Assessment of the environmental fate and effects of azilsartan, a selective antagonist of angiotensin II type 1

Azilsartan piperazine salt solvate and monohydrate: preparation, crystal structure, enhanced solubility and oral bioavailability

Two azilsartan–piperazine salt solvates and a monohydrate feature crystal structural diversity and improve the azilsartan solubility over that of the free Az form. Az–Pz·EtOH and Az–Pz·H₂O improve the plasma azilsartan concentration C_max and AUC over the free Az form.

Study on Enhanced Dissolution of Azilsartan-Loaded Solid Dispersion, Prepared by Combining Wet Milling and Spray-Drying Technologies

The purpose of this study was to develop a combination method of wet milling and spray-drying technologies to prepare the solid dispersion and improve the dissolution rate of poorly water-soluble drug candidates. Azilsartan (AZL) was selected as the model drug for its poor water solubility. In the study, AZL-loaded solid dispersion was prepared with polyethylene glycol 6000 (PEG6000) and hydroxypropyl cellulose with super low viscosity (HPC-SL) as stabilizers by using combination of wet grinding and spray-drying methods. The high AZL loading solid dispersion was then characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Besides, dissolution test was carried out by the paddle method and stability investigation was also conducted. As a result, the dissolution rate of the solid dispersion tablets was found to be greater than conventional tablets, but in close agreement with market tablets. Furthermore, the formulation was shown to be stable at 40 ± 2°C and 75 ± 5% for at least 6 months, owing to its decreased particle size, morphology, and its crystal form. It was concluded that the combination of wet milling and spray-drying approaches to prepare solid dispersion would be a prospective method to improve the dissolution rate of poorly water-soluble drugs.

Crystal structure of azilsartan methyl ester ethyl acetate hemisolvate

The title compound, C₂₆H₂₂N₄O₅ (systematic name: methyl 2-eth­oxy-1-{4-[2-(5-oxo-4,5-di­hydro-1,2,4-oxa­diazol-3-yl)phenyl]benz­yl}-1H-1,3-benzo­diazole-7-carboxyl­ate ethyl acetate hemisolvate), was obtained via cyclization of methyl (Z)-2-eth­oxy-1-{(2′-(N′-hy­droxy­carbamimido­yl)-[1,1′-biphen­yl]-4-yl)meth­yl}-1H-benzo[d]imidazole-7-carboxyl­ate with diphen­yl carbonate. There are two independent mol­ecules (A and B) with different conformations and an ethyl acetate solvent mol­ecule in the asymmetric unit. In mol­ecule A, the dihedral angle between the benzene ring and its attached oxa­diazole ring is 59.36 (17); the dihedral angle between the benzene rings is 43.89 (15) and that between the benzene ring and its attached imidazole ring system is 80.06 (11)°. The corres­ponding dihedral angles in mol­ecule B are 58.45 (18), 50.73 (16) and 85.37 (10)°, respectively. The C—O—C—C_m (m = meth­yl) torsion angles for the eth­oxy side chains attached to the imidazole rings in mol­ecules A and B are 93.9 (3) and −174.6 (3)°, respectively. In the crystal, the components are linked by N—H⋯N and C—H⋯O hydrogen bonds, generating a three-dimensional network. Aromatic π–π stacking inter­actions [shortest centroid–centroid separation = 3.536 (3)Å] are also observed.