Search Results (505)

The present study investigates the co-crystallization process of rivaroxaban (RIV), a poorly water-soluble potent oral anticoagulant, with niacinamide (NIA), a highly soluble and pharmaceutically acceptable co-crystal former, in two different molar ratios (1:1 and 1:2). The aim was to enhance the physicochemical and biopharmaceutical properties of rivaroxaban such as dissolution rate and aqueous solubility, by forming stable co-crystals through a solvent evaporation technique. The resulting co-crystals (RIV-NIA, 1:1 co-crystallization compound, F1 and RIV-NIA, 1:2 co-crystallization compound, F3) were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) and thermal analysis, which confirmed the formation of a new rivaroxaban–niacinamide co-crystalline phase. In vitro dissolution studies confirmed a significant enhancement in the dissolution rate of the two obtained co-crystals. These findings suggest that stoichiometric variation plays an important role in co-crystal performance and in improving solubility compared with the pure drug. Also, the obtained results suggest that niacinamide is an effective coformer for improving the dissolution and physicochemical properties of rivaroxaban. Full article

Two novel cocrystals of zwitterionic trimethylglycine (TMG) with 2,6-dichlorophenol [TMG•2,6-dichlorophenol] (1:1) and 2,6-dibromophenol [TMG•2,6-dibromophenol] (1:2) are synthesized and structurally characterized using single crystal X-ray diffraction. To estimate the energy of various intermolecular interactions, periodic DFT calculations were performed followed by Bader analysis of the crystalline electron density. TMG molecules form dimers in [TMG•2,6-dichlorophenol] (1:1). Its supramolecular structure is governed by the primary charge-assisted H-bonds (~60 kJ/mol) and supported by C–H∙∙∙O contacts (~12 kJ/mol). Cl/Br substitution introduces a more potent halogen-bonding donor. The Br∙∙∙O⁻ interaction (~10 kJ/mol) is strong enough to reorganize the packing into a catemeric motif. As a result, TMG molecules form infinite chains in [TMG•2,6-dibromophenol] (1:2). This illustrates that “fine tuning” is not merely about changing distances, but about shifting the entire energy hierarchy of the crystal. Two-dimensional fingerprint diagrams (2D diagrams) obtained from the Hirshfeld surface and Bader’s analysis of the crystalline electron density give significantly different values of the contributions of the H∙∙∙H contacts, 28% vs. 5% respectively. The main reason for this discrepancy is the large number of relatively short intermolecular H∙∙∙H contacts without a critical bond point in trimethylglycine cocrystals. Full article

Calcium oxalate (CaOx) crystals in plants can form naturally within their idioblasts but may also be induced by other factors, such as environmental pollution. Here, we report qualitative and semiquantitative results obtained using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) from two experiments in which tomato seedlings were moderately irrigated with Sulfamethoxazole (SMX) and Amoxicillin (AMX) solutions (0.25 mM). Abundant prismatic CaOx co-crystals appeared on the leaf surface induced by these two antibiotics compared to the distilled water (DW) control. Applying a non-thermal plasma (NTP) treatment for 20 min (T20) to the SMX initial solution led to a dramatic suppression of these crystals, with a shift toward spherical structures. Furthermore, the investigation into the composition of both crystal types, indicated different percentual levels of O, C, Ca, K, Mg, S, and Mn as main constituent minerals involved in crystal formation. However, crystal morphology was affected by each applied experimental condition, while detecting their constituent elements depended on their mineral homogeneity at the micro- or macro-field scales. Although both antibiotics induced crystal formation and T20 phenotypically reduced the abundance of the acicular–prismatic crystals by removing the effects of SMX, their mode of action has not yet been clarified. Full article

