SOP Guide for Pharma

Elixir Department: SOP for Preservative Effectiveness Testing – V 2.0

Auditor

Elixir Department: SOP for Preservative Effectiveness Testing – V 2.0

Standard Operating Procedure for Preservative Effectiveness Testing (PET) in Elixir Formulations

Department Elixir Department
SOP No. SOP/ELX/218/2025
Supersedes SOP/ELX/218/2022
Page No. Page 1 of 9
Issue Date 11/04/2025
Effective Date 15/04/2025
Review Date 11/04/2026

1. Purpose

To define a validated method for conducting Preservative Effectiveness Testing (PET) to evaluate the antimicrobial preservative system used in elixir formulations and ensure protection against microbial contamination throughout the product’s shelf life.

2. Scope

This SOP applies to the QC Microbiology team for conducting PET on representative batches of preservative-containing elixirs as part of formulation development, stability studies, and regulatory submissions.

3. Responsibilities

  • QC Microbiologist:
    • Perform PET as per USP/Ph. Eur. method, maintain sterility, and ensure accurate enumeration.
  • QC Supervisor:
    • Verify inoculum preparation, test timelines, and microbial recovery results.
  • QA Officer:
    • Review PET protocol and approve results as part of formulation validation or product release.

4. Accountability

The QC Head is accountable for ensuring PET is executed correctly and meets compliance requirements. The QA Head is responsible for approving PET outcomes during regulatory and stability programs.

See also  Elixir Department: SOP for Handling Damaged Raw Material Packs - V 2.0

5. Procedure

5.1 Test Organisms

  1. Use the following test strains from recognized culture collections:
    • Staphylococcus aureus (ATCC 6538)
    • Pseudomonas aeruginosa (ATCC 9027)
    • Escherichia coli (ATCC 8739)
    • Candida albicans (ATCC 10231)
    • Aspergillus brasiliensis (ATCC 16404)

5.2 Inoculum Preparation

  1. Grow each microorganism in suitable media for 24–72 hours.
  2. Harvest and suspend in sterile peptone saline solution.
  3. Adjust inoculum to 1.0 × 107 to 1.0 × 108 CFU/mL using turbidity standard.

5.3 Product Inoculation

  1. Inoculate 20 mL of the elixir sample with 0.2 mL of each microbial suspension to achieve ~105 CFU/mL.
  2. Mix gently and incubate at room temperature (20–25°C) under controlled conditions.

5.4 Sampling Time Points

  • Day 0 – immediately after inoculation
  • Day 7 ± 1 day
  • Day 14 ± 1 day
  • Day 28 ± 2 days
See also  Elixir Department: SOP for Entry and Exit Procedure for Dispensing Area - V 2.0

5.5 Microbial Enumeration

  1. At each time point, withdraw 1 mL sample using aseptic technique.
  2. Perform serial dilutions in sterile buffer.
  3. Plate on appropriate agar (TSA for bacteria, SDA for fungi).
  4. Incubate bacteria at 30–35°C for 3–5 days, fungi at 20–25°C for 5–7 days.
  5. Count CFU and record results.

5.6 Acceptance Criteria (USP)

  1. Bacteria: Not less than 1.0 log10 reduction by Day 7 and no increase at Day 14 and 28.
  2. Fungi: No increase from initial count at Day 7, 14, or 28.
  3. Note: Pharmacopeial compliance may vary depending on intended use (oral, topical, etc.).

5.7 Documentation

  1. Record all observations in the Preservative Effectiveness Test Logbook (Annexure-1).
  2. Include CFU counts, growth curves, and conclusion in the PET report attached to BMR.

6. Abbreviations

  • PET: Preservative Effectiveness Test
  • SOP: Standard Operating Procedure
  • CFU: Colony Forming Units
  • USP: United States Pharmacopeia
  • QC: Quality Control
  • QA: Quality Assurance
See also  Elixir Department: SOP for Dispensing of Raw Materials for Elixirs - V 2.0

7. Documents

  1. Preservative Effectiveness Test Logbook (Annexure-1)
  2. Microbial Culture and Inoculum Records
  3. Batch Manufacturing Record (BMR)

8. References

  • USP Chapter <51> – Antimicrobial Effectiveness Testing
  • Ph. Eur. 5.1.3 – Efficacy of Antimicrobial Preservation
  • 21 CFR Part 211 – Current GMPs for Finished Pharmaceuticals

9. SOP Version

Version: 2.0

10. Approval Section

Prepared By Checked By Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Preservative Effectiveness Test Logbook

Date Batch No. Organism Initial Count (CFU/mL) Day 7 Day 14 Day 28 Result Tested By Checked By
11/04/2025 ELX-0425-036 Staphylococcus aureus 1.2 × 105 <10 <10 <10 Pass Rajesh Kumar Sunita Reddy

Revision History:

Revision Date Revision No. Revision Details Reason for Revision Approved By
01/01/2024 1.0 Initial Version New SOP Creation QA Head
11/04/2025 2.0 Updated log format and CFU time points Regulatory Alignment QA Head
Exit mobile version