While all the OTC and Rx pancrealipase are sourced from porcine pancreas, the Rx brands use enteric coatings to control the time release of the microspheres of the amylase, lipase and protease. This is how the capsule contents provides coverage over 45 minutes. Non-enteric coated enzyme brands get activated immediately upon reaching the alkaline pH of the intestine and lose their activity after 15 minutes.

As was already pointed out in another post of this thread, manufactures use different units for reporting the enzyme concentration of lipase. The Rx brands tend to have a higher lipase concentration than the OTC counterpart.

Another difference is in order to have FDA approval, the Rx brands must meet or exceed rigid quality control standards including adhering to a tighter tolerance in variability of enzyme activity published on the label. Variation from what is published must be within +/- 10%. This adds manufacturing costs for adhering to FDA manufacturing guidelines.

The variability is a much wider range in OTC brands. This would be important with infants and adults following a limited, consistent diet where dosing is more critical.