Figure 4. Removal of protein-bound toxins as a function of membrane permeability taken from multiple studies²⁰,²⁶,³⁰,³¹,³².

Ultrafiltration coefficients represent the type of membrane used in the studies. Some studies³⁰ used different membranes to evaluate the influence of ultrafiltration coefficient on the PBUT removal. Others³² used same membranes under the varying conditions, such as 4 and 8 hours of dialysis treatment.