When is F1 Evaluated

Hello, When is F1 evaluated? I am working on a model with nonlinear bioavailability and I need to know if F1 is evaluated during the entire absorption process or if it is evaluated upon the dose entering the dosing compartment. Thanks, Bill Notice: This e-mail message, together with any attachments, contains information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station, New Jersey, USA 08889), and/or its affiliates (which may be known outside the United States as Merck Frosst, Merck Sharp & Dohme or MSD and in Japan, as Banyu - direct contact information for affiliates is available at http://www.merck.com/contact/contacts.html) that may be confidential, proprietary copyrighted and/or legally privileged. It is intended solely for the use of the individual or entity named on this message. If you are not the intended recipient, and have received this message in error, please notify us immediately by reply e-mail and then delete it from your system.

Bill, F1 is evaluated at the instant that AMT enters CMT=1. If you want to modify F during absorption you will need to use something like this: $DES DADT(1) = -KA*A(1) ; gut loss (F1 will affect the AMT entering this CMT at the time of AMT record) FT=a+ b*A(1) ; some function of amount in CMT=1 DADT(2) = FT*KA*A(1) - CL*A(2)/V ; FT is a time varying fraction of the rate entering CMT=2 Nick Denney, William S. wrote: > Hello, > > When is F1 evaluated? I am working on a model with nonlinear bioavailability and I need to know if F1 is evaluated during the entire absorption process or if it is evaluated upon the dose entering the dosing compartment. > > Thanks, > > Bill > > Notice: This e-mail message, together with any attachments, contains > information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station, > New Jersey, USA 08889), and/or its affiliates (which may be known > outside the United States as Merck Frosst, Merck Sharp & Dohme or > MSD and in Japan, as Banyu - direct contact information for affiliates is > available at http://www.merck.com/contact/contacts.html) that may be > confidential, proprietary copyrighted and/or legally privileged. It is > intended solely for the use of the individual or entity named on this > message. If you are not the intended recipient, and have received this > message in error, please notify us immediately by reply e-mail and > then delete it from your system. -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand [email protected] tel:+64(9)923-6730 fax:+64(9)373-7090 mobile: +33 64 271-6369 (Apr 6-Jul 17 2009) http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford