the API manufacturing unit. It includes physical verification, documentation, and suitability testing for continued analytical use.

3. Responsibilities

• QC Analyst: Perform monthly verification and record results in the Working Standards Verification Log.
• QC Store Officer: Maintain inventory of working standards and track expiry/retest dates.
• QA Officer: Review verification reports and authorize continued use or withdrawal.

4. Accountability

The Head of QC is accountable for ensuring that only qualified and verified working standards are used for analytical purposes and that verification logs are up to date.

5. Procedure

5.1 Identification and Traceability

1. Each working standard must be assigned a unique identification code (e.g., WS/YY/XXX).
2. The label on each container shall include:
   • Name of the compound
   • Source and batch number
   • Date of preparation
   • Purity
   • Assigned expiry/retest date
   • Storage conditions

5.2 Verification Frequency and Planning

1. Verify all active working standards on a monthly basis, preferably in the first week of each month.
2. Maintain a Master Verification Calendar (Annexure-1) to track due dates for all standards.
3. Review the verification schedule at the start of each month to plan testing.

5.3 Types of Verification

1. Perform the following tests for monthly verification:
   • Physical appearance (color, texture, clumping)
   • Assay or potency (against reference standard)
   • Loss on drying (if applicable)
   • Identification (IR or UV, as applicable)
2. Record all results in the Working Standards Verification Log (Annexure-2).
3. If retest is not possible due to insufficient quantity, inform QA and discontinue use.

5.4 Criteria for Acceptability

1. The working standard shall be considered suitable if:
   • Assay/potency is within ±2% of labeled value
   • No physical degradation is observed
   • Results of identification are positive
2. If any deviation is observed, report immediately to QC Head and QA.
3. Withdraw standard from use and quarantine until investigation is complete.

5.5 Documentation and Records

1. Make entries in the following logs:
   • Working Standards Master Register (Annexure-3)
   • Verification Log (Annexure-2)
   • Retest Calendar (Annexure-1)
2. Retain all verification worksheets and raw data for a minimum of 5 years.
3. Attach calibration certificate or source document (e.g., CoA) during initial qualification.

5.6 Requalification or Replacement

1. Requalify working standards:
   • At defined retest intervals (e.g., every 3 or 6 months)
   • Upon any change in source/reference standard
   • After storage excursions (temperature, humidity)
2. In case of expiry or failure, prepare a new lot of working standard and assign a new ID.
3. Document withdrawal and destruction using the Standard Withdrawal Form (Annexure-4).

5.7 Labeling Requirements

1. All labels must be waterproof, legible, and affixed securely.
2. Labels should be updated if:
   • Purity changes post-assay
   • Retest date is extended
   • Any requalification is done

6. Abbreviations

• QC: Quality Control
• QA: Quality Assurance
• WS: Working Standard
• CoA: Certificate of Analysis

7. Documents

1. Master Verification Calendar (Annexure-1)
2. Working Standards Verification Log (Annexure-2)
3. Working Standards Master Register (Annexure-3)
4. Standard Withdrawal Form (Annexure-4)

8. References

• ICH Q7 – Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients
• 21 CFR Part 211.84 – Testing and Approval or Rejection of Components
• WHO TRS No. 1019 – Annex 4

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Master Verification Calendar

WS ID	Compound	Retest Due	Status	Remarks
WS/25/001	Paracetamol	30/04/2025	Pending	Scheduled for Week 4

Annexure-2: Working Standards Verification Log

Date	WS ID	Assay (%)	LOD (%)	ID Test	Verified By	Status
10/04/2025	WS/25/001	99.6	0.3	Pass	Rajesh Kumar	Accepted

Annexure-3: Working Standards Master Register

WS ID	Compound	Source	Preparation Date	Purity (%)	Expiry
WS/25/001	Paracetamol	IP Reference Std	15/01/2025	99.6	15/07/2025

Annexure-4: Standard Withdrawal Form

Date	WS ID	Reason	Action Taken	Approved By
14/04/2025	WS/24/112	Expired	Disposed as per SOP	Sunita Reddy

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/01/2022	1.0	Initial SOP Release	New Implementation	QA Head
14/04/2025	2.0	Added LOD and monthly calendar format	Audit Suggestion	QA Head