Gastrointestinal absorption of sfericase

The gastrointestinal absorption of sfericase was determined using rabbits. Serum sfericase level was measured by ATNE of a specific substrate. The addition of anti-sfericase antibody resulted in pronounced decrease in ATNE-hydrolyzing activity of sfericase, so that the hydrolyzing activity in serum was confirmed to be due to sfericase. Although a great individual difference was observed, the absorption rates of sfericase following intraduodenal administration of sfericase powder at dosages of 10 mg/kg (n = 4), 20 mg/kg (n = 4), and 100 mg/kg (n = 1) dissolved in physiologic saline were 0.380%, 0.267%, and 0.706%, respectively. When a single dose of sfericase enteric granules (sfericase content was 36.8%) was given orally at dosages of 250 mg, 500 mg, and 1 g (two animals were used for each dose level), a measurable amount of sfericase appeared in the serum 0.5-1 h after administration. The same enteric granules were given at a dosage of 1 g/animal/day for 10 days or at 250 mg/animal/day for 20 days continuously to determine changes in the gastrointestinal absorption rate. Continued administration of sfericase had no influence on its gastrointestinal absorption.