Microbial barrier test

Microbial ChaUenge/Product Sterility Test Methods. There are really two types of microbial barrier test those performed on materials and those performed on whole packages. Microbial barrier... 

Aerosol Challenge. At the risk of oversimplifying the procedural demands of microbial testing, here is a summary of how a microbial challenge/product sterility test is performed. There are two types of whole-package microbial barrier tests currently in use. 

Henke, C., and Reich, R., The Current Status of Microbial-Barrier Testing of Medical Device Packaging, MD DI, August 1992, pp. 46-49, 94. 

The integrity of the container-closure system as a microbial barrier should be assessed using an appropriately sensitive and adequately validated Container-closure Integrity Test. 

The stability studies for sterile drug products should include data from a sterility test of each batch at the beginning of the test period. Additional testing is recommended to demonstrate maintenance of the integrity of the microbial barrier provided by the container and closure system. These tests should be performed annually and at expiry. 

Integrity of the microbial barrier should be assessed using an appropriately sensitive and adequately validated container and closure integrity test. The sensitivity of this test should be established and documented to show the amount of leakage necessary to detect a failed barrier in a container and closure system. The number of samples... 

A rigorous approach to microbiological immersion challenge testing is depicted in Fig. 1. This method uses Pseudomonas diminuta grown in Lactose Broth at 3 rc for 24 h. The culture is then sonicated before use to break up any microcolonies or rosettes that may have arisen and that may reduce the potential for this microorganism to penetrate across tiny flaws in intended microbial barriers. 

The biggest concern over the use of recombinant microbes is that microbial cell walls constitute a permeability barrier for test compounds. Enzyme inhibitors that cannot accumulate in bacterial or yeast cytoplasm will appear as false nega-... 

The first set of requirements that closures for lyophilized product containers must meet are those described for stoppers used in containers for parenteral drugs. They must serve as a barrier to microbial contamination, be compatible with the formulated drug product, and not leach out toxic materials. They must be tested in the prescribed manner for seal integrity and product capability. The reader is referred to sections in the United States, European, and Japanese pharmacopoeias for appropriate test methods for evaluating extractables. 

Before we discuss how to test removal and destruction of the microbial skin flora, we must determine where the bacteria reside and how bacterial populations are maintained on the skin [6,7]. Gibbs and Stuttard [8] have described the skin as uneven in topology and thickness (Table 1), ridged, with openings of pores and ducts (Fig. 1). The skin may act as a physical barrier, though not as a chemical barrier. Both apocrine and eccrine secretions are vital to the microbial population, as well as repopulation after the removal of superficial flora. 

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