Olanzapinium Salts, Isostructural Solvates, and Their Physicochemical Properties

Solubility and dissolution play a crucial role in the activity and efficacy of an oral drug. Olanzapine is an antipsychotic drug of the Biopharmaceutics Classification System (BCS) class II category. Several solvates, cocrystals, salts, and amorphous forms of olanzapine have been prepared to study materials properties and its X-ray crystal structures were classified. We report herein a few salts, solvates, and solvate polymorphs of olanzapine to improve the physicochemical properties and study novel structural motifs. Olanzapinium dimaleate monofumaric acid is the first case of a ternary cocrystal of an active pharmaceutical ingredients (API) in the CSD database with maleate ion and fumaric acid coformers. The olanzapine disalts, olanzapinium dipicrate, dimaleate, and dimaleate monofumaric acid, contain a novel structural motif, different from the dimer motif characteristic of the four structural categories reported in the literature.