lag-time – another round [Design Issues]
Hi Titus,
By convention in NCA BQLs before tmax are set to zero. Of course, 0 cannot be shown in a log-linear plot. By another convention, tlag is defined as the time point before the first measurable concentration. Obviously that’s not correct (see also there). The true one is a little later. Another approach1 is not implemented in any software; roll out your own code. Of course, you can estimate tlag by a PK model.2
❝ But clearly in the plot, there is no significant lag time.
❝ I believe, lag-time can be only observed in normal Conc-time plot. Isn't?
By convention in NCA BQLs before tmax are set to zero. Of course, 0 cannot be shown in a log-linear plot. By another convention, tlag is defined as the time point before the first measurable concentration. Obviously that’s not correct (see also there). The true one is a little later. Another approach1 is not implemented in any software; roll out your own code. Of course, you can estimate tlag by a PK model.2
- Csizmadia F, Endrényi L. Model-Independent Estimation of Lag Times with First-Order Absorption and Disposition. J Pharm Sci. 1998; 87(5): 608–12. doi:10.1021/js9703333
- In all exponential functions substitute \(\small{t}\) by \(\small{(t-t_\text{lag})}\) with the fitting constraint \(\small{t_\text{lag}\ge 0}\).
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- PK Sampling Time Points - SR Formulation TitusBen 2024-10-17 05:40 [Design Issues]
- PK Sampling Time Points - SR Formulation Helmut 2024-10-17 10:56
- PK Sampling Time Points - SR Formulation TitusBen 2024-10-18 06:24
- PK Sampling Time Points - DR Formulation Helmut 2024-10-18 09:16
- PK Sampling Time Points - DR Formulation TitusBen 2024-10-18 16:45
- lag-time – another roundHelmut 2024-10-19 08:20
- PK Sampling Time Points - DR Formulation TitusBen 2024-10-18 16:45
- PK Sampling Time Points - DR Formulation Helmut 2024-10-18 09:16
- PK Sampling Time Points - SR Formulation TitusBen 2024-10-18 06:24
- PK Sampling Time Points - SR Formulation Helmut 2024-10-17 10:56