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

ABSTRACT. 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 concentra-tion (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 ® 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 ® and the marketed SR form from Mylan (coated beads). A human study with 14 healthy volunteers compared the Mylan formulation with the IntelliCap ® device that releases the drug identical to the in-vitro dissolution of the Mylan product. The plasma profiles of IntelliCap ® and Mylan formulation are highly similar. The mean AUC (bioequivalence fulfilled) and mean Cmax of IntelliCap ® 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®) comparable to former publications. The Mylan is a SR diffusion coated beads form whereas the IntelliCap ® 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 ® device can quantitatively measure the colonic absorption of a drug in excellent accordance to a standard oral SR dosage form. KEY WORDS: device; diltiazem; human study; intelliCap; regional absorption