Standard Operating Procedure for Release Rate Testing of Transdermal Patches

1) Purpose

The purpose of this SOP is to outline the procedure for conducting release rate testing of transdermal patches to ensure they meet the required release rate specifications.

2) Scope

This SOP applies to all release rate testing activities for transdermal patches manufactured within the facility, including sample preparation, testing, and documentation.

3) Responsibilities

The Quality Control Department is responsible for performing and documenting release rate tests as per this SOP. The QC Manager ensures compliance with the procedure and regulatory requirements.

4) Procedure

4.1 Sample Preparation

• 4.1.1 Select samples of transdermal patches from the production batch.
• 4.1.2 Condition the samples at 25°C and 60% RH for at least 24 hours before testing.
• 4.1.3 Label the samples with the batch number and date of preparation.
• 4.1.4 Document the sample details in the release rate testing logbook.

4.2 Testing Equipment

• 4.2.1 Ensure the dissolution test apparatus (e.g., USP Apparatus 5 or 6) is calibrated and in proper working condition.
• 4.2.2 Set up the equipment according to the manufacturer’s instructions.

4.3 Testing Procedures

• 4.3.1 Release Rate Measurement:
  • 4.3.1.1 Mount the transdermal patch onto a suitable support (e.g., a stainless steel disc or holder).
  • 4.3.1.2 Place the mounted patch in the dissolution vessel containing the release medium (e.g., phosphate buffer, pH 7.4).
  • 4.3.1.3 Set the temperature of the dissolution medium to 32°C ± 0.5°C.
  • 4.3.1.4 Start the apparatus and maintain a constant stirring rate (e.g., 50 rpm).
  • 4.3.1.5 Collect samples of the dissolution medium at specified time intervals (e.g., 1, 2, 4, 6, 8, 12, and 24 hours).
  • 4.3.1.6 Replace the withdrawn volume with fresh dissolution medium to maintain a constant volume.
  • 4.3.1.7 Analyze the collected samples using an appropriate analytical method (e.g., HPLC) to determine the amount of active ingredient released.
• 4.3.2 Calculation of Release Rate:
  • 4.3.2.1 Calculate the cumulative amount of active ingredient released at each time point.
  • 4.3.2.2 Plot the cumulative release data against time to generate a release profile.
  • 4.3.2.3 Determine the release rate from the slope of the linear portion of the release profile.

4.4 Interpretation of Results

• 4.4.1 Compare the release rate with the specified limits.
• 4.4.2 Document any deviations or out-of-specification results.

4.5 Documentation

• 4.5.1 Record all test results in the release rate testing data sheet.
• 4.5.2 Review and approve the release rate data before archiving.
• 4.5.3 Retain samples and records as per regulatory requirements.

5) Abbreviations, if any

RH: Relative Humidity
HPLC: High-Performance Liquid Chromatography

6) Documents, if any

Release Rate Testing Logbook
Release Rate Testing Data Sheets

7) Reference, if any

USP <724> Drug Release
ICH Q6A: Specifications: Test Procedures and Acceptance Criteria for New Drug Substances and New Drug Products: Chemical Substances

8) SOP Version

Version 1.0