is to ensure that all working standards used in analytical procedures are consistent, reliable, and traceable to a qualified primary or secondary reference standard.

2. Scope

This SOP applies to all analysts and technical staff involved in the handling and preparation of working standards used for method development, system suitability, validation, and sample analysis within the AMD department.

3. Responsibilities

• Analytical Scientist: Prepares and qualifies the working standard and documents the Certificate of Analysis (CoA).
• QA Personnel: Reviews the qualification data and ensures compliance with documentation standards.
• Store Personnel: Manages storage conditions, usage records, and expiry tracking.
• Head – AMD: Approves qualified working standards for routine usage.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring that all working standards are properly prepared, qualified, labeled, and traceable to ensure data integrity and regulatory compliance.

5. Procedure

5.1 Source Material and Qualification Requirements

1. Use either a primary reference standard (e.g., USP, EP, IP) or a qualified secondary standard as the source for preparing the working standard.
2. The source standard must have an approved CoA and documented purity.
3. Record procurement details in Annexure-1: Working Standard Master Register.

5.2 Preparation Procedure

1. Weigh the required quantity (e.g., 500 mg to 1 g) of source standard in a clean, dry amber glass vial.
2. Seal with Teflon-lined cap and assign a Working Standard Code in the format: WS/YYYY/XXX.
3. Document batch preparation in Annexure-2: Working Standard Preparation Log.

5.3 Qualification of Working Standard

1. Prepare a standard solution of the working standard and compare against the reference standard using validated method.
2. Perform triplicate injections and calculate % assay and % RSD.
3. Acceptance criteria:
   • % Assay: 98.0–102.0%
   • % RSD: ≤ 2.0%
4. Document qualification in Annexure-3: Working Standard Qualification Form.
5. Prepare and approve the CoA before release.

5.4 Labeling

1. Label the vial with the following information:
   • Working Standard Name
   • Code No. (e.g., WS/2025/021)
   • Assay % and purity
   • Date of Preparation
   • Use Before Date
   • Storage Conditions
2. Affix label using solvent-resistant adhesive and store securely.

5.5 Storage and Handling

1. Store working standards in a desiccator or at 2–8°C depending on stability data.
2. Minimize light, moisture, and temperature fluctuations.
3. Record all withdrawals and usage in Annexure-4: Working Standard Usage Log.

5.6 Expiry and Requalification

1. Default validity: 12 months from preparation unless otherwise justified.
2. Requalification to be performed every 12 months or earlier based on visual inspection, OOS trends, or retest indication.
3. Expired material to be destroyed per QA-approved procedure.

6. Abbreviations

• AMD: Analytical Method Development
• CoA: Certificate of Analysis
• RSD: Relative Standard Deviation
• USP: United States Pharmacopeia
• EP: European Pharmacopoeia
• WS: Working Standard

7. Documents

1. Working Standard Master Register – Annexure-1
2. Working Standard Preparation Log – Annexure-2
3. Working Standard Qualification Form – Annexure-3
4. Working Standard Usage Log – Annexure-4

8. References

• ICH Q6A – Specifications: Test Procedures and Acceptance Criteria
• WHO TRS 996 – Good Practices for Pharmaceutical Laboratories
• USP General Chapter <11> – Reference and Working Standards

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Working Standard Master Register

WS Code	Name	Source Batch	Assay %	Prepared Date	Use Before
WS/2025/021	Amlodipine	USP12345	99.4%	02/05/2025	01/05/2026

Annexure-2: Working Standard Preparation Log

Date	Prepared By	Material	Qty (mg)	Remarks
01/05/2025	Rajesh Kumar	Amlodipine	500 mg	Clean, dry vial used

Annexure-3: Working Standard Qualification Form

WS Code	Assay %	RSD %	Qualified?	QA Reviewer
WS/2025/021	99.4%	1.2%	Yes	Sunita Reddy

Annexure-4: Working Standard Usage Log

Date	Used By	Purpose	Quantity Used	Balance
06/05/2025	Ajay Mehra	Method Validation	10 mg	490 mg

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
04/05/2025	2.0	Revised qualification form and extended stability guidance	Regulatory alignment