A chemical patent , pharmaceutical patent or drug patent is a patent for an invention in the chemical or pharmaceuticals industry . Strictly speaking, in most jurisdictions, there are essentially no differences between the legal requirements to obtain a patent for an invention in the chemical or pharmaceutical fields, in comparison to obtaining a patent in the other fields, such as in the mechanical field. A chemical patent or a pharmaceutical patent is therefore not a sui generis right, i.e. a special legal type of patent.
10-520: Chemical patent claims often use generic, Markush structures contained within them, named after the inventor Eugene Markush who won a lawsuit in the US in 1925 to allow such structures to be used in patent claims . These generic structures are used to make the patent claim as broad as possible. In the United States, patents on pharmaceuticals were considered unethical by the medical profession during most of
20-464: A Markush structure is "closed." In other words, the claim language defined by the Markush structure requires selection from a closed group. One way of claiming a Markush structure follows the format: “a chemical selected from the group consisting of A, B, and C” where A, B, and C are alternative chemicals. A claimed Markush structure may be improper if (1) the members of the Markush structure do not share
30-416: A group of related chemical compounds. They are commonly used in chemistry texts and in patent claims . Markush structures are depicted with multiple independently variable groups, such as R groups in which a side chain can have varying structure. This more general depiction of the molecule, versus detailing every atom in the molecule, is used to protect intellectual property. The company which applies for
40-586: A patent makes a general claim for the usage of the molecule without revealing to their competitors the exact molecule for which they are declaring a useful application. Markush structures are named after Eugene A. Markush, founder of the Pharma Chemical Corporation in New Jersey. He was involved in a legal case that set a precedent for generic chemical structure patent filing, Ex parte Markush , 1925 Dec. Comm'r Pat. 126, 127 (1924). The patent filing
50-413: Is obviousness in view of the prior art, which was not considered by the examiner. Nevertheless, the authors conclude, that "having examiners spend more time on the important patents ... is not likely to help much; examiners who get more time to work on important cases now do not do more work, but instead cut and paste their existing work from prior cases." As a better alternative, the authors suggests, that
60-595: The nineteenth-century. Drug patent terms in the US were extended from 17 to 20 years in 1994. Pharmaceutical patents are typically more valuable than any other type of patents, and thus play an essential role in the pharmaceutical industry. There are several reasons for this peculiarity: A 2021 analysis of the most valuable US pharmaceutical patents published in the Orange Book between 2000 and 2018 showed that ca. 25% of these patents end up litigated in courts, but only 26% of these litigated patents are invalidated, well below
70-425: The overall patent invalidation rate of 43%. 94% of these invalidated patents are not the highly innovative “primary’ patents on the active ingredient, but weaker follow-on patents (that claim changes in formulation, dissolution profile, new use), that should have not been allowed by examiners in the first place. Remarkably, the prosecution histories of most of these invalidated patents share striking similarity in having
80-499: The patent owners identify in advance, which patents they intend to list in the Orange Book, and have these patents examined by USPTO's Central Reexamination Unit with a higher level of scrutiny than regular examiners do. Markush structures A Markush structure, Markush group, or a Markush claim is a representation of alternatively useable members. Markush structures are frequently used with chemical structures to indicate
90-444: The same assignees, the same prosecuting attorneys, and the same examiners. Examiners approve litigated patents after having issued fewer office actions than they do with unlitigated patents. For litigated patents it takes approximately five office actions before allowance. In contrast, for the average, it takes approximately eight office actions before an allowance. The main reason for invalidating these weak follow-up patents in courts
100-532: Was US Application 611,637, filed January 9, 1923. Markush was awarded a patent from the US Patent Office for “Pyrazolone Dye and Process of Making the Same” on August 26, 1924. In describing a chemical, a Markush structure allows the patent-holder to list several active/effective structural formulas. In the United States, Markush structures are frequently used to claim alternative components. The correct format for
#400599