When pharmaceutical companies develop a new drug, there are two types of patents that they most commonly apply for:
Active Ingredient Patents
An active ingredient patent, or active pharmaceutical ingredient patent (API), is probably the strongest means of protecting a newly invented drug, as active ingredient patents cover the structural formula of the drug. This patent applies to any form of the drug, whether it’s formulated as a pill, capsule, cream, liquid, etc. If the molecule is present in a product, then the patent applies. This is a rather iron-clad patent that prevents competitors from offering generic versions of a drug in any form until the expiration of the patent.
Active ingredient patents are also known as composition of matter patent, compound patent and product patent and sometimes are interchangeably used. However, these patents may also be applied to a Markush structure, in which a core molecular structure with optional structures that can be attached to it to produce variations that are functionally equivalent and thus covering more than one structure.
Formulation Patents
It’s quite common for pharmaceutical companies to take long-known compounds and put a new spin on them. For the purposes of formulation patents, this typically takes the form of restructuring a chemical molecule or combining it with other ingredients in order to get it to behave differently while still delivering a benefit. This can be an effective means of extending the lifespan of an aging but popular product.
For instance, the drug amphetamine was discovered by a Romanian chemist 130 years ago, in 1887. Its obvious stimulant effects made it a popular performance enhancer, and it was also marketed for a variety of other uses, such as nasal congestion. However, many decades later, pharmaceutical companies were still finding new ways to reformulate it and adjust its behavior in order to tweak its effects and create new applications.
In 1996, Richwood Pharmaceuticals began selling the hugely successful ADHD drug Adderall, which was a formulation consisting of four differently structured amphetamine salts. Despite being based on a drug that was more than a century old—the amphetamine salts in question were also long since in the public domain—but because Adderall consisted of a novel formulation, it was eligible for formulation patent protection. A few years later, a new formulation of the drug, Adderall XR which slowed down the rate at which the drug was metabolized, was also granted a new formulation patent despite being almost identical to the original Adderall formulation.
It can be very tricky to determine what patent type is best-suited to a particular pharmaceutical product, which is why it’s advisable to consult with an experienced patent lawyer before proceeding with a patent claim.