conductivity monitoring during cleaning validation.

3. Responsibilities

• Production Operator: Operate the conductivity meter and perform measurements as per batch and cleaning procedures.
• QC Analyst: Verify calibration and results as needed for analytical or compliance purposes.
• Engineering: Maintain and service instruments per schedule.
• QA Officer: Review and retain conductivity measurement records.

4. Accountability

Production Head is accountable for proper usage and timely calibration. QA Head is responsible for ensuring data integrity and regulatory compliance.

5. Procedure

5.1 Instrument Check and Calibration

1. Verify calibration status before use. Calibration must be performed daily using certified standards (e.g., 84 µS/cm, 1413 µS/cm).
2. Record calibration details in the Conductivity Meter Calibration Log (refer Annexure-1).

5.2 Sample Collection

1. Collect process or cleaning solution samples in clean, dry glass beakers or plastic containers (non-reactive).
2. Ensure sampling point is flushed and representative of the bulk material.

5.3 Conductivity Measurement

1. Switch ON the instrument and allow stabilization for 5 minutes.
2. Rinse probe with distilled water and blot dry with lint-free tissue.
3. Immerse probe in sample ensuring full submersion of sensors.
4. Allow reading to stabilize (typically 30–60 seconds).
5. Record conductivity in µS/cm or mS/cm, along with temperature if auto-compensated.

5.4 Post-Measurement Cleaning and Storage

1. Rinse probe with distilled water after each use.
2. Store probe as per manufacturer’s instructions (e.g., in protective cap with storage solution).
3. Turn off the device when not in use.

5.5 Acceptance Criteria and Deviations

1. Refer to the BMR or cleaning protocol for conductivity limits (e.g., NMT 10 µS/cm for final rinse).
2. If out of limits, repeat measurement or escalate as deviation to QA.

5.6 Documentation

1. Enter results in the Conductivity Measurement Log (Annexure-2) and in-process or cleaning record.
2. Include date, time, batch number, sample type, and operator initials.

6. Abbreviations

• SOP: Standard Operating Procedure
• QA: Quality Assurance
• QC: Quality Control
• BMR: Batch Manufacturing Record
• µS/cm: Microsiemens per centimeter

7. Documents

1. Conductivity Meter Calibration Log (Annexure-1)
2. Conductivity Measurement Log (Annexure-2)
3. Batch Manufacturing Record / Cleaning Record

8. References

• ICH Q7 – Good Manufacturing Practice for Active Pharmaceutical Ingredients
• USP <645> – Water Conductivity
• 21 CFR Part 211 – US FDA GMP Guidelines

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Conductivity Meter Calibration Log

Date	Meter ID	Buffer Standard	Expected Value	Observed Value	Performed By	Remarks
13/04/2025	CD-101	1413 µS/cm	1413	1412		Pass

Annexure-2: Conductivity Measurement Log

Date	Batch No.	Stage	Reading (µS/cm)	Temperature (°C)	Measured By	Remarks
13/04/2025	API-20250413	Final Rinse	6.4	26		Complies

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/01/2022	1.0	Initial SOP Release	Instrument Usage Control	QA Head
13/04/2025	2.0	Updated calibration criteria and sample handling	Process Improvement	QA Head