Physico-chemical study of norfloxacin and metronidazole binary mixtures

作者：Salceanu Daniela Crina; Pincu Elena; Bruni Giovanna; Marini Amedeo; Meltzer Viorica^*

来源：Journal of Thermal Analysis and Calorimetry, 2018, 132(2): 1095-1103.

DOI：10.1007/s10973-017-6919-7

• Norfloxacin
• Metronidazole
• Phase equilibrium
• Eutectic
• Combined medicine

The physico-chemical characterization of norfloxacin commercial sample (NF), norfloxacin anhydrous form A (NFanhA), norfloxacin pentahydrate (NF center dot 5H(2)O) and metronidazole (MZ) has been carried out. It was determined that the commercial sample is a mixture of 74% anhydrous NF form A and 26% hemipentahydrate NF. From XRPD analysis, it was observed that after the water loss, NF center dot 5H(2)O undergoes a solid-solid transition and is converting to NFanhA. Solid-liquid equilibrium for NFanhA-MZ and NF center dot 5H(2)O-MZ binary systems has been investigated using differential scanning calorimetry, and simple eutectic point was observed, in good approximation, at 419 K for all the mixtures studied. The experimental solid-liquid phase diagram was compared with predictions obtained from available eutectic equilibrium models. The results indicate non-ideality for the mixture. The mixing enthalpy was determined at the eutectic composition and the negative value obtained, Delta(M) H = - 13.28 kJ mol(-1), indicates that molecules of the two components form clusters in the eutectic melt.

• 出版日期2018-5