Phenothiazine is a heteroaromatic molecule capable of various noncovalent interactions, including halogen bonding and π-stacked association. Despite its broad use in functional materials and pharmaceutical ingredients, a systematic comparison of these interaction modes has been lacking. Here, we report a combined experimental and computational study of intermolecular interactions of phenothiazine with a prototypical halogen-bond (HaB) donor (tetrabromomethane), planar π-electron acceptors (tetracyanopyrazine and tetrafluoro-p-benzoquinone), and multifunctional species capable of both interaction types (iodo- and bromo-3,5-dinitrobenzenes). X-ray structural analysis revealed that CBr₄ forms exclusively C–Br···π halogen bonds with the aromatic rings of phenothiazine, whereas all π-acceptors yield alternating donor–acceptor stacks characterized by multiple short contacts indicative of multicenter interactions. Notably, co-crystals of iodo- and bromodinitrobenzenes with phenothiazine display only π-stacked architectures. Density-functional calculations showed that isolated HaB complexes involving N, S, or π sites of phenothiazine possess comparable binding energies (≈−3 kcal mol⁻¹), whereas π-stacked complexes are substantially stronger (≈−9–12 kcal mol⁻¹). QTAIM, NCI, NBO, and energy-decomposition analyses indicated that while amounts of charge transfer in halogen-bonded and π-stacked complexes are comparable, the enhanced stability of the latter originates primarily from a large dispersion contribution. These results rationalize the solid-state preference for π-stacking over halogen bonding in systems where both motifs are accessible and clarify the hierarchy and physical origin of noncovalent interactions involving phenothiazine, providing guidance for the design of supramolecular assemblies and functional materials based on this versatile electron donor. Full article

Background/Objectives: Cocrystallisation is a well-established path for altering the physicochemical properties and bioavailability of active pharmaceutical ingredients (APIs). A common side effect of anti-tubercular medicines is the depletion of group B vitamin reserves in TB patients. Co-administration of supplements such as pyridoxine (vitamin B₆) during TB therapy may be used to ameliorate the harmful side effects of vitamin B₆ deficiency. Methods: Mechanochemical grinding and solvent evaporation experiments using pyridoxine (PN) with 4-aminosalicylic acid (PAS) and separately with pyrazinecarboxylic acid (PCBA) were conducted. The bulk powder and crystal analysis was performed using FTIR, PXRD, DSC, TGA and SCXRD. Results: The isolation and characterization of two multicomponent salts containing pyridoxine, i.e., PN-PAS·H₂O and PN-PCBA, were completed. Mechanochemistry is an efficient method for the preparation of cocrystals. Conclusions: The drug–vitamin combinations may be useful for the development of new treatment regimens with potentially improved therapeutic outcomes and reduced adverse effects. Full article

Betaine, a simple natural zwitterion, is currently attracting widespread attention. Although historically labeled as an osmoregulator in agriculture and a methyl donor in animal nutrition, the molecule is now being repositioned at the forefront of green chemistry and materials science due to its unique physicochemical structure. This review critically explores the expanding horizon of betaine applications, bridging the gap between its established biological functions and its emerging roles in recently reported technologies, such as deep eutectic solvents (DESs), cocrystal engineering, and sustainable polymer synthesis. Beyond summarizing its versatile functionality across biomedicine, food science, and industrial formulations, we provide a comprehensive bibliometric analysis to map the evolution of research trends, identifying a clear focus toward industrial ecology and advanced materials. By synthesizing current advancements and discussing potential future directions, this work highlights betaine not merely as a supplement, but as a versatile molecular component with potential applications in sustainable materials and chemical engineering processes. Full article

This study contains a combination of a review and a related individual case study, which discusses the possibility of predicting the success of enantiomers’ optical separation using fractional crystallization of diastereomeric salts. The key idea is to use relatively simple and rapid experimental methods, such as differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD), to construct ternary melting diagrams. These diagrams can be used for visualization and predicting compositional conditions favorable for successful separation. The main limitations are also mentioned, such as the ideal eutectic behavior of components and the need to identify all crystalline phases in the system. For demonstration, three novel studies, attempts in ternary resolution systems of racemic o- and p-chloromandelic acids with chiral 1-cyclohexylethylamine or pregabalin, resulting in either declined or promising aspects for a successful resolution, were completed, and the corresponding individual ternary phase diagrams have been compiled and presented, as well. In addition, indexing and modeling of one of the diastereomeric salts’ unit cells have been successfully carried out by means of powder X-ray diffraction, using the DASH software package. Full article

