Standard Operating Procedure for Microbial Testing in Cream Manufacturing
1) Purpose
The purpose of this SOP is to outline the steps required for microbial testing of creams in a pharmaceutical manufacturing setting to ensure they are free from harmful microorganisms and comply with microbiological quality standards.
2) Scope
This SOP applies to all personnel involved in the microbial testing of creams within the pharmaceutical production facility. It covers procedures for sample collection, preparation, and analysis for microbial contamination.
3) Responsibilities
It is the responsibility of the microbiology lab personnel to follow this SOP accurately and ensure that all microbial tests comply with GMP standards. The microbiology lab supervisor is responsible for overseeing the microbial testing process and ensuring proper documentation.
4) Procedure
4.1 Sample Collection and Preparation
4.1.1 Collect samples from each batch of cream according to the sampling plan, ensuring they are representative and uncontaminated.
4.1.2 Label each sample with the batch number, date of collection, and other relevant details.
4.1.3 Prepare the samples by diluting them appropriately in a sterile diluent, following standard microbiological methods.
4.2 Total Viable Count (TVC)
4.2.1 Preparation: Prepare a series of dilutions from the sample in sterile saline or phosphate buffer.
4.2.2 Plating: Plate the dilutions on suitable agar media (e.g., Plate Count Agar) using the pour plate or spread plate method.
4.2.3 Incubation: Incubate the plates at 30-35°C for 48-72 hours.
4.2.4 Counting: Count the number of colonies formed on each plate and calculate the TVC per gram or milliliter of the sample.
4.3 Pathogen Testing
4.3.1 Staphylococcus aureus:
4.3.1.1 Enrich the sample in Tryptic Soy Broth and incubate at 35-37°C for 24-48 hours.
4.3.1.2 Streak the enriched sample onto Mannitol Salt Agar and incubate at 35-37°C for 24-48 hours.
4.3.1.3 Identify typical colonies (yellow colonies surrounded by a yellow zone) and confirm using biochemical tests or molecular methods.
4.3.2 Pseudomonas aeruginosa:
4.3.2.1 Enrich the sample in Cetrimide Broth and incubate at 35-37°C for 24-48 hours.
4.3.2.2 Streak the enriched sample onto Cetrimide Agar and incubate at 35-37°C for 24-48 hours.
4.3.2.3 Identify typical colonies (greenish pigmentation) and confirm using biochemical tests or molecular methods.
4.3.3 Candida albicans:
4.3.3.1 Enrich the sample in Sabouraud Dextrose Broth and incubate at 20-25°C for 24-48 hours.
4.3.3.2 Streak the enriched sample onto Sabouraud Dextrose Agar and incubate at 20-25°C for 48-72 hours.
4.3.3.3 Identify typical colonies (creamy, smooth colonies) and confirm using biochemical tests or molecular methods.
4.4 Preservative Efficacy Test (PET)
4.4.1 Inoculate the cream sample with a known concentration of specific microorganisms (e.g., Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans).
4.4.2 Incubate the inoculated sample at specified conditions.
4.4.3 At specified time intervals (e.g., 7, 14, 28 days), take aliquots of the sample and determine the microbial count.
4.4.4 Evaluate the preservative efficacy by comparing the microbial counts over time against acceptance criteria.
4.5 Data Analysis and Reporting
4.5.1 Record all test results in the microbiological logbook and electronic database.
4.5.2 Compare the results against the specified acceptance criteria.
4.5.3 Generate a microbial testing report summarizing the findings and any deviations observed.
4.5.4 Submit the report to the Quality Assurance (QA) department for review and approval.
4.6 Cleaning and Maintenance
4.6.1 Clean all microbiological equipment and work areas according to the cleaning SOP to prevent cross-contamination.
4.6.2 Perform routine maintenance and calibration of microbiological equipment as per the maintenance schedule.
4.6.3 Record all cleaning and maintenance activities in the equipment logbook.
5) Abbreviations, if any
GMP: Good Manufacturing Practices
TVC: Total Viable Count
PET: Preservative Efficacy Test
6) Documents, if any
Microbiological Testing Logbook
Batch Manufacturing Record (BMR)
7) Reference, if any
ICH Q7: Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients
FDA Guidance for Industry: Microbiological Quality Considerations in Non-Sterile Drug Manufacturing
8) SOP Version
Version 1.0