Introduction
Sterile filtration is a critical step in pharmaceutical manufacturing, used to remove microorganisms and ensure sterility of liquid and gas products without the use of heat. It is widely applied in the production of injectable drugs, vaccines, and biological formulations where thermal sterilization is unsuitable.
1. Principle of Sterile Filtration
Sterile filtration relies on microporous membrane filters with absolute pore sizes typically ≤ 0.22 μm for liquids and ≤ 0.1 μm for gases. The filtration mechanism is based on size exclusion, surface adsorption, and depth capture to retain bacteria and other microorganisms.
核心原理可表示为：
若滤膜孔径 $r_p$ 满足：
$$ r_p < r_{min,\,microbe} $$
则细菌无法通过滤膜，从而实现无菌截留。
> 1. 液体或气体经滤膜微孔截留； > 2. 孔径控制与表面能确保细菌吸附与阻隔； > 3. 无需加热，避免产品组分损伤。