Papain-like protease (PLpro), a crucial functional domain of the SARS-CoV-2 non-structural protein 3 (nsp3), plays a dual role in both hydrolyzing viral polyprotein precursors and modulating host immune responses. These critical functions position PLpro as a key target in the ongoing development of antiviral therapies for SARS-CoV-2. This review analyzes more than 100 PLpro-ligand co-crystal structures and summarizes the major binding modes between these ligands and PLpro. Most of these ligands bind to sites analogous to those targeted by the classical non-covalent inhibitor GRL0617, primarily involving the P3 and P4 subsites and the BL2 loop. Based on these structural insights, optimized inhibitors have expanded targeting beyond the canonical binding site to auxiliary regions such as the BL2 groove and the Val70 site, and in some cases toward the catalytic Cys111 buried within a narrow pocket. Certain ligands identified through various screening approaches bind to non-canonical or allosteric regions, such as the S1 and S2 sites or the zinc-finger domain, engaging PLpro through distinct interaction modes and thereby offering additional opportunities for PLpro inhibitor design. The review also discusses potential strategies for future PLpro inhibitor development informed by recent structural advances. Taken together, these structural and functional insights support ongoing efforts in the structure-guided design and optimization of PLpro inhibitors. Full article

Pharmaceutical cocrystals are a well-established class of solid-state forms that can modulate the solubility, dissolution, stability, and bioavailability of active pharmaceutical ingredients without altering their molecular identity. Although traditional oral formulations have demonstrated translational potential, recent research has emphasized the importance of integrating cocrystals into emerging drug-delivery technologies. This review systematically analyzes recent advances in conventional and innovative cocrystal-based platforms, critically evaluating their therapeutic relevance. A comprehensive literature search was conducted, focusing on publications from the last decade, with emphasis on studies from 2020 to 2025, including peer-reviewed articles, patents, and regulatory documents. Evidence was organized into traditional oral, inhalable, intranasal, and transdermal formulations, followed by emerging platforms such as 3D printing, nano-cocrystals, and microneedles. Case studies and preclinical/clinical data were critically assessed to identify strengths, limitations, and future directions. Advancements in formulation science and novel delivery technologies are allowing pharmaceutical cocrystals to transition from laboratory innovations to clinical applications. Despite challenges in scalability, stability, and regulatory clarity, the application of cocrystals into emerging platforms highlights their potential as transformative tools in next-generation therapeutics. Full article

Rosuvastatin calcium is a promising lipid-lowering agent and the drug of choice in hyperlipidemia. Conventional solid oral delivery of rosuvastatin is limited by its poor solubility and ultimately poor bioavailability. An attempt was made to fabricate the cocrystals of RSC for enhancing solubility and bioavailability. Cocrystals were prepared by a microwave synthesiser-assisted solvent evaporation technique with multiple cocrystal formers. Rosuvastatin-Ascorbic acid (RSC-AA) cocrystals showed the highest solubility (~5-fold increased) amongst all twenty drug-coformer combination (DCC). RSC-AA cocrystals (1:1 ratio) were further characterized by various analytical techniques like FTIR, DSC and XRD to confirm the formation of cocrystals. RSC-AA cocrystals also showed improved flow properties and compressibility in comparison with pure drug, and it was demonstrated using the SeDeM diagram. RSC-AA cocrystals were further formulated into an immediate-release tablet by implementing experimental optimization. Comparative dissolution study of the cocrystal and pure drug tablet revealed improved dissolution after cocrystallization. RSC-AA cocrystal tablet showed the % drug release of 95.61 ± 3.94 while RSC pure drug showed the drug release of 67.83 ± 3.29. In vivo pharmacokinetic analysis showed significant improvement in systemic availability and cumulative absorption of the drug. The peak plasma concentration (Cmax) for RSC pure drug was 13.924 ± 0.477 μg/mL, while RSC-AA cocrystals showed a peak plasma concentration of 22.464 ± 0.484 μg/mL. Area Under Curve (AUC) of RSC-AA cocrystal was also significantly greater compared to the pure drug. In the stability study analysis, the shelf life was calculated from a graphical method and was found to be around 34.58 months for RSC-AA cocrystal tablets and 19.87 months for RSC pure drug tablets, which indicates improved stability with cocrystallization. Overall, the cocrystallization resulted in significant improvement in dissolution and solubility of RSC. Full article

