Development and in vitro characterization of a novel prenatal multi‐micronutrient powder incorporating differentially microencapsulated calcium carbonate and ferrous fumarate to overcome intra‐intestinal calcium‐iron interactions

Abstract

To overcome calcium(Ca)‐iron(Fe) interactions in a prenatal multi‐micronutrient supplement for low‐income settings, we developed a Ca‐Fe‐folic acid (FA) powder for home fortification incorporating enteric coatings sensitive to low pH (for gastric Fe release) and high pH (for mid‐duodenal Ca release). Ca carbonate and ferrous fumarate granules were generated by wet granulation. A fluid‐bed coating process was used to apply subcoat to the Ca granules to improve sphericity and to apply a pH‐sensitive enteric coat. Fe granules were encapsulated with a time‐dependent coating, including FA in the matrix. Fe and Ca dissolution profiles were assessed during sequential exposure to acidic (pH 1.2, 120 min) and basic (pH 5.8, 100 min) media using a modified USP methodology. At pH 1.2, Ca release was 15% after 120 min; Fe release was 90% and 100% at 20 and 35 min, respectively. After 100 min at pH 5.8, 85% of total Ca was released. These dissolution profiles indicated that the differential release of Ca and Fe was achieved within targeted acid‐base environments. Clinical testing to document fractional Ca absorption during pregnancy is underway. Research support was provided by the Saving Lives at Birth partners.Grant Funding Source: Saving Lives at Birth