摘要
Unlike the adverse eff ect caused by the gelation during crystallization process, gelation of cefpiramide sodium was found to provide ideal product properties, such as a larger and more regular crystal shape. The causes of the gelation phenomenon and the mechanism of gel-crystal transition during the crystallization of cefpiramide sodium were both investigated in this work. The gel was formed due to the strapping of the solvents by the networks of cefpiramide sodium molecules. The whole gel-crystal transition process was divided into the following three stages:(1) when the temperature decreased, the system reached a metastable-state gelation;(2) the initial microcrystal in the gel grew slowly because of the low supersaturation;and (3) the gel fi nally disappeared, and a larger and more regular crystal was formed. The Hansen solubility parameters were used to analyze the eff ects of the solvents on this gelation;the analysis results can serve as guidance for solvent screening in the actual production process.
Unlike the adverse effect caused by the gelation during crystallization process, gelation of cefpiramide sodium was found to provide ideal product properties, such as a larger and more regular crystal shape. The causes of the gelation phenomenon and the mechanism of gel–crystal transition during the crystallization of cefpiramide sodium were both investigated in this work. The gel was formed due to the strapping of the solvents by the networks of cefpiramide sodium molecules. The whole gel–crystal transition process was divided into the following three stages:(1) when the temperature decreased, the system reached a metastable-state gelation;(2) the initial microcrystal in the gel grew slowly because of the low supersaturation; and(3) the gel finally disappeared, and a larger and more regular crystal was formed. The Hansen solubility parameters were used to analyze the effects of the solvents on this gelation; the analysis results can serve as guidance for solvent screening in the actual production process.
基金
supported by Tianjin Municipal Natural Science Foundation (No. 16JCZDJC32700)
Major National Scientifi c Instrument Development Project (No. 21527812)
