Novel Orally Swallowable IntelliCap® Device to Quantify Regional Drug Absorption in Human GI Tract Using Diltiazem as Model Drug

Typically, colonic absorption of a drug is mandatory for a sustained release formulation to hold the drug's plasma level for more than 12 or 24 h above the minimum therapeutic plasma concentration (efficacy). According to Drugs@FDA, only 7.4% of the oral drugs are extended release forms probably showing colonic absorption. Therefore an early determination of a drug's colonic absorption using the IntelliCap (R) in animals or humans will provide the mandatory information to initiate or stop a SR form development. Diltiazem (60 mg) is used in the oral swallowable IntelliCap (R) and the marketed SR form from Mylan (coated beads). A human study with 14 healthy volunteers compared the Mylan formulation with the IntelliCap (R) device that releases the drug identical to the in-vitro dissolution of the Mylan product. The plasma profiles of IntelliCap (R) and Mylan formulation are highly similar. The mean AUC (bioequivalence fulfilled) and mean Cmax of IntelliCap (R) shows only a difference of +15% and -12%, respectively. But the PK profile of the Mylan formulation shows a broader peak around Cmax. About 81.8% diltiazem was absorbed in the colon (IntelliCap (R)) comparable to former publications. The Mylan is a SR diffusion coated beads form whereas the IntelliCap (R) is a monolithic capsule. The beads are transported in the gut and spread which results in a longer Tmax and a broader Cmax peak. The IntelliCap (R) device can quantitatively measure the colonic absorption of a drug in excellent accordance to a standard oral SR dosage form.