Diltiazem hydrochloride, a non-dihydropyridine derivative, is a member of the group of drugs known as benzothiazepines, which are a class of calcium channel blockers, used in the treatment of hypertension, angina pectoris and hypertension. some types of arrhythmia. It is a class III antianginal drug and a class IV antiarrhythmic [1]. Diltiazem hydrochloride exerts its pharmacological action by inhibiting the transmembrane influx of extracellular calcium ions across the membranes of myocardial cells and vascular smooth muscle cells, without changing serum calcium concentrations. It is a peripheral arterial vasodilator that acts directly on vascular smooth muscle causing a reduction in peripheral vascular resistance and blood pressure. It has substantial inhibitory effects on the cardiac conduction system, acting primarily on the atrioventricular (AV) node to slow conduction time and prolong AV nodal refractoriness. Although it is a cornerstone in the treatment and management of hypertension, angina, and arrhythmia, it presents a serious pharmacokinetic problem. Despite the fact that fol...