What is clinically relevant? [Design Issues]

posted by bebac_fan – US, 2018-04-06 20:53 (1593 d 22:40 ago) – Posting: # 18648
Views: 4,979

Dear Helmut:

I believe the spaghetti plots you posted are actually indicative of a infusion of unbound drug.

Release of the encapsulated form follows first order kinetics and is Sequential - kind of like metabolic clearance from parent --> metabolite.

Luckily, you also posted the parent/metabolite curve for doxorubinol. Because of similarity in process, if no free drug is infused, bound and unbound PK should follow the same general shape we see in parent + metabolite.

The fact that total + free dox concentrations are colinear is pretty strong evidence for co-infusion of bound + unbound. Further, the fact that there isn't a lag time in unbound, as well as a nonlinear shape, is evidence, too.


Complete thread:

UA Flag
 Admin contact
22,305 posts in 4,668 threads, 1,587 registered users;
online 13 (0 registered, 13 guests [including 8 identified bots]).
Forum time: Wednesday 19:33 CEST (Europe/Vienna)

There is no point in being precise when you don’t know
what you’re talking about.    attributed to John Tukey

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz