Maik W. Jornitz

Maik W. Jornitz is vice-president of product management FT/FRT, Sartorius Stedim North America Inc., Edgewood, NY.

The authors discuss current and future disposable technologies and outline the validation and qualification steps that would be required for a possible disposable process stream.

The authors describe a novel approach for the integrity testing of large sterile filter systems such as multiround housings and describe a multipoint diffusion test capable of detecting minor failures.

Pre-use integrity testing of sterilizing-grade filters eliminates the potential adverse effects of filter loading on the integrity-test results, allowing unambiguous correlation with the integrity-test specification established during filter-validation studies.

Pore-size ratings are so unrelated to actual dimensions and so subject to anomalous interpretations as to make substantial dependency upon their values an unwise choice. Moreover, the means of measuring them are questionable. The pore-size rating system at best provides a qualitative differentiation.

Model organisms are useful when validating sterile filtration, but successful retention of the model organism does not always guarantee that effluent is sterile. The authors explore the various factors that influence sterile filtration.

The authors encourage the investigation into whether the occurrence of grow-through and the diminution in the size of certain organisms when in contact with given liquids are the same phenomenon manifested under different circumstances.

This article critiques the diffusive-airflow and bubble-point tests for their comparative suitability for integrity testing in pharmaceutical processes.