Standard Operating Procedure for Assay of Active Ingredient in Transdermal Patches

1) Purpose

The purpose of this SOP is to establish procedures for the quantitative determination of the active pharmaceutical ingredient (API) content in transdermal patches.

2) Scope

This SOP applies to assay testing activities conducted during the production and quality control of transdermal patches within the facility.

3) Responsibilities

The Quality Control (QC) Department is responsible for executing assay testing as per this SOP. Production personnel provide samples and facilitate testing activities.

4) Procedure

4.1 Sample Preparation

• 4.1.1 Obtain representative samples of transdermal patches from production batches according to approved sampling procedures.
• 4.1.2 Ensure samples are prepared in a manner that preserves API integrity and represents the entire batch.

4.2 Analytical Method Selection

• 4.2.1 Select a suitable analytical method for API assay, considering factors such as specificity, sensitivity, and precision.
• 4.2.2 Validate the chosen method according to established protocols (refer to SOP for Analytical Method Development for details).

4.3 Sample Analysis

• 4.3.1 Prepare calibration standards covering the expected range of API concentrations in transdermal patches.
• 4.3.2 Analyze sample solutions using the validated analytical method to quantify the API content.

4.4 Calculation and Acceptance Criteria

• 4.4.1 Calculate the API content in each sample based on calibration curve data and sample dilution factors.
• 4.4.2 Compare assay results against acceptance criteria specified in product specifications or regulatory guidelines.

4.5 Documentation and Reporting

• 4.5.1 Document all assay testing activities in batch records or testing logs, including details of sample preparation, analytical method used, calculations, and results.
• 4.5.2 Prepare assay test reports summarizing findings, deviations from acceptance criteria (if any), and any corrective actions taken.

5) Abbreviations, if any

SOP: Standard Operating Procedure
QC: Quality Control
API: Active Pharmaceutical Ingredient

6) Documents, if any

Sampling Procedures
Assay Method Validation Report
Batch Records

7) Reference, if any

ICH Q2(R1): Validation of Analytical Procedures
USP General Chapters on Assay

8) SOP Version

Version 1.0