Zein Beta-Cyclodextrin Micropowders for Iron Bisglycinate Delivery

Given the limited number of materials available to design delivery platforms for nutrients,the rational combination of raw materials already approved as food ingredients and their processingthrough nano-micro technology can offer a unique tool for innovation. Here,we propose a nano-in-microstrategy to produce powders based on the hydrophobic protein zein, useful for the oral delivery ofa hydrophilic iron source (iron bisglycinate) in anaemic patients. Iron-loaded powders were preparedthrough a two-step strategy consisting in the formation of a zein pseudolatex followed by a spray-dryingstep. To extend the manipulation space for zein and entrap iron bisglycinate, -cyclodextrin (CD) wasselected as helping excipient. Addition of CD allowed iron loading in the pseudolatex and greatlyincreased product yields after the drying process as compared to zein alone. Iron-loaded micro-sizedpowders were characterised by attenuated total reflectance-Fourier transform infrared (ATR-FTIR)spectra, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to elucidate therole of CD as a compatibilizer for the zein-iron system. Remarkably, micropowders released only20% of FeBIS in a simulated gastric fluid, whereas release in a simulated intestinal fluid was almostcompleted in 7 h. In summary, CD association to zein is a novel strategy to expand applications in theoral delivery of iron bisglycinate and, prospectively, to micronutrient chelates.