Assessment of Differential Pressures Across Sterilizing Filter Membranes with Various Test Solutions

FDA recommends monitoring differential pressure across filter membranes during sterile filtration process validation. However, few resources are available to help pharmaceutical manufacturers anticipate expected differential pressures during sterilizing filtration of different solutions. To address this gap, Meissner evaluated differential pressures across different filtration membranes using various test solutions at increasing pump speeds. Specifically, we investigated differential pressures across sterilizing-grade PVDF, PES, and PTFE membrane discs, either in series or with downstream 0.4 μm PES analysis discs commonly used in bacterial retention testing. The test solutions employed for this study include saline, grapeseed oil, FBS, and DMEM cell culture media with 10% FBS. These solutions were chosen based on their differing physicochemical properties and their relevance to the pharmaceutical industry. This work will serve as a reference for pharmaceutical manufacturers and help them anticipate differential pressures across sterilizing filter membranes at different pump speeds based on the physicochemical properties of their drug products.