The replacement of ionizable functional groups that are predominantly charged at physiological pH with neutral bioisosteres is a common strategy in medicinal chemistry; however, its impact on binding affinity is often context-dependent. Here, we investigated a series of amide derivatives of a glycomimetic E-selectin ligand, in which the carboxylate group of the lead compound is substituted with a range of amide and isosteric analogs. Despite the expected loss of the salt-bridge interaction with Arg97, several amides retained or even improved the binding affinity. Co-crystal structures revealed conserved binding poses across the series, with consistent interactions involving the carbonyl oxygen of the amide and the key residues Tyr48 and Arg97. High-level quantum chemical calculations ruled out a direct correlation between carbonyl partial charges and affinity. Instead, a moderate correlation was observed between ligand binding and the out-of-plane pyramidality of the amide nitrogen, suggesting a favorable steric adaptation within the binding site. Molecular dynamics (MD) simulations revealed that high-affinity ligands exhibit enhanced solution-phase pre-organization toward the bioactive conformation, likely reducing the entropic penalty upon binding. Further analysis of protein–ligand complexes using Molecular mechanics/Generalized born surface area (MM-GB/SA) decomposition suggested minor lipophilic contributions from amide substituents. Taken together, this work underscores the importance of geometric and conformational descriptors, beyond classical electrostatics, in driving affinity in glycomimetic ligand design and provides new insights into the nuanced role of amides as carboxylate isosteres in protein–ligand recognition. Full article

This work aimed to synthesize new derivatives of 2-hydrazinylpyridine-3-carbonitrile and to investigate their biological activity as safeners for the 2,4-D herbicide. The new 2-hydrazinylnicotinonitriles were obtained in high yields (up to quantitative) under mild conditions (25 °C, dioxane) by treating 4,6-diaryl-2-bromo-3-cyanopyridines with hydrazine hydrate. The latter were synthesized by brominating 2-(3-oxo-1,3-diarylpropyl)malononitriles, the Michael adducts, which are readily available from 1,3-diarylpropenones (chalcones) and malononitrile. An unusual side product of the bromination/carbocyclization was isolated and characterized; it consisted of co-crystals of 3-benzoyl-4-hydroxy-4-phenyl-2,6-di-(p-tolyl)cyclohexane-1,1-dicarbonitrile and 3-benzoyl-5-bromo-4-hydroxy-4-phenyl-2,6-di-(p-tolyl)cyclohexane-1,1-dicarbonitrile at a ~4:6 ratio. The new 2-hydrazinylnicotinonitriles react with halogen-containing aromatic aldehydes to form the corresponding hydrazones. The biological activity of the new nicotinonitriles was examined for their function as 2,4-D antidotes. It was found that, under laboratory conditions, eight of the synthesized compounds exhibited a notable antidote effect against 2,4-D on sunflower seedlings. Full article

