Enhancing oral bioavailability using preparations of apigenin-loaded W/O/W emulsions: In vitro and in vivo evaluations.

We analyzed the physical properties and digestibility of apigenin-loaded emulsions as they passed through a simulated digestion model. As the emulsion passed through the simulated stages of digestion, the particle size and zeta potential of all the samples changed, except for the soybean oil-Tween 80 emulsion, in which zeta potential remained constant, through all stages, indicating that soybean oil-Tween 80 emulsions may have an effect on stability during all stages of digestion. Fluorescence microscopy was used to observe the morphology of the emulsions at each step. The in vivo pharmacokinetics revealed that apigenin-loaded soybean oil-Tween 80 emulsions had a higher oral bioavailability than did the orally administrated apigenin suspensions. These results suggest that W/O/W multiple emulsions formulated with soybean oil and tween 80 have great potential as targeted delivery systems for apigenin, and may enhance in vitro and in vivo bioavailability when they pass through the digestive tract.

Preparation of chitosan-TPP microspheres as resveratrol carriers.

Resveratrol (3,4',5-trihydroxy-trans-stilbene)-loaded chitosan-sodium tripolyphosphate (TPP) microspheres using high (310 to 375 kDa) and medium (190 to 310 kDa) molecular weight chitosan and TPP in varying concentrations were produced to improve resveratrol bioavailability. A 450 µm nozzle encapsulator was used to produce the microspheres. The mean microsphere particle size was between 160 and 206 µm, and exhibited a narrower size distribution as the TPP solution concentration increased. The encapsulation efficiency increased from 94% to 99% with a decrease in chitosan concentration from 1% to 0.5% and a decrease in crystallinity of the microspheres. FTIR data showed a polyelectrolyte interaction between chitosan and TPP. X-ray diffraction patterns were matched up with DSC and FTIR, which shows decrease of crystallinity and enhancement of hydrogen bonding with TPP concentration. An increase in the concentration of TPP solution from 1% to 3% led to a lower initial burst of resveratrol release. These results suggest that chitosan-TPP microspheres could be used as a potential delivery system to control the release of resveratrol.

Reduction in fat uptake of doughnut by microparticulated wheat bran.

Wheat flour-microparticulated wheat bran (MWB) mixture and composites were prepared, and their potential as an oil repellent was evaluated in doughnuts. As MWB content increased, the oil-holding capacity decreased, and there were significant changes in water-holding capacity (p < 0.05). As MWB content increased, the fat content of doughnuts decreased. In addition, the wheat flour-MWB composite was more effective for preventing fat uptake than the wheat flour-MWB mixture. The hardness of the composite was higher than the mixture, although volume and weight decreased and surface colour became darker than that of the mixture. As the proportion of wheat bran in the doughnut formulation increased, the inner crust achieved a uniform cell size and cellular integrity was improved. Based on these data, wheat flour-MWB composites are appropriate for use in doughnut formulas with low fat uptake.