Mechanochemical synthesis of drug–drug and drug–nutraceutical multicomponent solids of olanzapine

Drug–drug and drug–nutraceutical multicomponent solids of an antipsychotic drug olanzapine (OLN) are prepared using mechanochemistry. Drug molecules, viz. , nateglinide (NAT) and pyrazinoic acid (PZO) as well as nutraceuticals, namely, 2,4,6-trihydroxybenzoic acid (246THBA), gallic acid (GA) and sinapic acid (SPA) are used as coformers in this study. After neat grinding (NG), incomplete conversion (partially amorphous) was observed, whereas liquid-assisted grinding (LAG) resulted in the formation of coamorphous OLN–NAT and crystalline salts/salt hydrates of OLN with rest of the coformers, which were characterized using a combination of techniques, including single crystal X-ray diffraction. The OLN–NAT coamorphous salt has a potential scope for development as a combination drug in order to suppress the increase in the blood sugar level, a common side-effect observed during the monotherapy of psychiatric patients using OLN. The equilibrium solubility study shows a substantial enhancement in the solubility of olanzapinium pyrazinoate compared to that of the pure base.