Activated carbons for medical applications. In vitro microparticle characterization and solute adsorption

Activated carbon is a high surface area adsorbent. Its ability to adsorb nitrogenous metabolic wastes and exogenous poisons from blood has been well documented. Polymeric coatings on activated carbon enhance its biotolerability and make it feasible for use in hemoperfusion devices. The only drawback seems to be the presence of microparticles on the carbon surface. These particles may become emboli during hemoperfusion. This paper describes a series of in vitro tests used to evaluate many commercially available granular and pelletized activated carbons. The tests were as follows: 1) creatinine adsorption capacity and kinetics, 2) initial cleanliness, 3) washability, 4) attrition resistance, and 5) carbon particle surface morphologymone grade of activated carbon has been chosen for hemoperfusion studies on the basis of the above evaluations; The nature of the microparticles and the approach used to remove them from this carbon is described.