The mean biovailability(F) after s.c. injection of rHuEPO was signincantly higher than that after i.p. injection in healthy SD rats. The mean t1/2β after a s.c.dose of 100U/kg in normal human volunteers
pre-dialysis and peritoneal dialysis uremic patients were 15.4 ± 0.9
16.6 ± 6.9 and 9.2 ± 2.7 h respectively. In pre-dialysis patients
the mean F after a s.c. dose was 41 ± 17%. Serum rHuEPO concentrations after a s.c. dose decreased slowly and were over three times of baseline 48 hours later. It is concluded that s.c. administration is the optical route for rHuEPO.