Purpose

Define user requirements for a standalone FUZKK utility that accepts laboratory CSV data, evaluates the records using limits embedded in code, and produces LabWare-compatible JSON.

Scope

The utility is intended for preliminary QC/QA review, integration testing, LIMS/LabWare flow and evidence-trail preparation. Final release decisions remain under the laboratory's validated procedure and responsible personnel.

Users

QC analyst, QA reviewer, CSV/validation engineer, LIMS/LabWare integration engineer, responsible laboratory specialist.

User requirements

1. The utility shall run without arguments and print its self-description, a built-in input.csv example from GetDemoData(), and demo evaluation for the embedded records.
2. The utility shall run with two arguments: input.csv output.json.
3. The utility shall not read input.csv and shall not write output.json when started without arguments.
4. CSV numeric values shall be parsed using CultureInfo.InvariantCulture.
5. Output shall be generated as LabWare-compatible JSON with Header, Samples, Results, Status, StatusCode, ErrorMessage, Description and DescriptionEN.
6. For PASS records, ErrorMessage shall be an empty string.
7. Embedded limits shall follow this priority: Ph. Eur. → British Pharmacopoeia / UK implementation → EAEU / regional requirements → EMA/ICH/EU guidance → USP fallback.
8. If an exact monograph is not known, strict standard API limits are used where applicable: assay 98–102%, total impurities ≤1.0%, individual impurity ≤0.5%.
9. For biologics and mAb-like products, aggregation, sterility and endotoxin checks shall be included where relevant to the utility purpose.
10. If a parameter may arrive in different units, the unit shall be represented as a separate input field or explicitly reflected in the input.csv field name.

Input CSV

BatchNumber,ProductName,DeviceType,InitialPressure_kPa,FinalPressure_kPa,HoldTime_sec,LeakRate_mbar_L_s,InternalResistance_kPa_L_min,ValveMisfires,BlisterPunctures_Failed
INH-LEAK-2026-001,Salbutamol HFA MDI,MDI,50.0,49.8,10.0,0.0005,0.0,0,0
INH-LEAK-2026-002,Budesonide DPI,DPI,0.0,0.0,0.0,0.0,4.2,0,0
INH-LEAK-2026-003,Tiotropium SMI,SMI,30.0,29.9,10.0,0.0008,0.0,0,0

input.csv fields

Utility description

Inhaler Leak Test Integrity Monitor — Inhaler Leak Test & Integrity Monitor

Inhaler Leak Test Integrity Monitor — Inhaler Leak Test & Integrity Monitor

ℹ️ Utility checks device tightness and mechanical integrity:
• Leak rate (≤0.001 mbar·L/s)
• Pressure drop during hold time
• Internal resistance (for DPIs)
• Valve misfires (for MDIs)
• Blister integrity (for DPIs)

⚠️ CRITICAL: Propellant leakage leads to device failure!
Moisture ingress destroys powder in DPIs.

Usage:
InhalerLeakTestIntegrityMonitor.exe → demo mode (console output)
InhalerLeakTestIntegrityMonitor.exe input.csv output.json → evaluate your data

Input format:
BatchNumber,ProductName,DeviceType,InitialPressure_kPa,FinalPressure_kPa,HoldTime_sec,LeakRate_mbar_L_s,InternalResistance_kPa_L_min,ValveMisfires,BlisterPunctures_Failed

Example:
INH-LEAK-2026-001,Salbutamol HFA MDI,MDI,50.0,49.8,10.0,0.0005,0.0,0,0

— WHY IS THIS NEEDED?
Leak testing is critical for safety and efficacy (AZ, GSK, Kindeva):
• For MDIs: Propellant leakage changes drug concentration and can lead to complete failure before expiry
• For DPIs: Breach in foil or housing integrity leads to moisture ingress and powder degradation
• Mechanical integrity of valves and blisters guarantees delivery of every dose
• Internal resistance affects patient's ability to generate required flow

⚠️ CRITICAL:
• Leak rate must be minimal (<0.001 mbar·L/s for MDIs)
• Pressure drop in leak test must not exceed limit
• Valve misfires are unacceptable (risk of patient missing dose)
• Unpunctured blisters mean lost dose
• DPI resistance must match specification for proper dispersion

