Improving the filterability and solid density of ranitidine hydrochloride form 1

Characterization of tautomeric forms of ranitidine hydrochloride: thermal analysis, solid-state NMR, X-ray

“…There are methods [8][9][10] , which produce Form 1 with minimum bulk solid density of 0.23 g/ml. Some extensive studies by the authors have led to the production of Form 1 with bulk density in the range of 0.26-0.32 g/ml with well-formed rectangular crystals and will be reported elsewhere [15].…”

Relationship between crystal structure and mechanical properties of ranitidine hydrochloride polymorphs

“…Therefore, selective crystallization from various solvents is observed. 18,29 Crystallization from anhydrous and less polar solvents led to the formation of the form I having a strong intra-molecular hydrogen bonding, producing dense packing of molecules. 18 Whereas presence of water or the highly polar solvents led to the generation of form II disrupting intra-molecular hydrogen bonding, ending up as an open structure in form II.…”

An approach to solvent screening for crystallization of polymorphic pharmaceuticals and fine chemicals

“…During reactive crystallization of ranitidine hydrochloride, RAN‐B molecules exist in the solution, which establish hydrogen bonding with RAN‐HCl and solvent molecules. Mirmehrabi et al17 showed that the hydrogen bonding between RAN‐B and RAN‐HCl molecules during cluster formation delays the nucleation of RAN‐HCl crystals due to the difference in their solubilities.…”