This invention discloses a low-temperature
chelation preparation method for high-purity
ferrous citrate with
antioxidant properties, belonging to the field of pharmaceutical
raw material preparation technology. Addressing the shortcomings of existing
ferrous citrate preparation processes, such as easy oxidation of
ferrous iron, severe secondary oxidation during
drying, and the inability to simultaneously achieve high purity and long-term
antioxidant effects, this invention employs a segmented gradient low-temperature
chelation process to prepare high-purity
ferrous citrate wet crystals. It deeply couples
trehalose glassy embedding with a low-temperature
oxygen-free closed-loop gradient
drying process. In the two-step
drying process of vacuum pre-freezing
dehydration at -5-0℃ and
oxygen-free
nitrogen closed-loop drying at 15-20℃, deep
dehydration of the product, in-situ formation of a monomolecular
citric acid passivation film on the
crystal surface, and dense formation of a
trehalose amorphous glassy film are simultaneously achieved. This constructs a dual-layer synergistic
protection system with an inner layer of chemical
passivation and an outer layer of
physical barrier. This invention introduces no exogenous antioxidants throughout the entire process, and the prepared
ferrous citrate has a purity ≥99.5%, possessing high purity, strong
antioxidant properties, and excellent rehydration properties, making it suitable for a wide range of applications.