Dialysis membranes drug removal

Figure 1. Mechanisms by which drugs are removed by dialysis (indicated by dialysate) or sorbent hemoperfusion. The pore structure of dialysis membranes and sorbents is the major determinant of chemical/drug size selection.

Hemodialysis The process by which a drug is removed from the blood of a poisoned patient by allowing it to diffuse across a semipermeable membrane while the blood is pumped through a dialysis machine. 

Dialysis is considered the reference method when studying protein binding of drugs (45) but is also useful for protein removal prior to plasma analysis. Dialysis is a classical separation method that uses semipermeable membranes to separate compounds by molecular weight. The protein sample is exposed to a buffer solution separated by the membrane. After the system is allowed to come to equilibrium, the small molecules diffuse to similar concentrations on both sides, while the sample side contains all of the protein... 

ABSORPTION, DISTRIBUTION, FATE, AND EXCRETION Some antipsychotic drugs have erratic and unpredictable patterns of absorption after oral administration. Parenteral (intramuscular) administration increases the bioavaftabUity of active drug 4-10-fold. Most antipsychotic drugs are highly lipophilic, highly membrane- or protein-bound, and accumulate in the brain, lung, and other tissues with a rich blood supply. They also enter the fetal circulation and breast milk. It is virtually impossible to remove these agents by dialysis. 

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