Key features:
• Leak rate calculation from pressure decay data
• Mechanical defect check (valves, blisters)
• Aerodynamic resistance control
• Support for all inhaler types (MDI, DPI, SMI)

Critical parameters:
• Leak rate: ≤0.001 mbar·L/s
• Pressure drop: ≤0.5 kPa (during test)
• Valve misfires: 0
• Blister defects: 0

💡 Usage tips:
1. Perform leak test in thermostable conditions (temperature affects pressure)
2. Use helium leak detector for ultra-small leaks if vacuum method is insufficient
3. For DPIs, check packaging (blister/capsule) integrity separately from device
4. Measure resistance at standard flow (e.g., 60 L/min)
5. If leaks detected, check crimp quality (MDI) or foil sealing (DPI)

⚠️ Note: Inhaler tightness is directly linked to product shelf life. Even microscopic leakage in an MDI over 2-3 years storage will lead to significant propellant loss and altered spray characteristics. The utility helps reject defective devices at release stage.

Traceability and limitations

• The URS is used as the source document for functional specification, CSV review and later validation work.
• This document does not replace an approved pharmacopoeial monograph, validated analytical method or internal product specification.
• For product-specific limits, the approved customer specification takes priority.

The functional specification describes the behaviour of the standalone FUZKK console utility, input-data format, evaluation algorithm and output JSON structure.

Functional flow

1. Main() checks the number of arguments.
2. If no arguments are provided: PrintHello() prints the description and built-in input.csv example, then RunDemoEvaluation() executes Evaluate() over GetDemoData() and prints demo JSON.
3. If two arguments are provided: RunWithFiles(input.csv, output.json) reads CSV, evaluates each record and writes LabWare-compatible JSON.
4. LoadData() uses CultureInfo.InvariantCulture and shall not be called in no-arguments mode.
5. Evaluate() returns a named tuple with BatchNumber, ProductName, Parameters, CriticalFailCount, WarningCount, Recommendation and RecommendationEN.
6. GetIssues() builds messages for ErrorMessage in WARNING/FAIL cases.

Evaluation rules

• PASS: CriticalFailCount = 0 and WarningCount = 0.
• WARNING: CriticalFailCount = 0 and WarningCount > 0.
• FAIL: CriticalFailCount > 0.
• ERROR: exception during reading or processing.
• ErrorMessage remains empty for PASS.
• Limits are embedded in Program.cs; no external limit configuration is required.

Input and fields

BatchNumber,ProductName,DeviceType,InitialPressure_kPa,FinalPressure_kPa,HoldTime_sec,LeakRate_mbar_L_s,InternalResistance_kPa_L_min,ValveMisfires,BlisterPunctures_Failed
INH-LEAK-2026-001,Salbutamol HFA MDI,MDI,50.0,49.8,10.0,0.0005,0.0,0,0
INH-LEAK-2026-002,Budesonide DPI,DPI,0.0,0.0,0.0,0.0,4.2,0,0
INH-LEAK-2026-003,Tiotropium SMI,SMI,30.0,29.9,10.0,0.0008,0.0,0,0

Output JSON

{
  "Header": {
    "UtilityName": "Inhaler_LeakTest_Integrity_Monitor",
    "Version": "1.0.0",
    "Timestamp": "UTC",
    "InstrumentID": "FUZKK-QC-WORKSTATION",
    "OperatorID": "Admin"
  },
  "Samples": [
    {
      "SampleID": "from BatchNumber",
      "BatchNumber": "from CSV",
      "ProductName": "from CSV",
      "TestName": "utility-specific test",
      "AnalysisCode": "utility-specific code",
      "Status": "PASS | WARNING | FAIL | ERROR",
      "StatusCode": "1 | 2 | 0 | -1",
      "ErrorMessage": "",
      "Description": "Russian recommendation",
      "DescriptionEN": "English recommendation",
      "Results": [
        {
          "ParameterName": "parameter",
          "ResultValue": 0.0,
          "UnitOfMeasure": "unit",
          "SpecificationLimit": "limit",
          "IsWithinSpec": true
        }
      ]
    }
  ]
}