Microparticle (MP) released from a DALI 750 Adsorber column for low density lipoprotein apheresis, which is used in a direct hemoperfusion system, was evaluated. The numbers of MP were measured by a light blockage method in the effluents from the column during the rinsing (priming) procedure using a priming solution, and the simulated treatment procedure using a physiologic saline solution as a substitute for whole blood. An unacceptable number of MP were released from the column during the simulated treatment after rinsing with an amount of solution prescribed by the manufacturer. MP concentrations (mean values of three experiments) in the initial 300 ml of the effluent were 639.9, 75.1, and 3.6 pieces/ ml for ≥5 µm, ≥10 µm, and ≥25 µm, respectively, and neither the result for ≥5 µm nor for ≥10 µm meets the requirement for solutions for injection defined in the United States Pharmacopoeia XXIII or the British Pharmacopoeia of 1993. Furthermore, a large number of MP still remained in the column after all the simulated operations. These findings suggest that the column has a potential to release an unacceptable number of MP into the patient during treatment. Further investigation on the influence of the MP released into the patient's circulation is necessary.
Copyright © 1998 by the American Society for Artificial Internal Organs