Procedure for Water Loss Determination in Topical Preparations

1) Purpose

The purpose of this SOP is to outline the procedure for determining water loss in topical preparations to ensure stability and shelf-life.

2) Scope

This SOP applies to all topical preparations requiring water loss determination as part of stability testing to assess formulation integrity over time.

3) Responsibilities

Quality Control (QC) Department: Responsible for performing water loss determination.
Quality Assurance (QA) Department: Responsible for review and approval of water loss testing procedures and results.
Research and Development (R&D) Department: Responsible for providing formulation details and support during testing.

4) Procedure

4.1 Sample Preparation:
    4.1.1 Weigh a specific amount of the topical preparation into a pre-weighed container.
    4.1.2 Ensure samples are spread evenly in the container to maximize exposure to air.

4.2 Testing Conditions:
    4.2.1 Place containers in a controlled environment (e.g., stability chamber) set at specified temperature and humidity.
    4.2.2 Monitor test conditions throughout the testing period to maintain consistency.

4.3 Water Loss Measurement:
    4.3.1 Weigh containers at predetermined intervals to measure weight loss due to water evaporation.
    4.3.2 Calculate the percentage of water loss using initial and final weights of the containers.

4.4 Data Recording:
    4.4.1 Record weight measurements and calculate water loss percentages accurately.
    4.4.2 Document environmental conditions and any deviations observed during testing.

4.5 Reproducibility Testing:
    4.5.1 Repeat water loss testing on multiple samples from the same batch to confirm consistency.
    4.5.2 Ensure agreement in water loss measurements within acceptable variability limits.

4.6 Reporting:
    4.6.1 Prepare a Water Loss Determination Report summarizing test procedures, results, and conclusions.
    4.6.2 Include any observations regarding formulation stability and recommendations for storage conditions.
    4.6.3 Submit the report to QA for review and approval and maintain records as per facility procedures.

5) Abbreviations, if any

QC: Quality Control
QA: Quality Assurance
R&D: Research and Development

6) Documents, if any

Water Loss Determination Report
Sample Testing Records

7) Reference, if any

USP (insert appropriate reference for topical preparations)
FDA Guidance for Industry – Q1A(R2): Stability Testing of New Drug Substances and Products

8) SOP Version

Version 1.0