Abstract
The aim of this research was to increase the oral bioavailability of daidzein by the formulations of poly(lactic-co-glycolic) acid (PLGA) nanoparticles loaded with daidzein. Amongst the various traditional and novel techniques of preparing daidzein-loaded PLGA nanoparticles, daidzein-loaded phospholipid complexes PLGA nanoparticles and daidzein-loaded cyclodextrin inclusion complexes PLGA nanoparticles were selected. The average drug entrapment efficiency, particle size, and zeta potential of daidzein-loaded phospholipid complexes PLGA nanoparticles and daidzein-loaded cyclodextrin inclusion complexes PLGA nanoparticles were 81.9% ± 5%, 309.2 ± 14.0 nm, -32.14 ± 2.53 mV and 83.2% ± 7.2%, 323.2 ± 4.8 nm, -18.73 ± 1.68 mV, respectively. The morphological characterization of nanoparticles was observed with scanning electron microscopy by stereological method and the physicochemical state of nanoparticles was valued by differential scanning calorimetry. The in vitro drug-release profile of both nanoparticle formulations fitted the Weibull dynamic equation. Pharmacokinetic studies demonstrated that after oral administration of daidzein-loaded phospholipid complexes PLGA nanoparticles and daidzein-loaded cyclodextrin inclusion complexes PLGA nanoparticles to rats at a dose of 10 mg/kg, relative bioavailability was enhanced about 5.57- and 8.85-fold, respectively, compared to daidzein suspension as control. These results describe an effective strategy for oral delivery of daidzein-loaded PLGA nanoparticles and might provide a fresh approach to enhancing the bioavailability of drugs with poor lipophilic and poor hydrophilic properties.