Flavonoids are naturally occurring compounds with reported anticancer, antimicrobial, anti-inflammatory, cardio-protective and antioxidant effects. They are increasingly incorporated in functional foods designed to promote health, enhance well-being, and support physical performance. However, their practical use is limited because of their low water solubility and poor absorption within the body. An effective strategy for developing new flavonoid-based formulations involves their transformation into molecular complexes (cocrystals) through cocrystallization, a method that has emerged a powerful tool to modulate the physicochemical and biological properties of polyphenols and other relevant drugs. Cocrystals are stabilized through non-covalent interactions, which can introduce new physicochemical properties to the original molecules (coformers) while retaining the chemical properties of the coformers, as no bonds are broken or formed. Flavonoid-based cocrystals can be obtained through a variety of methods using different coformers, and we aim here to review cocrystals containing flavonoids and coformers, with a focus on their methods of synthesis, physicochemical and biological characteristics, as well as their potential applications in both the food and pharmaceutical sectors. Full article

This study investigated the impacts of dietary thymol–carvacrol cocrystal (CEO) supplementation on broiler production performance, antioxidant status, intestinal health, and cecal microbiota. Eight hundred one-day-old chicks were randomly divided into four groups, receiving basal diets supplemented with 0, 40, 60, or 80 mg/kg CEO. The results showed that CEO addition increased average daily gain, superoxide dismutase activity in the serum, liver, and jejunum, jejunal villus height/crypt depth ratio, cecal butyric acid concentration, and Lactobacillus abundance, while reducing serum alanine transaminase activity and malondialdehyde content in the serum, liver, and jejunum. Furthermore, 60 mg/kg CEO enhanced the final body weight, dressing percentage, serum total protein and glucose levels, and jejunal trypsin and amylase activities, while lowering the feed-to-gain ratio and serum cholesterol, urea nitrogen, and aspartate transaminase concentrations; it also increased the activities of superoxide dismutase, catalase, and glutathione and mRNA expressions of related genes in the liver and jejunum. It also increased cecal concentrations of acetic acid and isovalerate acid, while decreasing serum diamine oxidase and D-lactate concentrations, as well as malondialdehyde concentrations in the serum, liver, and jejunum. Therefore, dietary CEO supplementation improved the production performance, antioxidant status, and liver and gut health and function in broilers, with 60 mg/kg CEO demonstrating the most pronounced effects. Full article

Background/Objectives: Pharmaceutical cocrystallization offers a promising strategy to enhance drug properties while preserving molecular integrity. Ezetimibe, a BCS Class II hypolipidemic agent, faces therapeutic limitations due to poor aqueous solubility. This study aimed to systematically evaluate cocrystallization of ezetimibe with organic acid (benzoic, tartaric, or succinic acid) at varying stoichiometric ratios (1:0.5–1:2) to optimize physicochemical properties and oral bioavailability. Methods: Cocrystals were prepared via solvent evaporation (SEV) and solvent/anti-solvent (SAS) methods. Structural characterization included Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder/single-crystal X-ray diffraction (PXRD/SCXRD). Physicochemical performance was assessed through saturation solubility, in vitro dissolution, and in vivo pharmacokinetics in male Sprague Dawley rats (n = 4/group). Results: Benzoic acid cocrystals (1:2 ratio, SEV) showed O−H⋯N hydrogen bonding (FTIR band shifts: 2928 → 3264 cm⁻¹) and novel crystalline phases (12.4°, 16.7°, and 24.9°). SCXRD confirmed monoclinic P2₁/n symmetry (a = 5.42 Å, b = 5.05 Å) for benzoic acid cocrystals. Ezetimibe/benzoic acid cocrystals (1:2) achieved 64-fold solubility enhancement and 2× faster dissolution vs. pure ezetimibe. Pharmacokinetics revealed 3× higher Cmax (18.38 ng/mL) and 4× greater AUC (40.36 h·ng/mL) for optimized cocrystals. Tartaric and succinic acid cocrystals showed moderate improvements, with melting points intermediate between parent compounds. Conclusions: Both stoichiometry and preparation method strongly determined cocrystal performance. Benzoic acid at a 1:2 ratio via SEV demonstrated superior solubility, dissolution, and bioavailability, addressing ezetimibe’s formulation challenges. These findings underscore the potential of rational cocrystal design to overcome solubility barriers in oral dosage development, particularly for hydrophobic therapeutics. Full article