Standard Operating Procedure for Microbial Limit Testing of Elixir Formulations
| Department | Elixir Department |
|---|---|
| SOP No. | SOP/ELX/217/2025 |
| Supersedes | SOP/ELX/217/2022 |
| Page No. | Page 1 of 9 |
| Issue Date | 11/04/2025 |
| Effective Date | 15/04/2025 |
| Review Date | 11/04/2026 |
1. Purpose
To describe the procedure for determining the microbial limits in elixir formulations in accordance with pharmacopeial guidelines to ensure the product is free from harmful microbial contamination and suitable for consumption.
2. Scope
This SOP is applicable to Quality Control personnel responsible for testing finished elixir batches for Total Aerobic Microbial Count (TAMC), Total Yeast and Mold Count (TYMC), and specified microbial organisms.
3. Responsibilities
- QC Microbiologist:
- Prepare media, perform microbial testing, and record observations.
- QC Supervisor:
- Verify test conditions and ensure aseptic sampling practices are followed.
- QA Officer:
- Review and approve test results and initiate corrective action for OOS findings.
4. Accountability
The QC Head is accountable for ensuring proper microbial limit testing and documentation. QA Head is responsible for ensuring all results meet regulatory and internal standards.
5. Procedure
5.1 Sample Handling
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Collect a representative sample of the final product using sterile techniques.
Label containers properly with batch number, product name, and date of sampling.
Perform testing within 24 hours of sampling or store at 2–8°C until testing.
5.2 Media and Reagents
- Use media prepared as per pharmacopeial guidelines:
- Plate Count Agar for TAMC
- Sabouraud Dextrose Agar for TYMC
- Selective media for E. coli, Salmonella, S. aureus, P. aeruginosa
- Sterilize all media and equipment using validated autoclave cycles.
5.3 Sample Preparation
- Prepare a 1:10 dilution of the elixir sample using sterile 0.1% peptone water or buffer solution.
- If product contains preservatives, perform neutralization using validated neutralizing agents.
5.4 Plate Inoculation
- Inoculate 1 mL of diluted sample onto duplicate plates of Plate Count Agar and Sabouraud Dextrose Agar.
- Spread uniformly using a sterile spreader.
- For specified pathogens, inoculate 10 mL of sample into enrichment broth followed by plating onto selective media.
5.5 Incubation Conditions
- TAMC: 30–35°C for 48–72 hours
- TYMC: 20–25°C for 5–7 days
- Specified Microorganisms: As per individual test method (usually 24–48 hours)
5.6 Interpretation of Results
- Count colony forming units (CFU) and calculate per mL of sample.
- Acceptance Criteria (as per USP/Ph. Eur. for oral preparations):
- TAMC: NMT 103 CFU/mL
- TYMC: NMT 102 CFU/mL
- Specified Pathogens: Absent in 1 mL
5.7 Documentation
- Enter all results in the Microbial Limit Test Logbook (Annexure-1).
- Attach raw data sheets, incubation records, and CFU count photos to the BMR.
6. Abbreviations
- TAMC: Total Aerobic Microbial Count
- TYMC: Total Yeast and Mold Count
- CFU: Colony Forming Units
- SOP: Standard Operating Procedure
- QC: Quality Control
- QA: Quality Assurance
7. Documents
- Microbial Limit Test Logbook (Annexure-1)
- Incubation Records
- Batch Manufacturing Record (BMR)
8. References
- USP <61> – Microbial Enumeration Tests
- USP <62> – Tests for Specified Microorganisms
- 21 CFR Part 211.165 – Testing and Release for Distribution
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Microbial Limit Test Logbook
| Date | Batch No. | TAMC (CFU/mL) | TYMC (CFU/mL) | Specified Organisms | Tested By | Verified By |
|---|---|---|---|---|---|---|
| 11/04/2025 | ELX-0425-035 | 220 | 20 | Absent | Rajesh Kumar | Sunita Reddy |
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 01/01/2024 | 1.0 | Initial Release | New SOP | QA Head |
| 11/04/2025 | 2.0 | Included neutralization and TYMC method update | Regulatory Update | QA Head |