Synthesis and Characterization of a New Norfloxacin/Resorcinol Cocrystal with Enhanced Solubility and Dissolution Profile

Cocrystals Enhance Biopharmaceutical and Antimicrobial Properties of Norfloxacin

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.

Norfloxacin Cocrystals: Mechanochemical Synthesis and Scale-up Viability Through Solubility Studies

Cocrystals are recognized as one of the most efficient approaches to improve aqueous solubility of Biopharmaceutical Classification System, BCS, classes II and IV drugs. Cocrystal discovery and the establishment of experimental conditions suitable for scale-up purposes are some of the main challenges in cocrystal investigation. In this work, the investigation of mechanochemical synthesis of norfloxacin cocrystals with picolinic and isonicotinic acids is performed, leading to the discovery of two new cocrystals of this important BCS class IV antibiotic, which were characterized through thermal, spectral and diffractometric analysis. Norfloxacin apparent aqueous solubility using the cocrystals is also presented, with higher values being obtained for all the investigated systems when compared to the pure drug. Norfloxacin has 3 polymorphs and several solvents/hydrates, which represents a challenge for obtaining pure cocrystal forms from solvent crystallization. This challenge was successfully overcome in this work, as experimental conditions to obtain the pure cocrystals (the new ones and also norfloxacin-nicotinic acid and norfloxacin-saccharin) were established using Crystal16 equipment. This is a crucial step to envisage future scale-up procedures and therefore a valuable information for the pharmaceutical industry.

A Review of Coformer Utilization in Multicomponent Crystal Formation

Most recently discovered active pharmaceutical molecules and market-approved medicines are poorly soluble in water, resulting in limited drug bioavailability and therapeutic effectiveness. The application of coformers in a multicomponent crystal method is one possible strategy to modulate a drug's solubility. A multicomponent crystal is a solid phase formed when several molecules of different substances crystallize in a crystal lattice with a certain stoichiometric ratio. The goal of this review paper is to comprehensively describe the application of coformers in the formation of multicomponent crystals as solutions for pharmaceutically active ingredients with limited solubility. Owing to their benefits including improved physicochemical profile of pharmaceutically active ingredients, multicomponent crystal methods are predicted to become increasingly prevalent in the development of active drug ingredients in the future.

Virtual Cocrystal Screening of Adefovir Dipivoxyl: Identification of New Solid Forms with Improved Dissolution and Permeation Profiles

The application of a computational screening methodology based on the calculation of intermolecular interaction energies has guided the discovery of new multicomponent solid forms of the oral antiviral Adefovir Dipivoxyl. Three new cocrystals with resorcinol, orcinol and hydroquinone have been synthesized and thoroughly characterized. They show improved dissolution profiles with respect to the single solid form, particularly the cocrystals of orcinol and resorcinol, which have 3.2- and 2-fold faster dissolution rates at stomach conditions (pH 1.5). Moreover, dynamic dissolution experiments that simultaneously mimic both the pH variation along the gastrointestinal tract and the partition into biological membranes show that, in addition to the faster initial dissolution, Adefovir Dipivoxyl also penetrates faster into the organic membranes in the form of resorcinol and orcinol cocrystals.

Experimental and Hirshfeld Surface Investigations for Unexpected Aminophenazone Cocrystal Formation under Thiourea Reaction Conditions via Possible Enamine Assisted Rearrangement

Considering the astounding biomedicine properties of pharmaceutically active drug, 4-aminophenazone, also known as 4-aminoantipyrine, the work reported in this manuscript details the formation of novel cocrystals of rearranged 4-aminophenazone and 4-nitro-N-(4-nitrobenzoyl) benzamide in 1:1 stoichiometry under employed conditions for thiourea synthesis by exploiting the use of its active amino component. However, detailed analysis via various characterization techniques such as FT-IR, nuclear magnetic resonance spectroscopy and single crystal XRD, for this unforeseen, but useful cocrystalline synthetic adduct (4 and 5) prompted us to delve into its mechanistic pathway under provided reaction conditions. The coformer 4-nitro-N-(4-nitrobenzoyl) benzamide originates via nucleophilic addition reaction following tetrahedral mechanism between para-nitro substituted benzoyl amide and its acid halide (1). While the enamine nucleophilic addition reaction by 4-aminophenazone on 4-nitrosubstituted aroyl isothiocyanates under reflux temperature suggests the emergence of rearranged counterpart of cocrystal named N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carbonothioyl)-4-nitrobenzamide. Crystallographic studies reveal triclinic system P-1 space group for cocrystal (4 and 5) and depicts two different crystallographically independent molecules with prominent C–H···O and N–H···O hydrogen bonding effective for structure stabilization. Hirshfeld surface analysis also displays hydrogen bonding and van der Waals interactions as dominant interactions in crystal packing. Further insight into the cocrystal synthetic methodologies supported the occurrence of solution-based evaporation/cocrystallization methodology in our case during purification step, promoting the synthesis of this first-ever reported novel cocrystal of 4-aminophenazone with promising future application in medicinal industry.

Expanding the solid-state landscape of dexamethasone: a specific sandwich structure in facilitating the formation of kinetically stable cocrystals from mechanochemistry

We herein report the successful synthesis of the first two dexamethasone cocrystals from mechanochemistry.

Solubility and permeability enhancement of BCS class IV drug ribociclib through cocrystallization

Cocrystallization improves the solubility and permeability of BCS class IV anticancer drug ribociclib as a cocrystal with resorcinol and as a salt hydrate with vanillic acid.