A growing number of co-crystals in the literature are proof of how significant the co-crystallization concept has become. Co-crystallization enhances physicochemical properties through the formation of intermolecular interactions between a drug and a co-former. A co-crystal is a single crystalline material consisting of at least two molecular components solid at room temperature and present in a definite stoichiometric ratio. Pharmaceutical co-crystals consist of the active pharmaceutical ingredient and the co-former selected from generally regarded as safe (GRAS) list of the United State Food and Drug Administration. Co-crystal formation requires an understanding of a drug target, a proper choice of a co-former and is only achieved experimentally after several trials. Other beneficial co-crystallization outcomes include binary eutectics, solid dispersions, amorphous forms, etc. Several key issues including design strategies, co-former selection, and co-crystallization methods; tradition and newly synthetic methods that are more efficient and suitable for large scale have been briefly described. The co-crystal preference is demonstrated with a particular emphasis on multidrug co-crystals and their contribution to the drug combination strategies used for the treatment and management of drug resistance and adverse side effects in serious medical conditions that require the administration of high doses such as HIV/AIDS, tuberculosis, and others. K E Y W O R D S co-crystal development, co-crystallization, design, pharmaceutical co-crystals, preferences, synergistic co-crystals 1 INTRODUCTION Less than 1% of active pharmaceutical ingredients (APIs) reach the market because of poor biopharmaceutical properties among which solubility plays a key role. [1] Poor physicochemical properties of APIs such as chemical stability, dissolution, hygroscopicity, and solubility impact This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

No abstract

The present work reports two novel pharmaceutical co-crystals; 2:1 isoniazid-glutaric acid (INHGA) and 2:1 pyrazinamide-glutaric acid (PGA). Isoniazid and pyrazinamide are key first-line drugs used for the treatment of tuberculosis. The co-crystals were produced via solid-state and solvent assisted grinding methods. Thermal characteristics of the samples were obtained using the differential scanning calorimetry, hot stage microscopy, and thermogravimetric analyses. The morphology of the powder samples by scanning electron microscopy, structural analysis by Fourier transform infrared spectroscopy and powder X-rays diffraction ensured co-crystal formation. Thermal analyses confirmed the co-crystals with new melting transitions ranging between their respective starting materials. Unique morphologies of the co-crystal particles were clear in SEM micrographs. The formation of intermolecular interactions with the co-crystal former was confirmed by the FT-IR spectral band shifting and was supported by distinct PXRD patterns of co-crystals thereby authenticating the successful co-crystal formation. In vitro solubility evaluation of the synthesized co-crystals by HPLC suggested a remarkable increase in solubility of both INH and PZA in their respective co-crystals.

This work reports for the first time the possibility of green synthesis and the antibacterial effect of silver nanoparticles (AgNPs) on commercialized polycarbonate membrane. The AgNPs were loaded on the polycarbonate membrane serving as the substrate via ultra-sonication and centrifugation. The extracts from the red flowers of Callistemon viminalis were used as the chelating agent. The synthesised thin film silver nanoparticles were characterized by various techniques such as Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier transform-infrared (FT-IR), X-Ray diffraction and UV-Vis spectroscopy. Consequently, the antibacterial affect was studied. The synthesised thin film silver nanoparticles had a surface plasmon resonance of 310nmand show a very effective inhibition growth of both Gram-positive and Gram-negative.

No abstract