Detecting and measuring microorganisms in liquid solutions is crucial for ensuring quality control in biotech and pharmaceutical applications. This involves bioburden testing and microbial limit testing, which membrane filtration is the preferred method for. However, filtering viscous substances like oily solutions, ointments, and creams can be challenging.

To comply with industry standards, such as USP <61>, Ph. Eur. 2.6.12, or JP 4.05, these products may be diluted with a sterile diluent like isopropyl myristate (IPM) or heated to 40-45 °C.

This study aimed to compare the time-saving benefits of dilution versus temperature elevation for filtering viscous samples.

Results showed that dilution with IPM had the greatest impact on filtration time, even at room temperature. This method is recommended by various pharmacopeias and allows for high throughput of viscous samples.

The Microsart^® @filter units are compatible with IPM, allowing a high throughput of viscous samples.

Download the Filtration of Viscous Samples for Microbiological Quality Control Application Note here.