Elixir Department: SOP for Cleaning of Measuring Instruments – V 2.0

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