Safety, heart specificity, and therapeutic effect evaluation of Guanfu base A-loaded solid nanolipids in treating arrhythmia.

Guanfu base A·HCl (GFA·HCl) solution, approved by the China Food and Drug Administration (CFDA) in 2005, has been used in the treatment of arrhythmia. However, the poor targeting and absorption of GFA·HCl have severely affected its clinical application. In this study, a nanolipid-based, Guanfu base A (GFA) delivery system was designed to improve the deficiency of GFA·HCl and realize better clinical effect. The GFA-loaded solid nanolipids (GFASN) with a core/shell structure, composed of Poloxamer 188, lecithin, and medium-chain fatty acid, were prepared using a high-pressure homogenate emulsification method. Results showed that GFASN possessed well morphology and stability during the process of lyophilization and rehydration at 220-260 nm. Safety evaluation revealed that ear vein injection of GFASN (14 mg/kg) were safe enough and of good biocompatibility. More importantly, GFASN can better alleviate the arrhythmia of rats, especially in ventricular ectopia and ventricular tachycardia, than GFA·HCl solution. Pharmacokinetic behaviors and targeting evaluation in mice demonstrated that nanolipids can help GFA achieve longer circulation time in blood and better heart specificity. Collectively, these promising findings suggested that this kind of nanolipids was an ideal delivery carrier for GFA in the treatment of cardiovascular disease.