Dan