Bioequivalence and Bioavailability Forum • Use nominal times

Use nominal times [Software]

posted by fno – Belgium, 2014-04-02 19:16 (4459 d 05:33 ago) – Posting: # 12760
Views: 12,654

Dear Mittiry,

❝ Could you please clarify how did you calculate the bias for first (<1%) and second (>30%) example?

Assuming a local monoexponential phase around a sample planned at 1 h post-dose (sorry if that was not clearly specified):
C(t+t.dt)) = C(t)*exp(-k.dt)
[t = planned sampling time, dt = relative time deviation, and k = local rate constant = ln(2)/(local half-life)].

In the examples, assuming a true concentration C(t) = 100 at the planned sampling time:

Case 1, half-life = 8 h:
t1/2 = 8 -> k = 0.086643398
dt = -0.1 (sample taken 10% too early) -> C(t+t.dt) = 100.8701984 -> bias = 0.87%

Case 2, half-life = 15 min:
t1/2 = 0.25 -> k = 2.772588722
dt = -0.1 (sample taken 10% too early) -> C(t+t.dt) = 131.9507911 -> bias = 32%
dt = -0.03 (sample taken 3% too early) -> C(t+t.dt) = 108.6734863 -> bias = 8.7%

—
Kind regards,
Fabrice

Complete thread:

WNL, time deviations Beholder 2014-03-25 06:23
- Use nominal times fno 2014-03-25 09:47
  - Use nominal times Beholder 2014-03-27 07:50
    - Data binning Helmut 2014-03-27 13:47
      - Data binning Beholder 2014-03-28 08:08
      - Mean concentration curves – which mean #666 d_labes 2014-03-28 11:30
  - Use nominal times AngusMcLean 2014-03-29 13:06
    - Use nominal times mittyri 2014-03-29 14:45
  - Use nominal times mittyri 2014-03-31 20:31
    - Use nominal times fno 2014-04-01 17:48
      - Use nominal times Beholder 2014-04-02 08:23
        
        Use nominal timesfno 2014-04-02 17:16
      - SOPitis? Helmut 2014-04-02 11:57
        
        SOPitis? fno 2014-04-04 09:49
- WNL, time deviations SDavis 2014-04-24 15:10