Pharmacokinetic and pharmacodynamic evaluation of nano-fixed dose combination for hypertension.

The current study was planned to formulate, characterize and evaluate the pharmacokinetics, and pharmacodynamics of a novel 'NanoFDC' comprising hydrochlorothiazide, candesartan (CNDT) and amlodipine. The candidate drugs were loaded in poly(DL-lactide-co-glycolide) by emulsion-diffusion-evaporation method. The formulations were evaluated for their size, morphology, drug loading and in-vitro release individually. Repeat dose pharmacokinetic and pharmacodynamic study of the nano-fixed dose combination (FDC) was done in dexamethasone-induced animal model. The entrapment efficiencies ranged from 44 ± 2.1, 32.2 ± 4 and 40.5 ± 2.6% for amlodipine, hydrochlorothiazide and CNDT, respectively. The nanoparticles ranged in size from 164 to 215 nm. In-vitro release profile of the nanoformulation showed unto 90% release by day 7 in simulated gastric fluid and simulated intestinal fluid, respectively. In pharmacokinetic analysis a sustained-release for 7 days was observed in nano-FDC group. Once weekly oral dosing of nano-FDC of amlodipine, CNDT and hydrochlorothiazide provided adequate antihypertensive effect which was not statistically different from daily dosing of free drugs in dexamethasone-induced animal model. Once weekly oral dosing of nano-FDC of amlodipine, CNDT and hydrochlorothiazide provided adequate antihypertensive effect and was not statistically different from daily dosing of free drugs in dexamethasone-induced animal model. This study provides proof of concept of feasibility of once weekly dosing of a nano-FDC comprising three antihypertensive drugs, which can lead to significant improvement in patient adherence to therapy.