Information for Effective Co-crystal Patents

Effective patenting of co-crystals focuses primarily on two considerations (1) the characterization and proof of actual co-crystal and (2) the properties of the co-crystal. The first is perhaps more important than the second, although as discussed above, the co-crystal must possess practical utility and usefulness. That practical utility is often directly related to the properties of the co-crystal and, sometimes, even the existence of the co-crystal, as a solid-state form of the API, solves the problem of handling, processing, and/or formulating the API. 

Co-crystal patents usually contain experimental examples that describe the preparation of the co-crystal and the characterization of the co-crystal. Characterization of the co-crystal describes the co-crystal itself and its various properties which include its sohd state characteristics and stoichiometry. Typically, the sohd state characteristics of a crystalline solid are shown by one or more of the foUowing analytical techniques X-ray powder diffraction pCRPD), single crystal X-ray diffraction (SCXD), Raman spectroscopy, infrared (IR) spectroscopy, sohd state nuclear magnetic resonance spectroscopy (SSNMR), and differential scanning calorimetry (DSC). The stoichiometry of a co-crystal may be estabhshed through solution techniques such as comparison of peak integrations in a solution NMR spectrum, data 

Co-crystal patents, then, describe and disclose a co-crystal as a new composition of matter. Similar to the traditional composition of matter patents, they establish the existence and identity of the co-crystal. Because of a cocrystal s unique bonding interaction between the API and co-former(s), a cocrystal patent takes as prior art its constituent parts and establishes those by comparison. The properties and advantages of the co-crystal and the arguments for its patentability are also made in comparison with the API and its properties. It is from these comparisons that effective co-crystal patents are constructed. 

This chapter has merely surveyed some ways in which co-crystals may translate into new patents and commercial value and has discussed some considerations for accomplishing this. It is clear that the success of co-crystals in commercialization and as new patents is tied to their unique chemical composition, crystalline structure, and properties. Engineering pharmaceutical properties using co-crystals can create new commercial value for an API and extend its patent life. This value comes from the composition of the co-crystal as well as from its crystalline form. Patenting co-crystals captures that value in the form of intellectual property. Yet, co-crystal patents have their own unique aspects to be addressed as can be seen from the discussion of the definition of cocrystal , the patentability of co-crystals, and the information needed for 

Lindeman thanks Paul Burgess, M.S., J.D. of Segrub Pharmaceuticals for bringing US Patent No. 3,028,420 to his attention. 

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