Bioequivalence and Bioavailability Forum

❝ Please define your terms.

Free analyte available in systemic Vs. Conjugated drug.

❝ Are you referring by “free” to the fraction which is not protein-bound?

Yes.

Here i am talking about Scopolamine Patch 1/72 hrs. The label is talking about free as well as total Scopolamine (free + conjugated analyte). SBOA contains study which was approved in 2015 does not contain any bifurcation of total or free Scopolamine measurement.

As per my understanding, when half life is less i.e. <10 hrs and there is no major protein bounding, i believe what we are measuring is beyond the category of free or conjugated. As i believe, when there is a higher amount of protein binding, half life would be also high i.e. >20 hrs and more and clear information about drug conjugation should be defined.

please correct me if my understanding is not correct.

In such cases, where we have to measure free and total analyte, analytical methodology would also be different and must contain different extraction method to detect free as well as conjugated analyte.

Here label says metabolize profile of Scopolamine is not fully characterized.

Hope i could put my point in current manner and properly.

Regards,

Mithu