An orally administered microcapsule system for treating chronic renal failure patients

Abstract

Ingestible adsorbents for the removal of uremic metabolites are being investigated as adjunctive therapy in the treatment of chronic uremia. In particular, a microcapsule product containing urease and zirconium phosphate (UZP) has been investigated for removing urea. A dog model, simulating chronic uremia, was developed to investigate: (1) the concentration of various nitrogenous metabolites (urea, creatinine, and uric acid) in the GI tract, (2) flux rates of H2O and various nitrogenous metabolites in the GI tract, and (3) the efficacy of the microcapsule product. The results of these perfusion studies suggest that urea and creatinine can be removed from the GI tract via ingestible adsorbents. In addition, the model may be useful in investigating suspect uremic toxins, e.g., guanidinosuccinic acid (GSA). The reduction of blood urea nitrogen levels in the dog model when the animal was fed the microcapsule product was limited by the capacity of the zirconium phosphate to bind ammonium ion. Preliminary clinical studies with the microcapsule product indicate that it may be of potential adjunctive therapy in patients suffering from chronic renal failure.

Potentials and limitations of microorganisms as renal failure biotherapeutics

“…26 and also markedly small amount of urea removal have been reported in vivo, particularly at a neutral pH. 6,13,15,19,23,[27][28][29][30] In another approach, a microencapsulated multienzyme system that converts urea and ammonia into essential amino acids was investigated. 13,18,19,28 However, this encapsulated multienzyme system had an inadequate urea and ammonia conversion rate.…”