of expiration or requalification periods.

2. Scope

This procedure is applicable to all working standards prepared or procured for use in Analytical Method Development laboratories of the pharmaceutical organization, applicable for both API and finished product testing.

3. Responsibilities

• Analytical Chemist: Responsible for preparation, qualification testing, and documentation of WS.
• Standard Coordinator: Maintains the working standard inventory and coordinates analytical tests.
• QA Reviewer: Reviews the qualification report and ensures compliance with predefined specifications and ICH guidelines.

4. Accountability

The Head – Analytical Method Development is accountable for ensuring that all working standards are qualified, documented, and fit for purpose before use in any GMP-related testing.

5. Procedure

5.1 Receipt and Inspection

1. Upon receipt, inspect the reference or bulk material for integrity, container labeling, and documentation such as CoA or MSDS.
2. Ensure that the batch is from a GMP-compliant manufacturer or certified source.

5.2 Preparation of Working Standard

1. Weigh accurately a pre-defined quantity of the bulk API or intermediate material in a clean, dry container.
2. Homogenize thoroughly and divide into small aliquots (e.g., 100 mg to 1 g) depending on laboratory needs.
3. Label each vial with WS ID, lot number, date of preparation, and assigned validity.

5.3 Qualification Tests

The following analytical tests shall be performed using a certified reference standard (CRS):

1. Identification: Using IR, UV, or HPLC comparison with CRS.
2. Assay (Purity): Not less than 98.5% and not more than 101.5% relative to CRS.
3. Water Content: Using Karl Fischer titration if applicable.
4. Residual Solvents: Using Headspace GC as per ICH Q3C guidelines.
5. Melting Point / Boiling Point (if applicable)
6. Any Specific Tests: As required by monograph or internal specification.

5.4 Data Evaluation and Documentation

1. Compile all test results in the Working Standard Qualification Report (Annexure-1).
2. Compare with acceptance criteria. Any deviation should be documented and investigated.
3. Ensure at least three replicates for assay and ID testing.

5.5 Approval and Labeling

1. Submit qualification report for QA review and sign-off.
2. Upon approval, label vials with “QUALIFIED WORKING STANDARD”, WS code, potency, validity period, and analyst initials.
3. Enter qualified WS into WS Inventory Register (Annexure-2).

5.6 Retention and Storage

1. Store vials under specified conditions (e.g., 2–8°C, desiccated, protected from light).
2. Retain a portion as a reserve sample until WS expiration or batch discontinuation.

5.7 Requalification or Disqualification

1. Assign a requalification period (usually 6–12 months) based on stability or usage pattern.
2. Re-test for ID and assay. If WS fails, discard and prepare new WS batch.
3. Disposal of disqualified WS should follow SOP for hazardous waste (refer to SOP/AMD/321/2025).

6. Abbreviations

• WS: Working Standard
• CRS: Certified Reference Standard
• QA: Quality Assurance
• CoA: Certificate of Analysis

7. Documents

1. Working Standard Qualification Report – Annexure-1
2. WS Inventory Register – Annexure-2

8. References

• ICH Q6A – Specifications: Test Procedures and Acceptance Criteria
• ICH Q7 – Good Manufacturing Practice for Active Pharmaceutical Ingredients
• USP General Chapter <1058> on Analytical Instrument Qualification
• 21 CFR Part 211 – Subpart I: Laboratory Controls

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Ritika Anand	Ajay Thakur	Dr. Harshita Goyal
Designation	Analytical Chemist	QA Reviewer	Head – Analytical Method Development
Department	Analytical Method Development	Quality Assurance	Analytical Method Development

11. Annexures

Annexure-1: Working Standard Qualification Report

Test Parameter	Result	Limit	Compliance
Identification (HPLC)	Match with CRS	Complies	Yes
Assay	99.4%	98.5–101.5%	Yes
Water Content	0.7%	NMT 1.0%	Yes
Residual Solvents	Below limit	Per ICH Q3C	Yes

Annexure-2: WS Inventory Register

WS Code	Name	Batch No.	Prepared On	Expiry	Status
WS-IBU-2025	Ibuprofen	IBU-456	01/06/2025	01/06/2026	Qualified

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/06/2025	2.0	Expanded qualification tests and inventory structure	Annual Review	Dr. Harshita Goyal
01/07/2022	1.0	Initial release	New SOP	QA Head