Lecture 11 Flashcards
What is the use of diluents in the analysis of pharmaceutical products?
Diluents are used to solubilize the sample material and disperse microorganisms into a suitable liquid medium for analysis. This allows for accurate enumeration and identification of any microorganisms present. The choice of diluent depends on the nature of the product being tested (e.g., Ringer’s solution).
What is the use of neutralizing agents in the analysis of pharmaceutical products?
Neutralizing agents are used when analyzing products containing antimicrobial preservatives. They counteract the inhibitory effects of preservatives, allowing for the accurate recovery and enumeration of microorganisms (e.g., Tween).
How are nonsterile samples typically submitted for analysis to the microbiology QC laboratory?
Containers: Samples should be submitted in their original containers. Sterility: Both sterile and non-sterile samples can be submitted. Transportation: Samples should be transported under appropriate conditions to prevent contamination. Contamination Control: Measures should be taken to prevent contamination during sampling and transportation. Record Keeping: All relevant data about the sample should be recorded.
Why are samples typically pretreated before microbiological analysis?
Pretreatment is essential for ensuring the accurate recovery and enumeration of microorganisms. Solubilization and Dispersion: Helps solubilize the sample and disperse microorganisms evenly. Removal of Inhibitory Substances: Removes or neutralizes antimicrobial substances present in the product. Release of Microorganisms: Methods like homogenization or shaking help release microorganisms from surfaces, making them accessible for detection.
Describe each of the following pretreatment methods for samples:
Homogenization: This method involves blending the sample with a diluent using a lab blender (e.g., a Stomacher). The Stomacher uses paddles to break down the sample, releasing microorganisms. Shaking: Shaking with sterile glass beads is used to mix the sample with small glass beads and shake vigorously. This technique helps release microorganisms from the sample’s surfaces, making it useful for powders. Pulverization: involves grinding the sample with a diluent or sterile sand using a pestle and mortar. This method has a lower recovery rate but is still used for certain sample types.
