Azilsartan-nicotinamide cocrystal: Preparation, characterization and in vitro / vivo evaluation

Biochanin-A co-crystal formulation improves bioavailability and ameliorates cerulein-induced pancreatitis by attenuating the inflammation

Co-crystallization of a therapeutic ingredient with an appropriate co-former is a powerful technique to augment the physicochemical and pharmacokinetic properties and the effectiveness of Active Pharmaceutical Ingredients (APIs). Biochanin A (BCA), a flavonoid with medicinal potential, is limited by poor solubility and low oral bioavailability. This study aimed to design and develop a novel BCA-nicotinamide cocrystal as BCC to enhance BCA's oral bioavailability and explore its therapeutic potential for ameliorating cerulein-induced acute pancreatitis (CIAP) by elucidating the target identification utilizing tissue/serum metabolite profiles. The cocrystal was designed by the supramolecular synthon approach and characterized by single-crystal X-ray diffraction that confirms a robust three-dimensional hydrogen-bonded network of BCA and Nicotinamide (NCT) in the crystal. FT-IR and DSC were used to analyze the cocrystal's intermolecular interactions and thermal behavior. BCC exhibited enhanced solubility and drug release compared to BCA alone, resulting in enhanced oral bioavailability and pancreatic tissue concentration. Comparing BCC to BCA in the CIAP model, BCC therapy remarkably reduced cerulein-induced pancreatitis, evidenced by significant reductions in inflammation, acinar cell atrophy, and amylase levels in pancreatic tissues. Further, the cocrystal formulation also down-regulated the oxidative stress markers, inflammatory cytokines and macrophage-related proteins. The study has identified distinct metabolomic signatures linked with AP with the help of Orbitrap Exploris mass spectrometry, which could pave the way for creating focused diagnostic tools for a better prognosis. In conclusion, these results offer new insights into exploring mechanistic pathways associated with specific biomarkers and underscore BCC cocrystal as a promising approach to enhance BCA's therapeutic potential.

Novel Pharmaceutical Cocrystal Consisting of Chlorzoxazone and Nicotinamide: A New Promising Carrier for Solubility Augmentation

Chlorzoxazone (CHZ) is a centrally acting muscle relaxant used to treat muscle spasms. It is employed as a first-line medication for treating muscle spasms, offering both musculoskeletal relaxation and mild sedative effects. According to the biopharmaceutics classification system, it belongs to class II drug having poor solubility and high permeability. In order to improve the flow property, water solubility, and dissolution of CHZ, CHZ-nicotinamide (NA) cocrystal was prepared by liquid-assisted grinding cocrystallization (LAG CC) method using methanol as the choice of solvent. CHZ-NA cocrystal was characterized by differential scanning calorimeter (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectrometry, and scanning electron microscopy (SEM). DSC scan showed a sharp endothermic peak shift, which is caused by the formation of a new crystal form with altered physical properties, which was further confirmed by PXRD. Also, a change in the surface morphology of LAG CC compared to CHZ was observed in SEM. The resultant CHZ-NA cocrystal displayed improved powder flow properties compared to the native form of CHZ. LAG CC demonstrated a 3.1- and 2.6-fold increase in saturated solubility and intrinsic dissolution rate, respectively, compared to CHZ alone. Furthermore, the in vitro dissolution study showed that the cumulative dissolution of CHZ in 2 h was about 53%. Whereas, dissolution of LAG CC reached 99% in 2 h, showing obvious dissolution improvement. Thus, CHZ-NA cocrystal could significantly improve the flow properties, solubility and dissolution of CHZ.

Improved photostability, solubility, hygroscopic stability and antimicrobial activity of fleroxacin by synthesis of fleroxacin-D-tartaric acid pharmaceutical salt

To improve the solubility of the fluoroquinolone drug fleroxacin (FL), based on the previous experience of our research group in synthesizing co-crystals/salts of quinolone drugs to improve the physicochemical properties of drugs, Fleroxacin-D-tartaric acid dihydrate salt (FL-D-TT, C17H19F3N3O3·C4H5O6·2(H2O)), was synthesized for the first time using fleroxacin and D/L-tartaric acid (D/L-TT). Structural characterization of FL-D-TT was carried out using single-crystal X-ray diffraction, infrared spectral analysis (FT-IR) and powder X-ray diffraction (PXRD). Molecular electrostatic potential analysis showed that D-tartaric acid interacted more readily with FL than L-tartaric acid. The solubility of FL-D-TT (9.71 mg/mL, 1.82 mg/mL) was significantly higher compared to FL (0.39 mg/mL, 0.71 mg/mL) in water and buffer solution at pH 7.4. This may be attributed to the formation of charge-assisted hydrogen bonds (CAHBs) between FL and D-TT that facilitates the dissociation of FL cations in the dissolution medium, leading to an increase in FL solubility. This also led to some improvement in the in vitro antimicrobial activity of FL-D-TT against E. coli, S. typhi, and S. aureus. In addition, the hygroscopic stability of FL has been improved. Surprisingly, FL-D-TT had better photostability than FL, which could be attributed to the introduction of D-TT to make the photosensitizing moiety of FL more stable, which led to the improvement of the photostability of FL.

New Perspectives for Antihypertensive Sartans as Components of Co-crystals and Co-amorphous Solids with Improved Properties and Multipurpose Activity

Sartans (angiotensin II receptor blockers, ARBs), drugs used in the treatment of hypertension, play a principal role in addressing the global health challenge of hypertension. In the past three years, their potential use has expanded to include the possibility of their application in the treatment of COVID-19 and neurodegenerative diseases (80 clinical studies worldwide). However, their therapeutic efficacy is limited by their poor solubility and bioavailability, prompting the need for innovative approaches to improve their pharmaceutical properties. This review discusses methods of co-crystallization and co-amorphization of sartans with nonpolymeric, low molecular, and stabilizing co-formers, as a promising strategy to synthesize new multipurpose drugs with enhanced pharmaceutical properties. The solid-state forms have demonstrated the potential to address the poor solubility limitations of conventional sartan formulations and offer new opportunities to develop dual-active drugs with broader therapeutic applications. The review includes an in-depth analysis of the co-crystal and co-amorphous forms of sartans, including their properties, possible applications, and the impact of synthetic methods on their pharmacokinetic properties. By shedding light on the solid forms of sartans, this article provides valuable insights into their potential as improved drug formulations. Moreover, this review may serve as a valuable resource for designing similar solid forms of sartans and other drugs, fostering further advances in pharmaceutical research and drug development.

5-fluorouracil-caffeic acid cocrystal delivery agent with long-term and synergistic high-performance antitumor effects

Aim: To explore how to transform cocrystals of the anticancer drug 5-fluorouracil (FL) with caffeic acid (CF; FL-CF-2H₂O) into a nanoformulation, a self-assembly strategy of cocrystal-loaded micelles is proposed. Methods: Nanomicelles were assembled to deliver cocrystal FL-CF-2H₂O with synergistic activity, and their in vitro/vivo properties were evaluated by combining theoretical and experimental methods. Result: More cocrystal was packed into the polymers due to the stronger interaction energy during micellar assembly, producing excellent cytotoxicity and pharmacokinetic behavior, especially synergistic abilities and long-term therapy. Conclusion: This case exemplifies the particular benefits of the self-assembly strategy of cocrystal-loaded micelles in keeping a delicate balance between long-term effects and high efficiency for FL, and offers a feasible technical scheme for cocrystal delivery agents for antitumor drugs.