We evaluated three
acid-resistant pancreatic
enzyme preparations by in vitro assays, and by comparing degree of
steatorrhea, creatorrhea, fecal wet weight, and stool energy losses in a randomized crossover study of patients with pancreatic insufficient
cystic fibrosis. Aims of the study were to assess (a) the most practicable and reliable
indicator of malabsorption; (b) the variation in
enzyme batch potency; (c) the decline in
enzyme batch potency with prolonged shelf life; and (d) the relative bioefficacy of the different preparations. In the in vivo study, absorption of energy,
nitrogen, and fat did not differ when comparing the three preparations at roughly pharmaceutically equivalent doses, but when expressed per
capsule of pancreatic supplement ingested, absorption reflected relative
enzyme content, favoring the higher potency preparations. Although
steatorrhea was reasonably controlled by these preparations, stool energy losses varied from 800 to 1,100 kJ per day, suggesting greater attention be paid to overall energy absorption rather than absorption of individual nutrients. In addition, fecal energy loss correlated more closely with fecal wet weight (r = 0.81; p < 0.05) than with
steatorrhea (r = 0.40; ns), such that 1 g wet feces = 8.37 kJ (+/- 0.14). In vitro
enzyme potency varied markedly between batches of the same brand, and also a decline of up to 20% in
amylase,
lipase, and
trypsin activity was noted over an 8-month period for each batch. Both observations have clinical implications at times of represcription. Finally, the higher potency preparations were more effective per
capsule and reduced
capsule dosage is therefore attainable.