Fast and simple preparation of microparticles of KHCO₃ by a freeze-dissolving method with single solvent or additional antisolvent

Microparticles featuring specific attributes are essential for the chemical industries. Microparticles of KHCO3 were prepared by a freeze-dissolving method, with one solvent or with additional antisolvent. Firstly, KHCO3 aqueous solution was dripped into liquid nitrogen to prepare ice spherical particles, and additional antisolvent, ethanol, was used to dissolve the ice scaffolding to isolate the microparticles of KHCO3. In this work we have developed a new freeze-dissolving method with only one solvent, water. After formation of ice particles, a low-temperature saturated aqueous solution of KHCO3 was used to dissolve the ice in frozen spherical particles at low temperature to isolate the microparticles. Both freeze-dissolving methods were 100 times faster and more energy-efficient than the traditional freeze-drying method. The microparticles of KHCO3 obtained by the freeze-drying method and freeze-dissolving with antisolvent and with saturated solution were characterised with SEM and the particle size distributions were compared.</p

Supplementary information files for "Fast and simple preparation of microparticles of KHCO₃ by a freeze-dissolving method with single solvent or additional antisolvent"

Supplementary files for article "Fast and simple preparation of microparticles of KHCO3 by a freeze-dissolving method with single solvent or additional antisolvent"Microparticles featuring specific attributes are essential for the chemical industries. Microparticles of KHCO3 were prepared by a freeze-dissolving method, with one solvent or with additional antisolvent. Firstly, KHCO3 aqueous solution was dripped into liquid nitrogen to prepare ice spherical particles, and additional antisolvent, ethanol, was used to dissolve the ice scaffolding to isolate the microparticles of KHCO3. In this work we have developed a new freeze-dissolving method with only one solvent, water. After formation of ice particles, a low-temperature saturated aqueous solution of KHCO3 was used to dissolve the ice in frozen spherical particles at low temperature to isolate the microparticles. Both freeze-dissolving methods were 100 times faster and more energy-efficient than the traditional freeze-drying method. The microparticles of KHCO3 obtained by the freeze-drying method and freeze-dissolving with antisolvent and with saturated solution were characterised with SEM and the particle size distributions were compared.© The Authors, CC BY 3.0</p

Supplementary information files for " Application of efficient and sustainable freeze-dissolving technology in manufacturing of KHCO3 ultrafine particles"

Supplementary files for article "Application of efficient and sustainable freeze-dissolving technology in manufacturing of KHCO3 ultrafine particles"The development of ultrafine particles provided a new way to solve problems in the fields of energy, environment, and medicine, and had become one of the most promising technologies. Therefore, the application of ultrafine particles required the development of cleaner, greener, and more efficient preparation methods. The new freeze-dissolving technology has been applied in manufacturing of KHCO3 ultrafine particles, with an aqueous solution of 0.02–0.1 g KHCO3/g water. Frozen ice particles were formed after dripping the solution into liquid nitrogen. The antisolvent ethanol was used to dissolve the ice spherical template at a temperature below 273.15 K, and the pre-formed KHCO3 ultrafine particles inside the ice template remained in the ethanol aqueous solution. The ice particles were put into the freeze dryer to isolate the ultrafine KHCO3 particles. Compared with the particles produced with traditional freeze-drying technology, the ultrafine powder/particles produced by the freeze-dissolving technology were smaller with narrower size distribution. The freeze-dissolving technology has demonstrated a much more sustainable and efficient manufacturing process than the traditional freeze-drying process. In addition, the influence of the concentrations of KHCO3 and the sizes of ice particles were investigated with the discussions of mechanisms.©The Authors, CC BY-NC-ND 4.0</p

Application of efficient and sustainable freeze-dissolving technology in manufacturing of KHCO3 ultrafine particles

The development of ultrafine particles provided a new way to solve problems in the fields of energy, environment, and medicine, and had become one of the most promising technologies. Therefore, the application of ultrafine particles required the development of cleaner, greener, and more efficient preparation methods. The new freeze-dissolving technology has been applied in manufacturing of KHCO3 ultrafine particles, with an aqueous solution of 0.02–0.1 g KHCO3/g water. Frozen ice particles were formed after dripping the solution into liquid nitrogen. The antisolvent ethanol was used to dissolve the ice spherical template at a temperature below 273.15 K, and the pre-formed KHCO3 ultrafine particles inside the ice template remained in the ethanol aqueous solution. The ice particles were put into the freeze dryer to isolate the ultrafine KHCO3 particles. Compared with the particles produced with traditional freeze-drying technology, the ultrafine powder/particles produced by the freeze-dissolving technology were smaller with narrower size distribution. The freeze-dissolving technology has demonstrated a much more sustainable and efficient manufacturing process than the traditional freeze-drying process. In addition, the influence of the concentrations of KHCO3 and the sizes of ice particles were investigated with the discussions of mechanisms.</p

Rapid and sustainable production of nano and micro medicine crystals via freeze-dissolving technology

Modern pharmaceutical manufacturing emphasizes the need for sustainable technologies. Fine particles, including nano and micro-sized crystals, are increasingly important, particularly in the production of inhalation medicines. A novel application of freeze-dissolving technology has been demonstrated in the production of metronidazole, a model drug. This process involves creating frozen spherical particles by introducing a tert-butanol solution containing dissolved metronidazole into liquid nitrogen. Various antisolvents, such as n-hexane, n-heptane, ethanol, n-propanol, n-butanol, or n-pentanol, were employed to dissolve these frozen templates at temperatures ranging from 248.15 to 278.15 K. During this process, pre-formed metronidazole fine particles within the frozen template were released into the antisolvent solution. An alternative method involved placing these frozen particles into a vacuumed freeze dryer to extract the fine particles. The new freeze-dissolving technology can save 99% both energy and time compared to the traditional freeze-drying method, demonstrating a significantly more efficient and sustainable pharmaceutical manufacturing approach.</p