Preparation and Characterization of the Sulfobutylether-β-Cyclodextrin Inclusion Complex of Amiodarone Hydrochloride with Enhanced Oral Bioavailability in Fasted State

Amiodarone hydrochloride (AMD) is used in the treatment of a wide range of cardiac tachyarrhythmias, including both ventricular fibrillation (VF) and hemodynamically unstable ventricular tachycardia (VT). The objectives of this study were to improve the solubility and bioavailability in fasted state and to reduce the food effect of AMD by producing its inclusion complex with sulfobutylether-β-cyclodextrin (SBE-β-CD). The complex was prepared through a saturated water solution combined with the freeze-drying method and then characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. The solubilities of AMD and its complex were 0.35 and 68.62 mg/mL, respectively, and the value of the inclusion complex was significantly improved by 196-fold compared with the solubility of free AMD. The dissolution of the AMD-SBE-β-CD inclusion complex in four different dissolution media was larger than that of the commercial product. The cumulative dissolution was more than 85% in water, pH 4.5 NaAc-HAC buffer, and pH 1.2 HCl aqueous solution. Moreover, the pharmacokinetic study found that the C _max, AUC_(0-t), and AUC_(0-∞) of the AMI-SBE-β-CD inclusion complex had no significant difference in fasted and fed state, which indicated that the absorption of the AMI-SBE-β-CD inclusion complex in fasted state was increased and not affected by food.

Electrocardiographic abnormalities and uremic cardiomyopathy

BACKGROUND

Progressive renal disease is associated with an increased risk of cardiovascular death, specifically sudden death. We investigated the link between uremic cardiomyopathy, QT interval and dispersal, and arrhythmias (by ambulatory ECG monitoring) in patients at different stages of progressive renal disease.

METHODS

In a cross-sectional study we investigated 296 patients with nondiabetic renal disease (53 transplant recipients, 55 hemodialysis patients, and 188 throughout the range of chronic renal failure). Patients underwent echocardiography, ECG, and ambulatory blood pressure and ECG monitoring.

RESULTS

Left ventricular mass was increased from the earliest stages of renal disease (near-normal renal function), the predominant pattern being eccentric left ventricular hypertrophy (LVH). There was a progressive increase in LVH with loss of renal function, so that more than 80% of patients on renal replacement therapy have LVH, the dominant pattern being concentric LVH. The prevalence of diastolic dysfunction increased in parallel with changes in left ventricular mass but systolic dysfunction and ventricular dilatation did not. Increased QT interval and QT dispersal were associated with poor renal function (maximal in dialysis patients), and were linked to LVH and other echocardiographic abnormalities. Arrhythmias were uncommon on ambulatory recording but were more common with poor renal function, in the presence of uremic cardiomyopathy, and increased QT interval and dispersal.

CONCLUSION

LVH is present from the earliest stages of progressive renal disease. This, and other forms of uremic cardiomyopathy, is linked to increased QT interval and dispersal, and with minor rhythm abnormalities, providing a link with the high risk of sudden death in this population.