verifying that the pH is within the acceptable range.

Quality Assurance (QA): Ensures that pH monitoring is carried out according to this SOP and that the final product complies with the required pH specifications.

Production Team: Responsible for monitoring and adjusting the pH during the manufacturing process according to the guidelines specified in this SOP and the MFR.

4. Accountability

The Head of Creams Manufacturing is responsible for ensuring that pH monitoring is performed at the required stages of the cream manufacturing process. The QA Manager is accountable for ensuring compliance with this SOP and that any deviations from the specified pH range are addressed appropriately.

5. Procedure

5.1 pH Monitoring Equipment Preparation

1. Verify that all pH meters or pH probes used for testing are calibrated according to the manufacturer’s guidelines and are in proper working condition.
2. Ensure that the pH meter is clean and free from contamination that could affect the measurement accuracy. If using a probe, ensure that it is immersed in a pH calibration solution before use.
3. Prepare the necessary materials for measuring the pH, including calibration standards, distilled water, and appropriate containers for sampling.

5.2 Identification of Sampling Points

1. Identify the critical points during cream manufacturing where pH measurements need to be taken. These points typically include:
   • After emulsification to ensure the pH of the cream base is correct before adding active ingredients.
   • After homogenization to verify that the pH remains within the desired range.
   • Before packaging to confirm that the final product meets the required pH specification.
2. Ensure that pH measurements are taken at the specified intervals or stages as defined in the MFR to ensure consistency throughout the manufacturing process.

5.3 pH Measurement Procedure

1. At each sampling point, collect a representative sample of the cream formulation. Use clean, sterile containers to avoid contamination of the sample.
2. For each sample, insert the pH meter probe into the sample and allow it to stabilize. Ensure that the probe is fully immersed in the sample for accurate readings.
3. Record the pH value once the meter stabilizes. If the pH is within the acceptable range as specified in the MFR (typically between 4.5 and 6.5 for creams), proceed to the next step of production.
4. If the pH is outside the specified range, initiate corrective actions to adjust the pH. This may include adding pH-adjusting agents, such as citric acid or sodium hydroxide, in small, controlled amounts.
5. After adjusting the pH, retest the cream to ensure the pH has been corrected to the required range.

5.4 Corrective Actions for pH Deviation

1. If the pH of the cream formulation is outside the specified range, initiate corrective actions, such as:
   • Adding pH modifiers (e.g., citric acid, lactic acid, or sodium hydroxide) as specified in the MFR.
   • Re-evaluating the formulation to ensure the correct ingredients are being used and mixed properly.
   • Assessing whether any environmental factors, such as temperature or humidity, may have affected the pH during manufacturing.
2. Document all corrective actions taken in the batch record, including the amount of pH modifier added and the time of addition.

5.5 pH Adjustment Procedure

1. If the pH is too low (acidic), carefully add a small amount of an alkaline solution, such as sodium hydroxide, to bring the pH into the desired range. Ensure that the solution is added gradually to avoid overshooting the target pH.
2. If the pH is too high (alkaline), add a small amount of a mild acid, such as citric acid, to adjust the pH to the target range.
3. After adding any pH modifiers, mix the formulation thoroughly to ensure even distribution of the pH adjustment.
4. Retest the pH to verify that it falls within the acceptable range. Repeat the process if necessary until the pH is adjusted correctly.

5.6 Quality Control and Final pH Check

1. After the final pH adjustment, perform a final check of the pH at the designated point, typically before the product is transferred to the next stage of production or packaging.
2. Verify that the pH falls within the specified range in the MFR. If the final pH meets the required specification, proceed with the next step in the manufacturing process.
3. If the pH still does not meet the specification after multiple adjustments, investigate the issue and consult with the Formulation Development Team for possible reformulation or modification of the process.

5.7 Documentation and Reporting

1. Record all pH measurements, including the time of measurement, the sample number, and the pH value, in the batch record.
2. If any deviations from the required pH range occur, document the corrective actions taken and the results of any re-tests in the batch record.
3. Submit the batch record, including pH data, for review and approval by the QA team to ensure compliance with all quality standards.

5.8 Final Approval and Use of Cream

1. Once the cream formulation passes the pH test and all corrective actions have been documented, the cream is ready for further processing or packaging.
2. Ensure that all records related to pH testing and adjustments are properly filed and retained for future reference and regulatory compliance.

6. Abbreviations

• QC: Quality Control
• QA: Quality Assurance
• GMP: Good Manufacturing Practices
• API: Active Pharmaceutical Ingredient
• MFR: Master Formula Record

7. Documents

1. pH Monitoring Log (Annexure-1)
2. Batch Record (Annexure-2)
3. Quality Control Test Report (Annexure-3)

8. References

• Good Manufacturing Practices (GMP) Guidelines – 21 CFR Part 211
• International Conference on Harmonisation (ICH) Q7 – Good Manufacturing Practice for Active Pharmaceutical Ingredients
• FDA Guidelines for Cosmetics Manufacturing

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: pH Monitoring Log

Batch Number	Sampling Point	Time of Measurement	pH Value	Corrective Action
12345	Emulsification	08:00 AM	5.2	No action needed
12345	Homogenization	09:00 AM	6.1	Adjusted with citric acid

Annexure-2: Batch Record

Batch Number	Process Step	Time	Operator
12345	pH Monitoring	08:30 AM	John Doe

Annexure-3: Quality Control Test Report

Test Parameter	Result	Specification	Remarks
pH	5.2	4.5 – 6.5	Pass

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
01/03/2024	1.0	Initial Version	New SOP Creation	QA Head
01/03/2025	2.0	Format Revision and Updates	Standardization of Document	QA Head