Method Development (AMD) department involved in performing and verifying manual or electronic calculations related to assay, dissolution, content uniformity, stability testing, and impurity profiling.

3. Responsibilities

• Analyst: Performs analytical calculations and records results clearly in the worksheet.
• Reviewer/Scientist: Independently verifies all calculations for correctness and consistency.
• QA Personnel: Audits selected calculations during routine QA review or during validation report evaluation.

4. Accountability

The Head of AMD is responsible for ensuring proper verification of analytical calculations, availability of approved calculation templates, and adherence to GMP and GLP requirements.

5. Procedure

5.1 Calculation Types to be Verified

1. Assay percentage calculations
2. Impurity percentage and related substance estimations
3. Content uniformity calculations (Mean, RSD, AV)
4. Dissolution results (% release, average, SD)
5. LOD/LOQ estimations
6. Calibration curve slope and correlation coefficient (r²)
7. Degradation product quantification during stability studies

5.2 Calculation Verification Methods

1. Use a validated calculator, Excel spreadsheet, or CDS-integrated tool for independent re-calculation.
2. Cross-verify each input used in the calculation such as:
   • Sample weight
   • Dilution factors
   • Area of test and standard
   • Potency of standard
3. Ensure units are consistently used and any conversions are correctly applied.

5.3 Documentation of Verification

1. Reviewer must initial and date the verification next to the original calculation.
2. If electronic spreadsheets are used:
   • Print and sign the spreadsheet
   • Reference the version number and template ID used
3. Attach recalculation evidence as Annexure-1 with the worksheet.

5.4 Handling of Calculation Errors

1. Any identified calculation discrepancy must be:
   • Investigated for potential impact on reported results
   • Documented using deviation format (Annexure-2)
   • Corrected using GMP-compliant data correction practices (e.g., single line strike-through, date, and signature)

5.5 Use of Approved Calculation Templates

1. Only use QA-reviewed and version-controlled Excel templates or software systems for routine calculations.
2. All templates should be stored in a central server with access control and change log.
3. Analyst must ensure current version is in use before performing calculations.

5.6 Periodic Review and Audit

1. QA to conduct periodic review of templates and calculation verification logs to ensure compliance.
2. AMD Head to schedule quarterly audit of 10% randomly selected analytical reports for calculation integrity.

6. Abbreviations

• RSD: Relative Standard Deviation
• AV: Acceptance Value
• LOD: Limit of Detection
• LOQ: Limit of Quantitation
• CDS: Chromatographic Data System

7. Documents

1. Calculation Verification Record – Annexure-1
2. Calculation Error Deviation Format – Annexure-2
3. Approved Template Master List – Annexure-3

8. References

• ICH Q2(R1) – Validation of Analytical Procedures
• 21 CFR Part 211 – GMP for Finished Pharmaceuticals
• GAMP 5 – A Risk-Based Approach to Compliant GxP Computerized Systems

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Dr. Mansi Patel	Rohit Malhotra	Dr. Harshita Goyal
Designation	Senior Analyst	QA Officer	Head – AMD
Department	Analytical Method Development	Quality Assurance	Analytical Method Development

11. Annexures

Annexure-1: Calculation Verification Record

Includes sample ID, type of calculation, original result, verified result, reviewer name, signature, and date.

Annexure-2: Calculation Error Deviation Format

Deviation log for recording any miscalculations identified, including cause, impact assessment, corrective action taken.

Annexure-3: Approved Template Master List

Controlled list of calculation templates with template ID, description, version, date of approval, and owner.

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/06/2025	2.0	Added sections for electronic verification and template control	Annual review	Dr. Harshita Goyal
15/09/2022	1.0	Initial Release	New SOP	QA Head