Physicochemical and crystal structure analysis of pranlukast pseudo-polymorphs II: Solvate and cocrystal

Transferability of cocrystallization propensities between aromatic and heteroaromatic amides

“…Also many other physicochemical properties can be modulated by cocrystallization including stability [21][22][23][24], hygroscopicity [25] and prolonged shelf life [26]. Among many drugs, aromatic amides acting either as APIs or as excipients attract nowadays substantial attention [27][28][29][30][31][32][33][34][35]. These compounds are known for their important roles in medical applications.…”

“…Although many pharmaceutical cocrystals containing amides have been studied [27][28][29][30][31][32][33][34][35], the data deposited in the Cambridge Structural Database (CSD) [41] are rather variable in the sense that many coformers were used for synthesis of diverse cocrystals. For example cocrystals of fumaric acid with benzamide, isonicotinamide or nicotinamide are known under refcodes YOPBUB, LUNNOX and EDAPOQ, respectively, but there is no information about solids of these coformers with temozolomide.…”

Investigation of a solution‐mediated phase transformation of pranlukast DMF solvate to hemihydrate

“…Pranlukast (N‐[4‐oxo‐2‐(1H‐tetrazol‐5‐yl)‐4H‐chromen‐7‐yl]‐4‐(4‐phenylbutoxy) benzamide, PRS, Figure ) is a potent selective cysteniyl leukotriene receptor antagonist to treat bronchial asthma and allergic rhinitis . PRS has several crystalline forms , including the anhydrous form I, the anhydrous form II, the anhydrous form III, the hemihydrate form (HH), the N,N‐Dimethylformamide solvate (PRS/DMF), and the ethanol solvate (PRS/ethanol), etc. The marketed form of PRS is the hemihydrate form.…”

“…PRS showed limited solubility in most of the organic solvents, with the exception of DMF where a 25 mg/mL of solubility was achieved at room temperature, which made DMF a necessary solvent for the crystallization of PRS in pharmaceutical industry. However, PRS tends to form 1:1 stoichiometric solvate with DMF , causing a relatively large amount of DMF residue in the final crystalline product. Direct crystallization of the desired hemihydrate from DMF solution while avoiding the formation of PRS/DMF will simplify the production process and save a lot of resource.…”

“…Therefore, there is a practical need to investigate the phase transformation from PRS/DMF to HH. Furuta et al reported the crystal structure information of the two polymorphs of PRS. HH crystallized in a triclinic crystal system and space group P‐1, whereas PRS/DMF was in the monoclinic crystal system and space group P2 1 /a.…”