SOP for Loss on Drying (LOD) Testing in Powders

Standard Operating Procedure for Loss on Drying (LOD) Testing in Powders

1) Purpose

The purpose of this SOP is to outline the procedure for determining the loss on drying (LOD) of powder formulations in the pharmaceutical industry to assess their moisture content.

2) Scope

This SOP applies to all personnel involved in loss on drying testing of powder formulations within the pharmaceutical quality control (QC) department.

3) Responsibilities

Analytical Chemist: Responsible for performing loss on drying testing and documenting results.
Quality Assurance (QA) Department: Responsible for reviewing and approving the loss on drying testing procedure and results.

4) Procedure

Sample Collection:
1. Select representative samples from different batches or lots according to the sampling plan.
2. Weigh each sample accurately using a calibrated balance.
Apparatus Setup:
1. Prepare the moisture balance according to manufacturer specifications.
2. Ensure the balance is calibrated and set to the appropriate drying temperature.
Testing:
1. Place the weighed sample into the moisture balance.
2. Start the drying cycle according to the predefined parameters (e.g., temperature, time).
3. Monitor the weight loss until a constant weight is achieved, indicating the completion of drying.
Calculation:
1. Calculate the loss on drying using the formula:
2. Loss on Drying (%) = [(Initial Weight - Final Weight) / Initial Weight] × 100
3. Where:
  - Initial Weight is the weight of the sample before

drying.

Final Weight is the weight of the sample after drying to constant weight.

Acceptance Criteria:

Compare the calculated loss on drying with established acceptance criteria for moisture content.
Evaluate the moisture content of the powder based on the loss on drying value.

Reporting:

Document the loss on drying test results in the appropriate logbook or electronic system.
Include any deviations noted during testing and actions taken.

Documentation:

Maintain accurate records of all loss on drying testing activities, including raw data, calculations, and reports.
File documentation following Good Documentation Practices (GDP).

5) Abbreviations, if any

SOP: Standard Operating Procedure
QC: Quality Control
QA: Quality Assurance
GDP: Good Documentation Practices

6) Documents, if any

Loss on Drying Testing Protocol, Test Results, Loss on Drying Report

7) Reference, if any

Pharmacopeial guidelines for loss on drying testing of pharmaceutical powders.

8) SOP Version

Version 1.0