Data Input

Load concentration-time data via file upload, manual entry, or Smart Parse.

File Upload / Manual Entry

Drop CSV/TSV file or click to browse
.csv, .txt, .tsv

Smart Parse

Instant

Paste anything — CSV, Excel table, JSON, or even a text description of your data. The AI will extract time-concentration pairs automatically.

Data Preview

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Analysis Configuration

Configure NCA parameters. Linear-up Log-down trapezoidal method with Best Fit λz selection.

Dosing Information

Required for CL, Vd, Vss calculations

Calculation Method

Linear-up Log-down Trapezoidal Rule
Ascending: linear trapezoid. Descending (both C > 0): log-linear trapezoid. C=0: linear fallback.
Best Fit λz Selection
Automated selection of terminal phase regression points using maximum adjusted R² criterion. Minimum 3 points, post-Tmax, C > 0, negative slope required.

Computed Parameters:

Cmax Tmax AUC(0-t) AUC(0-∞) AUMC(0-t) AUMC(0-∞) λz t½ MRT CL/F Vz/F Vss/F

NCA Results

Complete pharmacokinetic parameter estimates.

Primary PK Parameters

Run analysis to see results.

Terminal Phase Regression (λz)

Run analysis to see terminal phase details.

Interval Data (AUC/AUMC Buildup)

Run analysis to see interval data.

PK Profile Visualization

Concentration-Time Profile

Click data points to manually select terminal phase points for λz regression.

Terminal Phase Residuals

Validation & Benchmarks

Unit tests against published reference values using the Theophylline Subject 1 standard dataset.

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Methodology Reference

Linear-up Log-down Rule

Ascending (Ci+1 ≥ Ci):

AUC = (Ci + Ci+1) / 2 × Δt

Descending (Ci+1 < Ci, both > 0):

AUC = (Ci − Ci+1) / (ln Ci − ln Ci+1) × Δt

Zero concentration: Linear trapezoidal fallback

Best Fit λz Algorithm

  1. Identify Tmax (last occurrence if multiple Cmax)
  2. Consider only post-Tmax points with C > 0
  3. For n = 3 to N terminal points, perform OLS on ln(C) vs t
  4. Require: slope < 0, adjusted R² ≥ 0.80
  5. Select: maximum adjusted R², then maximum n (tiebreaker)

References

  • Gabrielsson J, Weiner D. Pharmacokinetic & Pharmacodynamic Data Analysis. 5th ed. 2016.
  • Rowland M, Tozer TN. Clinical Pharmacokinetics and Pharmacodynamics. 4th ed. 2010.
  • FDA Guidance for Industry: Bioanalytical Method Validation. 2018.