Structural and biopharmaceutical evaluation of newly synthesized norfloxacin co-crystals using crystal engineering approach

Abstract

The study aims to enhance the biopharmaceutical properties of norfloxacin, a water-insoluble antibacterial antibiotic by synthesizing its co-crystals. Co-crystallization technique resulted in the formation of three co-crystals (NF-NIC, NF-CIN, and NF-SA using three co-formers: nicotinamide, cinnamic acid, and sorbic acid, and employing liquid-assisted grinding approach. Newly prepared co-crystals were characterised using different analytical techniques and crystalline identity was revealed by the PXRD studies, which were further used to determine the crystal structure using Material studio Software. Co-crystals were sustained by hydroxyl-‑carbonyl, amide–carbonyl, and amide‑hydroxyl hydrogen bond network. Novel solid forms were assessed for their physicochemical properties, pharmacokinetics parameters and in vitro antimicrobial activity. Present study provided us with NF in co crystalline forms with significant improvement in the solubility (8 to 3-fold) and dissolution (6 to 2-fold) with simultaneous augmentation in peak plasma concentration (2 to 1.5-fold higher).