testing activities within the laboratory.

2. Scope

This SOP is applicable to all working standards derived from certified reference standards, pharmacopeial standards, or in-house standards for use in quality control or analytical method development.

3. Responsibilities

• Analytical Chemist: Prepares, labels, and submits working standard samples for analysis.
• QA Reviewer: Reviews documentation and approves the working standard based on predefined acceptance criteria.
• Documentation Officer: Maintains logs, COA copies, and calibration data for all approved working standards.

4. Accountability

The Head of Analytical Method Development is accountable for the proper implementation of this SOP and ensuring compliance with applicable regulatory and quality requirements for reference material handling.

5. Procedure

5.1 Procurement and Receipt of Reference Standard

1. Obtain pharmacopeial reference standards (USP, BP, EP, IP) or certified in-house reference standards.
2. Verify COA and expiration date upon receipt.
3. Record batch number, potency, and expiry date in Reference Standard Receipt Log (Annexure-1).

5.2 Preparation of Working Standard

1. Weigh appropriate quantity of reference standard in a clean and dry container using calibrated balance.
2. Mix and homogenize thoroughly to ensure consistency.
3. Store the working standard in airtight, labeled amber bottles.
4. Label must include:
   • Material name
   • Batch number
   • Prepared by and date
   • Potency and storage conditions

5.3 Characterization and Qualification

1. Determine the following parameters:
   • Identity by IR or UV
   • Assay by validated method (minimum 3 replicates)
   • Moisture content by KF titration
   • Any additional tests as per product-specific requirement
2. Calculate potency using assay value and LOD correction, where applicable.
3. Enter results in Working Standard Qualification Sheet (Annexure-2).

5.4 Approval and Release

1. Submit the qualification sheet and COA to QA for review and approval.
2. On approval, assign working standard ID and enter in Working Standard Register (Annexure-3).
3. Distribute small aliquots to analysts with usage log and instructions for handling.

5.5 Re-Qualification and Expiry Monitoring

1. Working standards should be re-qualified every 6 months or based on usage pattern.
2. Record re-qualification data in Annexure-2 under new entry date.
3. Destroy expired standards as per SOP for disposal and update the register accordingly.

6. Abbreviations

• COA: Certificate of Analysis
• LOD: Loss on Drying
• KF: Karl Fischer
• USP: United States Pharmacopeia
• IR: Infrared Spectroscopy

7. Documents

1. Annexure-1: Reference Standard Receipt Log
2. Annexure-2: Working Standard Qualification Sheet
3. Annexure-3: Working Standard Register

8. References

• ICH Q6A – Specifications: Test Procedures and Acceptance Criteria
• USP General Chapter <11> – Reference Standards
• WHO TRS 996 – Quality Control of Pharmaceutical Products

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Deepika Sharma	Neeraj Thakur	Dr. Rakesh Shetty
Designation	Analytical Chemist	QA Reviewer	Head – AMD
Department	Analytical Method Development	Quality Assurance	Analytical Method Development

11. Annexures

Annexure-1: Reference Standard Receipt Log

Date	Standard Name	Source	Batch No.	Potency	Expiry	Received By
28/05/2025	Paracetamol CRS	USP	PSM-023	99.6%	31/12/2026	D. Sharma

Annexure-2: Working Standard Qualification Sheet

Includes data on IR spectra, assay result, moisture content, calculated potency, and QA approval signature.

Annexure-3: Working Standard Register

WS ID	Material	Preparation Date	Potency	Expiry	Requalified On
WS/AMD/101	Paracetamol	30/05/2025	99.4%	30/11/2025	—

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/06/2025	2.0	Updated requalification interval and moisture analysis requirement	Annual SOP review	Dr. Rakesh Shetty
10/08/2022	1.0	Initial release	New SOP	QA Head