Polyvinylidene membrane technology

Another assay that has gained popularity and acceptance for the evaluation of permeability is the parallel artificial membrane permeability assay (PAMPA). Earlier versions of this system coated polyvinylidene fluoride (PVDF) filter plates with artificial membrane using dioleoyl-sn-glycerol-3-phosphocholine (Chen et al., 2008). Several companies attempted to develop this technology in the late 1990s with limited success (Kansy et al., 1998). These earlier versions suffered poor correlation to cell models, poor correlation to human absorption, and poor reproducibility. More modem systems have been developed with different lipid formulations and solvation techniques that seem to correlate better with Caco-2 and human data and are more reproducible (Chan et al., 2005). Some companies use the PAMPA as a tier 1 prescreen discovery... 

Due to the fact that the affinity of PE and PP membrane with electrolyte is poor, a lot of researchers are focused on it. Cheng and Sun [57] coat PP membrane (Celgard 2400 single-layer membrane) with PE mixed with nanometer silicon dioxide to improve the wettability of the membrane. Miao et al. [58] coat a three-layer composite microporous membrane (PP/PE/PP) with polyvinylidene fluoride (PVDF) surface processing (Figure 12.18). This technology reduces the membrane thickness and battery volume. 

---