Bioequivalence and Bioavailability Forum

Dear HS.
I always appreciate informations on this web site.

By the way, I have some questions.

I have calculated AUCinf-pred (Method #5) according to your explanations.
But, I couldn't get the same result as you did.

So, I present the calculation process at a lower column.
Please check my calculation

1. Concentration raw data (you have already presented)
┌──────┬──────┬──────┐
│  t   │ ref  │ test |
├──────┼──────┼──────┤
│ 0.00 │ 0.00 │ 0.00 |
│ 0.50 │29.83 │28.34 |
│ 0.71 │37.60 │35.72 |
│ 1.01 │45.29 │43.02 |
│ 1.44 │51.28 │48.72 |
│ 2.05 │53.49 │50.82 |
│ 2.91 │50.43 │47.91 |
│ 4.14 │42.10 │39.99 |
│ 5.89 │30.51 │28.99 |
│ 8.37 │18.73 │17.79 |
│11.90 │ 9.25 │ 8.79 |
│16.92 │ 3.39 │ 3.22 |
│24.00 │ 0.82 │ 0.78 |
└──────┴──────┴──────┘

2. AUCt calculation (by Method #1)
┌─────────────────┬──────────┬──────────┐
│      AUC        │  ref     │  test    |
├─────────────────┼──────────┼──────────┤
│ AUC(0.00~0.50)  │  7.45750 │  7.08500 |
│ AUC(0.50~0.71)  │  7.08015 │  6.72630 |
│ AUC(0.71~1.01)  │ 12.43350 │ 11.81100 |
│ AUC(1.01~1.44)  │ 20.76255 │ 19.72410 |
│ AUC(1.44~2.05)  │ 31.95485 │ 30.35970 |
│ AUC(2.05~2.91)  │ 44.68560 │ 42.45390 |
│ AUC(2.91~4.14)  │ 56.90595 │ 54.05850 |
│ AUC(4.14~5.89)  │ 63.53375 │ 60.35750 |
│ AUC(5.89~8.37)  │ 61.05760 │ 58.00720 |
│ AUC(8.37~11.90) │ 49.38470 │ 46.91370 |
│ AUC(11.90~16.92)│ 31.72640 │ 30.14510 |
│ AUC(16.92~24.00)│ 14.90340 │   -      |
│ AUCt            │401.88595 │367.64200 |
└─────────────────┴──────────┴──────────┘

3. Clast calculation
┌───────────┬──────────┬──────────┐
│ parameter │    ref   │   test   │
├───────────┼──────────┼──────────┤
│ slope     │ -0.20027 │ -0.19992 │
│ intercept │  4.60838 │  4.55224 │
└───────────┴──────────┴──────────┘

2.1. Calculation of C_last
- ref (last time = 24.00)
: 0.82 × (-0.20027)+4.60838 = -0.19804
--> e^(-0.19804) = 0.82033

- test (last time = 16.92)
: 3.22 × (-0.19992)+4.55224 = 1.16956
--> e^(1.16956) = 3.2206

3. AUCinf-pred calculation
Formula : AUCt + Clast/Kel

1) AUCinf-pred of ref
= 401.99585 + 0.82033/0.20027
= 405.98213

2) AUCinf-pred of test
= 367.64200 + 3.22059/0.19992
= 383.75213

These values are not same your values.
- AUCinf-pred of ref : 405.98213(I) vs 405.93053 (yours)
- AUCinf-pred of test : 383.75213(I) vs 383.74829 (yours)

There's some severe mistakes in my calculation? (please check..)

And, could you please explain why AUCinf-pred is not a same value between us?

best regards,
Jungmin Lee

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Edit: Full quote removed. Please see this post! [Ohlbe]