Standard Operating Procedure for Water Activity Testing in Gels

1) Purpose

The purpose of this SOP is to establish procedures for measuring water activity in gels to assess product stability and quality.

2) Scope

This SOP applies to the Quality Control (QC) department responsible for performing water activity testing on gels manufactured at the pharmaceutical manufacturing facility.

3) Responsibilities

Quality Control (QC): Perform water activity testing according to defined procedures and standards.
Quality Assurance (QA): Oversee the implementation of water activity testing procedures and ensure compliance with SOPs and regulatory guidelines.
R&D or Formulation Development: Provide formulation details and stability data to support water activity testing.

4) Procedure

4.1 Sample Collection and Preparation
4.1.1 Collect representative samples from finished gel batches with documented batch/lot numbers and production records.
4.1.2 Prepare samples as per SOP to ensure uniformity and accuracy in water activity testing.

4.2 Water Activity Measurement
4.2.1 Calibrate the water activity meter using standard calibration solutions before testing.
4.2.2 Place the prepared sample in the water activity meter chamber and allow stabilization according to instrument specifications.
4.2.3 Record the water activity measurement displayed on the meter.

4.3 Interpretation of Results
4.3.1 Compare water activity measurement against specified acceptance criteria and stability limits.
4.3.2 Document water activity values for each tested sample.

4.4 Compliance Assessment
4.4.1 Evaluate water activity results for compliance with company-defined stability requirements.
4.4.2 Document compliance or non-compliance with water activity specifications.

4.5 Reporting and Documentation
4.5.1 Prepare detailed test reports documenting water activity results, compliance status, and any deviations.
4.5.2 Maintain accurate records of all water activity testing activities, including protocols, data sheets, and reports.

5) Abbreviations, if any

SOP: Standard Operating Procedure
QC: Quality Control
QA: Quality Assurance

6) Documents, if any

– Water Activity Testing Protocols and Procedures
– Calibration Reports for Water Activity Meter
– Test Reports and Data Sheets

7) Reference, if any

– Pharmacopoeial monographs (e.g., USP, Ph. Eur.) on water activity testing requirements
– Company-specific stability testing guidelines

8) SOP Version

Version 1.0