Pancrease gastroresistance: in vitro evaluation of pH-determined dissolution.

In order to avoid inactivation in the stomach, pancreatic enzymes have been prepared as pH-sensitive, enteric-coated microspheres (Pancrease). An in vitro study was performed to evaluate the pH-related dissolution of Pancrease and to confirm its resistance to gastric acidity. Two assay methods were used with three different batches of Pancrease: (a) Enzyme absorbency at 280 nm was measured at unit pH intervals from pH 1 to pH 8 and at 0.5 pH intervals from the start of dissolution to pH 8. (b) Proteolytic activity was measured at pH 6.8. Significant enzyme dissolution started at pH 5.5 and was maximal at pH 6.0. At pH 6.8, the pH of simulated intestinal fluid, dissolution was complete in less than 15 min. At pH 5.0, no dissolution occurred within the first 10 min and only 13% dissolution was observed after 2 h. At pH 7.0, 100% dissolution was seen within 10 min. Results of the two assay methods were comparable with all three enzyme batches assayed. This study confirmed the gastroresistance of Pancrease. Because of the enteric coating of Pancrease, liberation of enzymes occurs in the duodenum and jejunum, providing maximal enzymatic efficacy in exocrine pancreatic insufficiency.