This study aimed to design an effective nanoparticle-based carrier for the oral delivery of fisetin (FST) with improved biopharmaceutical properties. FST-loaded nanoparticles were prepared with polyvinyl alcohol (PVA) and poly(lactic-co-glycolic acid) (PLGA) by the interfacial deposition method. A central composite design of two independent variables, the concentration of PVA and the amount of PLGA, was applied for the optimization of the preparative parameter. The responses, including average particle size, polydispersity index, encapsulation efficiency, and zeta potential, were assessed. The optimized formulation possessed a mean particle size of 187.9 nm, the polydispersity index of 0.121, encapsulation efficiency of 79.3%, and zeta potential of −29.2 mV. The morphological observation demonstrated a globular shape for particles. Differential scanning calorimetry and powder X-ray diffraction studies confirmed that the encapsulated FST was presented as the amorphous state. The dissolution test indicated a 3.06-fold increase for the accumulating concentrations, and the everted gut sac test showed a 4.9-fold gain for permeability at the duodenum region. In conclusion, the optimized FST-loaded nanoparticle formulation in this work can be developed as an efficient oral delivery system of FST to improve its biopharmaceutic properties.

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The purpose of this study is to prepare lemon essential oil (LEO) microcapsules by ionic gelation method using chitosan (CS) and cellulose nanocrystals (CNC) as the wall material. The influence of the concentration of CS and CNC and the pH of CS solution on the encapsulation efficiency (EE) of microcapsules was studied. Taking the EE as an indicator, and according to the single‐factor test results, a three‐factor three‐level response surface methodology was designed. The best process conditions of CS/CNC‐LEO microcapsules to get the maximum EE of 89.98% were as follows: pH of CS was 3.44, and the concentration of CS, CNC were 2, 3.52 g/L. The microcapsules prepared under these conditions were smooth and rounded spherical. The diameters of unembedded and embedded LEO microcapsules ranged from 541.2–732.9 to 1014.5–1528.7 nm, respectively. Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis were used to analyze the characteristics of the microcapsules. There were two periods in vitro release studies of CS/CNC‐LEO microcapsules: sudden release and slow release of essential oils.

Higenamine is a β2‐agonist that has been prohibited in sports by the World Anti‐Doping Agency. Higenamine could potentially promote anabolism and lipolysis; however, its crucial pharmacokinetics data, particularly muscle distribution, remain unavailable. The present study aims to investigate the blood‐to‐muscle distribution as well as the urinary excretion of higenamine in laboratory rats. In the first experiment, the microdialysis technique was employed to continuously measure free, protein‐unbound concentrations in blood and muscle for 90 min (sampling at a 5‐min interval) after rats received IV infusion of higenamine. The mean half‐lives of higenamine in blood and muscle were 17.9 and 19.0 min, respectively. The blood‐to‐muscle distribution ratio (AUCmuscle/AUCblood) of higenamine was estimated to be 22%. In the second experiment, rats were orally administered with a single‐dose higenamine, and their urine samples were profiled at a 12‐h interval for up to 48 h. Results showed only a small portion of total consumption (1.44%, ranging 0.71%–2.50%) was excreted in the urine. Among these time points, about 43% cumulative amount of higenamine was eliminated within the first 12 h. Our data suggested that one‐quarter of the unbound higenamine rapidly penetrates from the vessels into muscle, distributes to the interstitial fluid, then eliminates from the rat in a short span of time. The muscle tissue is likely to have a low binding affinity for higenamine, and renal excretion plays a minor role in its elimination. Together, our findings provide valuable pharmacokinetics data that may gain deeper insights into higenamine's role in skeletal muscle functions.

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