Irritative properties of two clinical potassium chloride formulations on duodenal mucosa of the cat and esophageal mucosa of the opossum.

The local gastrointestinal irritating properties of microencapsulated KCl (M-E), a new and unique form of KCl (8 meq potassium per capsule), were compared with a wax-matrix (W-M) KCl formulation (8 meq potassium per tablet). Normal saline in 0-size gelatin capsules was used as the control substance. The comparisons were made in two animal models that simulate the condition of partial obstruction of the gastrointestinal tract in humans. These models are the duodenum of the cat and the esophagus of the opossum, each with a surgically created partial obstruction. The tissues were exposed to two capsules or tablets of KCl or saline for 4 hr, and the extent of tissue injury assessed by using a rating scale. The irritation caused by M-E was significantly (P less than 0.05) less than that caused by W-M in both the cat and the opossum, and it was not significantly (P greater than 0.05) different from the injury caused by saline in either model. The relative lack of irritation by M-E is probably explained by the fact that there was a significantly (P less than 0.05) greater dispersion of KCl from the M-E capsule than from the W-M tablet.