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Freeze‐drying of ceftriaxone sodium solution frozen with prefabricated porosity
Author(s) -
Wang Wei,
Hu Dapeng,
Pan Yanqiu,
Li Hengle,
Chen Guohua
Publication year - 2019
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23232
Subject(s) - freeze drying , porosity , liquid nitrogen , compaction , materials science , saturation (graph theory) , composite material , aqueous solution , chemistry , chemical engineering , chromatography , organic chemistry , mathematics , combinatorics , engineering
Initially unsaturated material frozen with prefabricated porosity was prepared to experimentally investigate its effect on freeze‐drying of liquid material. Ceftriaxone sodium, a kind of commonly used antibiotic, was selected as the primary solute in an aqueous solution. The liquid nitrogen ice cream‐making method was employed to prepare frozen materials with different initial porosities. Results showed that freeze‐drying was significantly enhanced with the initially unsaturated frozen material and substantial drying time was saved compared with conventional freeze‐drying. Drying time for the unsaturated sample (0.3 of saturation or 0.67 of initial porosity) was more than 20 % shorter than that required for the saturated one (1.0 of saturation without initial porosity). SEM images displayed that the dried products of the unsaturated frozen material had a pierced solid skeleton and uniform pore space with a fine and tenuous structure compared with those of the saturated one. The freezing rate exhibited little influence on the freeze‐drying process. Annealing can be moderately beneficial to shortening the drying time and further improving the energy utilization. An appropriate increase in operating temperature was able to enhance the freeze‐drying rate while changes in chamber pressure had a negligible effect on the process.