Cocrystals Enhance Biopharmaceutical and Antimicrobial Properties of Norfloxacin

Abstract

A solvate cocrystal of the antimicrobial norfloxacin (NFX) was formed by using isonicotinamide (INA) as a coformer with the solvent evaporation technique. The cocrystal formation was confirmed by performing solid-state characterization techniques. We evaluated the dissolution under supersaturated conditions and also the solubility at the vertex of triphasic domain of cocrystal and NFX in both water and Fasted-State Simulated Intestinal Fluid (FaSSIF). The antimicrobial activity was evaluated using the microdilution technique. The cocrystal showed 1.8 times higher dissolution than NFX in water at 60 min and 1.3 times higher in FaSSIF at 180 min in the kinetic study. The cocrystal also had an increase in solubility of 8.38 times in water and 6.41 times in FaSSIF. The biopharmaceutical properties of NFX with cocrystallization improved antimicrobial action, as shown in the results of minimum inhibitory concentration (MIC) and inhibitory concentrations of 50% (IC50%) and 90% (IC90%). This paper presents, for the first time, a more in-depth analysis of the cocrystal of NFX–INA concerning its dissolution, solubility, and antimicrobial activity. In all these criteria, the cocrystal obtained better results compared to the pure drug.

Unraveling a Unique Metastable Phase of a Proxyphylline Cocrystal Exclusively Produced by Compressed Carbon Dioxide

“…Beyond the fact that cocrystals are solid forms different from the solid reactants they originate, literature also lately reported several examples of polymorphic cocrystals − and solvate cocrystals. − These are mostly produced by conventional methods. Though the potentiality of scCO 2 -based techniques to control polymorphism has been addressed for homocrystals, − only few articles reported polymorphism of cocrystals, , one for the production of a solvate, and none has ever reported the obtention of a cocrystal solvate.…”