Gel–Crystal Transition during Crystallization of Cefpiramide

The gel-crystal transition during crystallization of Cefpiramide was systematically investigated for the first time in this letter. The results show that gelation is a metastable state, it comes from the three-dimensional mesh self-assembly structure made by carbonyl group, amide group and carboxyl group through hydrogen bonding interaction. After that, the gelator assembles to the crystals slowly, the equilibrium of gelation is broken up, the gel will return to the crystal finally.