Standard Operating Procedure for Monitoring pH in Lyophilized Formulations

1) Purpose

This SOP outlines the procedures for monitoring and adjusting pH in lyophilized formulations, ensuring that pH levels are within acceptable ranges for optimal stability and activity of the product.

2) Scope

This SOP applies to formulation scientists, production operators, and QA personnel responsible for monitoring and adjusting pH levels during the preparation of lyophilized formulations.

3) Responsibilities

• Formulation Scientists: Responsible for determining the acceptable pH range for each formulation.
• Operators: Responsible for monitoring pH during formulation preparation and adjusting it as necessary.
• QA: Responsible for verifying the pH readings and documentation.

4) Procedure

4.1 Equipment Setup

• 4.1.1 Ensure that the pH meter is calibrated using standard buffer solutions (e.g., pH 4.0, 7.0, and 10.0) before use.
• 4.1.2 Ensure that all equipment and glassware used for pH monitoring is cleaned and sterilized.

4.2 pH Measurement

4.2.1 Sampling for pH

• 4.2.1.1 Take a small, representative sample of the formulation solution using a clean, sterilized pipette.
• 4.2.1.2 Place the sample in a clean container for pH measurement.

4.2.2 pH Measurement

• 4.2.2.1 Insert the calibrated pH probe into the sample and gently stir the sample to ensure accurate readings.
• 4.2.2.2 Record the pH value displayed on the meter.
• 4.2.2.3 If the pH is outside the specified range,