Procedure for Water for Injection (WFI) Quality Testing

1) Purpose

The purpose of this SOP is to outline the procedure for testing the quality of Water for Injection (WFI) used in pharmaceutical manufacturing to ensure it meets specified standards for purity and suitability.

2) Scope

This SOP applies to all stages of WFI production, storage, and distribution within the facility, requiring regular testing to comply with pharmacopeial standards and internal specifications.

3) Responsibilities

Quality Control (QC) Department: Responsible for performing WFI quality testing.
Quality Assurance (QA) Department: Responsible for oversight and review of testing procedures.

4) Procedure

4.1 Sampling Points Identification:
    4.1.1 Identify critical sampling points where WFI quality will be tested (e.g., storage tanks, distribution points).
    4.1.2 Ensure sampling points cover different stages of WFI production and usage.

4.2 Sampling and Testing:
    4.2.1 Prepare sampling equipment, including sterile containers and validated sampling methods.
    4.2.2 Collect WFI samples according to aseptic sampling procedures, ensuring samples are representative of the source and usage points.
    4.2.3 Test WFI samples for key parameters such as conductivity, total organic carbon (TOC), microbial content, endotoxin levels, and specified ions (e.g., sodium, chloride).

4.3 Analytical Testing:
    4.3.1 Perform analytical tests using validated methods and equipment (e.g., conductivity meter, TOC analyzer, microbial enumeration methods).
    4.3.2 Follow pharmacopeial standards and facility specifications for sample preparation, testing conditions, and acceptance criteria.
    4.3.3 Record environmental conditions (e.g., temperature, pressure) during sampling and testing.

4.4 Data Analysis:
    4.4.1 Interpret test results and compare them against acceptance criteria for WFI quality.
    4.4.2 Evaluate trends over time to identify potential deviations or changes in WFI parameters.
    4.4.3 Investigate any out-of-specification results and implement corrective actions as necessary.

4.5 Reporting:
    4.5.1 Document all testing activities, including sampling locations, methods, results, and actions taken, in the WFI Quality Test Report.
    4.5.2 Provide summary reports to QA for review and approval.
    4.5.3 Maintain records of all testing documentation in accordance with facility procedures and regulatory requirements.

5) Abbreviations, if any

QC: Quality Control
QA: Quality Assurance
TOC: Total Organic Carbon
WFI: Water for Injection

6) Documents, if any

WFI Quality Test Report
Calibration Records for Testing Equipment
Analytical Method Validation Records

7) Reference, if any

USP Chapter XX – Pharmaceutical Water
FDA Guidance for Industry – Sterile Drug Products Produced by Aseptic Processing

8) SOP Version

Version 1.0