in method development, validation, and routine analysis activities.

2. Scope

This SOP applies to all analytical balances installed and used in the AMD laboratories, including microbalances and top-loading balances, for routine weighing operations. It covers daily calibration checks, monthly verifications, and annual third-party calibration procedures.

3. Responsibilities

• Analytical Chemist: Performs daily and monthly internal calibration checks and records observations.
• Instrument Coordinator: Schedules annual calibration with an external certified agency and maintains calibration certificates.
• Quality Assurance: Verifies calibration status and reviews calibration records during internal audits.

4. Accountability

The Head of AMD is accountable for ensuring all analytical balances are calibrated as per the schedule and used only within the calibration validity period to maintain GMP compliance and data integrity.

5. Procedure

5.1 Calibration Classification

• Daily Calibration: Performed by the user with certified calibration weights before use each day.
• Monthly Verification: Conducted by the Instrument Coordinator using internal SOP-defined limits.
• Annual Calibration: Carried out by an external NABL-accredited agency with traceable standards.

5.2 Daily Calibration Procedure

1. Switch ON the balance at least 30 minutes before use.
2. Ensure the balance is clean and placed on a vibration-free surface.
3. Use certified calibration weights (Annexure-1).
4. Calibrate at three points: 10%, 50%, and 100% of balance capacity.
5. Record actual readings and calculate percent deviation from standard weight.
6. Acceptable deviation: ±0.1% of standard weight.
7. If deviation exceeds limits, inform QA and stop using the balance until corrective action is taken.

5.3 Monthly Verification Procedure

1. Perform same steps as daily calibration but include additional intermediate weight checks (e.g., 25%, 75%).
2. Record results in the Monthly Balance Calibration Log (Annexure-2).
3. Affix “Verified” label with date and initials.

5.4 Annual Calibration by External Agency

1. Schedule calibration at least 15 days before the due date.
2. Ensure agency is NABL-accredited and provides traceable calibration certificates.
3. Maintain a master calibration file including:
   • Certificate of calibration
   • Weight traceability reports
   • Calibration curves if applicable
4. Tag instrument with “Calibrated” sticker mentioning calibration date and due date.

5.5 Out-of-Tolerance (OOT) and Breakdown Management

1. If balance fails calibration:
   • Label as “Out of Service.”
   • Log deviation in instrument OOT Register (Annexure-3).
   • Initiate root cause analysis and document CAPA plan.
2. Balance may be recalibrated or repaired before being reinstated.

5.6 Documentation and Records

1. Ensure calibration records are filled completely, signed, and dated.
2. Preserve all logs for a minimum of 5 years or as per GMP document retention policy.
3. QA must verify calibration status during audits and batch reviews.

6. Abbreviations

• GMP: Good Manufacturing Practices
• NABL: National Accreditation Board for Testing and Calibration Laboratories
• OOT: Out of Tolerance
• QA: Quality Assurance
• SOP: Standard Operating Procedure

7. Documents

1. Annexure-1: Daily Calibration Checklist
2. Annexure-2: Monthly Calibration Log
3. Annexure-3: OOT Deviation Register
4. Annual Calibration Certificate File

8. References

• 21 CFR Part 211.68 – Automatic, Mechanical, and Electronic Equipment
• ICH Q10 – Pharmaceutical Quality System
• NABL Guidelines for Calibration Laboratories

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Ananya Sharma	Deepak Tiwari	Dr. Harshita Goyal
Designation	AMD Analyst	QA Reviewer	Head – Analytical Method Development
Department	Analytical Method Development	Quality Assurance	Analytical Method Development

11. Annexures

Annexure-1: Daily Calibration Checklist

Date	Weight Used	Observed Value	Deviation (%)	Status	Initials
01/06/2025	100 mg	100.02 mg	+0.02	Pass	AS

Annexure-2: Monthly Calibration Log

Date	Instrument ID	Weight Range	Status	Initials
31/05/2025	AMD-BAL-02	10 mg–200 g	Verified	DT

Annexure-3: OOT Deviation Register

OOT ID	Date	Description	Action Taken	Status
OOT-386-01	20/05/2025	100 mg deviation +0.3%	Re-calibrated by service team	Closed

Revision History

Revision Date	Revision No.	Details	Reason	Approved By
01/06/2025	2.0	Expanded sections on monthly and annual calibration	Annual SOP Review	Dr. Harshita Goyal
01/05/2022	1.0	Initial version	New SOP	QA Head