The Commercial Life of a Drug Molecule
A new drug’s commercial life is bounded by its patent estate. The composition of matter patent, which covers the chemical structure of the active ingredient, is typically the most valuable piece of IP and is usually filed at or near the time of initial synthesis. By the time a drug reaches the market, after a development programme that commonly takes ten to fifteen years, much of the composition of matter patent life has already been consumed.
This is where solid form IP becomes commercially significant. A patent covering a novel crystal polymorph, a pharmaceutically beneficial salt form, or a co-crystal with advantages over existing forms can be filed and prosecuted independently of the composition of matter patent, and can provide exclusivity that extends well beyond it.
What Can Be Patented in Solid Form Work
Novel Polymorphs
A new crystalline form of a known API may be patentable if it is novel, non-obvious, and has utility. Patentability is typically supported by demonstrating that the polymorph has advantages over previously known forms, such as improved chemical stability, more favourable hygroscopicity, better manufacturability, or improved dissolution performance. An XRPD characterisation establishing the uniqueness of the form is a standard element of a polymorph patent application.
Salt Forms
A novel pharmaceutical salt is patentable if it is not described in the prior art and has demonstrated physicochemical advantages. The patent should describe the process for preparing the salt, its analytical characterisation, and the evidence for its advantages. Salt patents have a long history in pharmaceutical IP, and the prior art landscape for common APIs is often dense, making thorough prior art searching an important early step.
Co-Crystals
The patentability of pharmaceutical co-crystals has been established through a series of patent office decisions and court cases in major jurisdictions over the past fifteen years. A novel co-crystal with demonstrable advantages, supported by characterisation data and evidence of the co-crystal nature of the material, is a patentable entity in most jurisdictions. The regulatory status of the coformer, whether it is a GRAS substance or an approved excipient, is relevant to patentability arguments in some cases.
IP Strategy Considerations by Solid Form Type
| Form Type | IP Opportunity | Key Evidence Required | Timing Consideration |
| Polymorph | New crystal form with demonstrated stability or performance advantage | XRPD characterisation; stability comparison to other known forms | File before public disclosure; prior art search essential |
| Pharmaceutical salt | Novel counterion combination with physicochemical advantages | Characterisation of salt; solubility/stability comparison to free form | Screen broadly; file on most promising forms |
| Co-crystal | Non-ionic multicomponent crystal with measurable advantage | Crystal structure confirmation; coformer identification; comparative data | Growing patent landscape; freedom to operate analysis important |
| Amorphous dispersion | Novel polymer-drug combination or process for preparation | Characterisation of dispersion; stability and dissolution data | Process patents may offer longer-term protection than form patents |
The Risk of Not Screening Thoroughly
The IP risk of incomplete solid state screening runs in both directions. If your development team works with the first crystal form synthesised and a competitor later patents a more stable polymorph, you may face freedom-to-operate issues when you move to commercial manufacturing. Conversely, if you do not identify and protect novel forms early, you risk a competitor doing so and establishing a blocking position on what you might eventually want to use as your commercial form.
Thorough solid state screening, conducted systematically with a combined scientific and IP lens, is the most effective way to both secure your own IP position and establish freedom to operate in your intended commercial form.
How Ardena Supports Solid Form IP Strategy
Ardena’s solid state research team in Ghent conducts polymorph, salt, and co-crystal screening programmes designed to generate data of the quality and scope needed to support patent applications. The team is experienced in structuring screening work to systematically explore the solid form landscape and in generating the characterisation data, including XRPD, DSC, TGA, and comparative physicochemical data, that patent attorneys need to prosecute a strong application.
Ardena works with clients and their patent counsel to ensure that the timing of screening work, the documentation of findings, and the structure of the characterisation data package all support the IP strategy alongside the development programme.
Related: Solid State Screening: Finding the Optimal Crystal Form | Co-Crystals vs. Salts: Which Is Right for Your API?
Build Your Solid Form IP Strategy with Ardena
If you want to understand the IP landscape for your molecule’s solid forms, or design a screening programme that generates patentable data, our team in Ghent is ready to discuss your programme.
