Page 62 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

Preservative Efficacy Test: challenge test

• This test is applied to the formulated medicine in its final container to determine
• whether it is adequately protected against microbial spoilage.
• The test is provided to demonstrate, for multiple dose injectable, nasal, oral,

topical,
• and ophthalmic products made with aqueous bases or vehicles, the effectiveness of
• any added antimicrobial preservatives, the presence of which is declared on the
label of the product concerned.

• The tests and standards apply only to the product in the original, unopened
container in which it is supplied by the manufacturer

Choice of test microorganisms and inoculums preparation

• A preservative should be active against as wide a range of microorganisms as
possible hence the choice should be of both Gram-positive and Gram-negative
bacteria, yeasts and mold.

The test microorganisms used in preservative efficacy tests are

1) Staphylococcus aureus ATCC 6538,

2) Pseudomonas aeruginosa ATCC 9027,

3) Escherichia coli ATCC 8739,

4) Candida albicans ATCC 10231
Procedure:

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