The invention provides an amorphous metal-organic framework for use in methods of treatment. The amorphous metal-organic framework may hold a component for delivery. The amorphous metal-organic framework is obtained or is obtainable by amorphization of a crystalline amorphous metal-organic framework holding the component. The amorphous metal-organic framework may be a zirconium-containing or a bismuth-containing metal-organic framework, such as a framework having arylcarboxylate ligands, such as benzenedicarboxylate ligands.
