Standard Operating Procedure for Cleaning of Measuring Instruments in Elixir Manufacturing
| Department | Elixir Department |
|---|---|
| SOP No. | SOP/ELX/172/2025 |
| Supersedes | SOP/ELX/172/2022 |
| Page No. | Page 1 of 10 |
| Issue Date | 11/04/2025 |
| Effective Date | 15/04/2025 |
| Review Date | 11/04/2026 |
1. Purpose
To establish a uniform procedure for cleaning of measuring instruments used in elixir manufacturing, such as pH meters, weighing balances, thermometers, conductivity meters, and volumetric containers, to maintain accuracy, reliability, and prevent cross-contamination.
2. Scope
This SOP applies to all types of measuring instruments used in production and in-process control activities in the Elixir Department, including fixed and portable devices.
3. Responsibilities
- Production Operator:
- Perform cleaning of measuring instruments as per procedure.
- Ensure equipment is cleaned and dried before reuse or storage.
- QA Officer:
- Verify cleanliness, integrity, and record verification post-cleaning.
- Engineering Department:
- Ensure proper functioning of electronic instruments after cleaning.
4. Accountability
The Production Head is accountable for ensuring compliance. The QA Head is responsible for verification. The Engineering Head ensures protection of electronic integrity during cleaning operations.
5. Procedure
5.1 General
Precautions
- Disconnect all electrical equipment from power supply before cleaning.
- Handle precision instruments gently to avoid damage to sensitive components.
- Use only lint-free cloths, soft brushes, and approved cleaning agents.
5.2 Cleaning of pH Meters and Conductivity Meters
- Rinse electrode with purified water after each use.
- For stubborn residues, immerse in mild detergent solution (0.5–1%) for 5–10 minutes.
- Rinse thoroughly with purified water and dry with lint-free cloth.
- Store pH electrodes in storage solution or buffer as per manufacturer’s instructions.
5.3 Cleaning of Weighing Balances
- Switch off balance and unplug before cleaning.
- Remove weighing pan and clean with 70% IPA.
- Wipe external surfaces with lint-free cloth moistened with purified water or IPA.
- Ensure no liquid enters the internal compartment.
- Dry completely before reassembling and switching on.
5.4 Cleaning of Thermometers and Probes
- Use 70% IPA to wipe the surface gently.
- Ensure probes are not immersed beyond permissible limits.
- Dry using sterile compressed air or allow to air dry in clean environment.
5.5 Cleaning of Volumetric Measuring Devices
- Rinse graduated cylinders, beakers, and pipettes with purified water immediately after use.
- If sticky or colored residues are present, soak in non-ionic detergent solution for 15 minutes.
- Brush gently and rinse repeatedly with purified water until free of detergent (check for foam).
- Allow to dry inverted in a dust-free area.
5.6 Documentation
- Record each cleaning activity in the Measuring Instrument Cleaning Logbook (Annexure-1).
- Include instrument ID, date, time, cleaned by, verified by, and remarks.
6. Abbreviations
- SOP: Standard Operating Procedure
- QA: Quality Assurance
- IPA: Isopropyl Alcohol
- PW: Purified Water
7. Documents
- Measuring Instrument Cleaning Logbook (Annexure-1)
- Cleaning Agent Specification Sheet
8. References
- 21 CFR Part 211 – Equipment Cleaning and Maintenance
- ICH Q7 – GMP for Active Pharmaceutical Ingredients
- WHO TRS 986 Annex 4 – Cleaning of Equipment
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Measuring Instrument Cleaning Logbook
| Date | Instrument ID | Type | Cleaned By | Verified By | Remarks |
|---|---|---|---|---|---|
| 11/04/2025 | PHM-ELX-04 | pH Meter | Rajesh Kumar | Sunita Reddy | No residue |
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 01/01/2024 | 1.0 | Initial SOP Release | New SOP | QA Head |
| 11/04/2025 | 2.0 | Added drying guidance and storage handling | Compliance Update | QA Head |