Stability_Shelf_Life_Predictor

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface, user requirements and functional behaviour of Stability_Shelf_Life_Predictor. The utility is intended for automated verification of laboratory, pharmacopoeial, analytical or manufacturing QC parameters using input.csv and producing a structured output.json result.

Domain limits and critical parameters

• • Real-time studies take years. Accelerated Testing allows rapid stability assessment.
• • Using kinetic models (Arrhenius equation) allows extrapolating high-temperature data to storage conditions.
• • Helps identify unstable formulations at early development stages.
• • Allows justification of preliminary shelf life for clinical batches.
• • Model assumes degradation mechanism does not change with temperature.
• • Activation Energy (Ea) strongly affects the result. If unknown, average value ~83 kJ/mol (20 kcal/mol) is used.
• • Prediction is valid only in temperature range where no phase transitions (melting, glass transition) occur.
• • For moisture-sensitive drugs, more complex model accounting for sorption isotherms is required.
• • Automatic calculation of degradation rate constant.
• • Application of Arrhenius equation for temperature correction.
• • Assessment of compliance with target shelf life (e.g., 2 or 3 years).
• • Predicted Shelf Life: >= Target (e.g., 2 years)
• • Degradation Kinetics: Zero/First Order assumption
• • Activation Energy: User defined or Default (83.14 kJ/mol)
• Shelf life determination is a key step in drug registration (ICH Q1A(R2)).
• 2. Check linearity of degradation over time (correlation coefficient R² > 0.9).

URS — User Requirements Specification

input.csv contract

BatchNumber,InitialAssay%,AccelAssay%,AccelTimeMonths,LowerSpec%,Ea_kJ
STAB-PRED-2026-001,100.0,98.5,6.0,90.0,83.14
STAB-PRED-2026-002,100.0,95.0,6.0,90.0,83.14
STAB-FAIL-2026-003,100.0,92.0,6.0,90.0,83.14

FS — Functional Specification

Example output.json

{
  "utilityId": "stability-shelf-life-predictor",
  "utilityName": "Stability_Shelf_Life_Predictor",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "STAB-PRED-2026-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "InitialAssay%",
      "value": "100.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "AccelAssay%",
      "value": "98.5",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "AccelTimeMonths",
      "value": "6.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "LowerSpec%",
      "value": "90.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Ea_kJ",
      "value": "83.14",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    }
  ],
  "criticalFindings": [],
  "warnings": [],
  "generatedFor": "QA/QC review and LIMS integration"
}

Traceability matrix

OQ/PQ test scenarios

QA/QC and change control

• Do not rename columns without updating the validator, documentation and test set.
• Retain input.csv, output.json, executable version, documentation and checksum.
• Before production use, perform IQ/OQ/PQ or equivalent CSV/CSA verification.
• Critical limits must be verified against the approved specification, local SOPs and registration dossier.