PK Censored Tail Reference Base Tool

Description

Compare already supplied research exposure areas; no tail extrapolation model or dose adjustment is inferred.

Pharmacokinetic research describes concentration over time using measurement units and an explicit model. Concentration-time area, its time-weighted moment, inverse-time rate constants, clearance, and volume are related but distinct quantities. A conversion or local model term does not estimate every parameter or validate a complete study.

Compare already supplied research exposure areas; no tail extrapolation model or dose adjustment is inferred.

When to use this tool

Use PK Censored Tail Reference Base when you need this concentration-time conversion, sampling check, local integral panel, or explicitly supplied kinetic-model term.

How to use the tool and how it works

Enter observedArea, suppliedTailArea, includeTail, referenceArea. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read reportedArea, tailShare, referenceRatio. Use the output convention below.

For nonnegative observedArea and suppliedTailArea and positive referenceArea return reportedArea=observedArea plus tail only if includeTail, referenceRatio=reportedArea/referenceArea, and tailShare=tail/(observed+tail) when their sum is positive, otherwise zero.^[1]

Input field	Meaning and units	Accepted input
observedArea	Observed Area	Required. Finite number; minimum 0.
suppliedTailArea	Supplied Tail Area	Required. Finite number; minimum 0.
includeTail	Include Tail	Required. Boolean.
referenceArea	Reference Area	Required. Finite number; strictly above 0.

Output field	Interpretation	Returned shape
reportedArea	Reported Area	Required. Finite number.
tailShare	Tail Share	Required. Finite number.
referenceRatio	Reference Ratio	Required. Finite number.

json

{
  "input": {
    "observedArea": 80,
    "suppliedTailArea": 20,
    "includeTail": true,
    "referenceArea": 50
  },
  "output": {
    "reportedArea": 100,
    "tailShare": 0.2,
    "referenceRatio": 2
  }
}

Limitations and assumptions

All areas share concentration-time units. TailShare always uses both terms regardless of includeTail; its all-zero result is a convention without a separate defined flag, not an estimated terminal tail.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Signed zero is exported as zero.

Alternative or Complementary methods

Use a complete study analysis when a local panel, transformation, or model factor is insufficient. Check sampling times, censoring, assay support, unit conventions, and the validity of the assumed kinetic regime.

References

Calculation and input contract: pharmacokinetics/pk-censored-tail-reference-base — tool.io

Similar or alternative tools

PK Noncompartmental Extrapolated Tail Share
For positive observedAuc and terminalRate and nonnegative lastConcentration return tailArea=lastConcentration/terminalRate, totalArea=observedAuc+tailArea, and extrapolatedFraction=lastConcentration/(terminalRate*observedAuc+lastConcentration).
PK Research Censored Concentration Interval
Interpret an explicitly supplied concentration censor token without imputing a value.