Patentability of polymorphs
Research in the field of polymorphism is strategical in the pharma industry as polymorphs represent different crystalline forms of drug products that may have different and advantageous physicochemical properties with respect to the reference API (active pharmaceutical ingredient) and may be potentially patentable.
The increasing awareness of the importance of such research field is witnessed by the trend shown by the number of patent applications published per year in the last five years period (2013 to 2017), as reported in Figure 1 (1).
APIs frequently delivered to the patient in the solid-state as part of an approved dosage form, can exist in various solid forms (salts, hydrates, solvates, co-crystals, amorphous solids, polymorphs, etc.), which often show different mechanical, thermal, physical and chemical properties that can considerably affect a drug’s potential. Among such different solid forms, polymorphs are of particular interest, since different polymorphs, i.e. different crystalline forms, of the same active pharmaceutical ingredient (API) usually show distinct physicochemical properties, such as melting point, solub ...