Standard Operating Procedure for pH Adjustment and Buffer Preparation in Nasal Spray Formulations

1) Purpose

The purpose of this SOP is to outline the procedures for pH adjustment and buffer preparation in nasal formulations to ensure product stability and efficacy.

2) Scope

This SOP applies to all personnel involved in adjusting pH and preparing buffers in nasal spray formulations at [Company Name].

3) Responsibilities

Operators: Responsible for accurately adjusting pH and preparing buffer solutions.
QA: Verifies pH readings and buffer preparation records.

4) Procedure

4.1 Preparation of Buffer Solutions

4.1.1 Equipment Setup

Ensure that all glassware and equipment used for buffer preparation are clean and calibrated.
Check pH meters for proper calibration using standard buffer solutions (e.g., pH 4.0, 7.0).

4.1.2 Buffer Solution Preparation

Prepare buffer solutions according to the specific formulation requirements.
Measure the appropriate amount of buffer salts (e.g., phosphate, acetate) and dissolve them in purified water.
Adjust the pH of the solution as needed using dilute acid or base.

4.2 pH Adjustment of Nasal Formulations

4.2.1 Initial pH Measurement

Measure the initial pH of the nasal formulation using a calibrated pH meter.
If the pH is outside the target range (e.g., pH 6.0 – 7.0), proceed to adjust it using a buffer solution.

4.2.2 pH Adjustment Procedure

Add small increments of the buffer solution to the formulation while continuously monitoring the pH.
Stir the solution thoroughly after each addition to ensure uniform pH distribution.
Stop the pH adjustment once the desired pH is achieved.

4.3 Documentation

Record all pH readings and buffer preparation details in the pH adjustment log.
Ensure that all records are signed off by QA personnel for accuracy and compliance.

5) Abbreviations, if any

QA: Quality Assurance

6) Documents, if any

pH Adjustment Log
Batch Manufacturing Record (BMR)

7) References, if any

ICH Q3A – Stability Testing Guidelines

8) SOP Version

Version 1.0

Annexure

pH Adjustment Log Template

Date	Formulation	Initial pH	Final pH	Operator Initials	QA Approval
DD/MM/YYYY	Formulation Name	Initial pH	Final pH	Operator Name	QA Name