Co-amorphous, a novel approach to improve some pharmaceutical properties of drug products, have been increasingly recognized as a new formulation where the amorphous drug is stabilized through strong intermolecular interactions by a co-former.
In this work, syntheses and characterization of Metronidazole and 4-Hydroxybenzoic Acid (MTZ+HBA) co-crystal are firstly conducted. The physical state of co-crystal was characterized by PXRD, DSC, and FTIR. The DSC thermogram for (MTZ+4AHB) in Figure 1 showed a single endothermic transition attributed to the melting transition at 119°C. The thermal behavior of the co-crystal was distinct, with a different melting transition from that seen with either of the individual components; this suggests the formation of a new phase: (MTZ+4AHB) co-crystal. The glass transition temperature (Tg) appeared at 38°C after the second heatins of the product.