PURIFIED FORMS OF COMPOUNDS OR MATERIALS - Patent law

From our earlier discussions on novelty, you will recall that a claim could be anticipate dif and only if each and every element was present in a prior art reference. Some of the earlier claim examples we analyzed included claims to compounds where the claimed compound needed to be present with a particular purity. If the prior art disclosed that same compound but not in the purified form, the claimed form of that compound is novel. Although of high potential value, most natural products have yet to be isolated or purified, so one area of chemical patent law where purity or related claims are especially important is in the claiming of natural products, including small molecules (e.g., taxol). However, as we learned earlier in our discussion on patentable subject matter, products of nature are one of the categories that cannot be patented—Mother Nature was first to invent. However, a claim to a natural product other than how it is present in nature should be novel. Of course, as we now so well know, novelty alone doesn’t confer patentability, and so it is important to examine USPTO and federal court decisions for opinions relating to the obviousness/non obviousness of purified forms of previously disclosed compounds. As we consider the question of whether a previously known, impure (present in mixture)compound in the prior art makes a later claimed, purer or isolated form of the compound obvious, one needs to consider whether a person or ordinary skill in the art would have a reason to want to purify the prior art mixture; there has to be some indication that one of ordinary skill in the art would be aware of the compound and,further, that one would expect some use or utility for the purified or isolated form.
The second consideration asks if one of ordinary skill in the art would have be enable to carry out the purification even if they were motivated to do so. Remember that obviousness also requires that the prior art provide not only the motivation to make the later claimed invention but also a likelihood that one of ordinary skill in the art would have been successful in doing so. Isolation of complex and/or sensitive materials can be very difficult and the outcome not at all certain. Thus very often a wish to make something happen is a far cry from being able to make it happen,and the art must be able to provide both the wish and the means to make that wish come true.
On the surface, this might all appear somewhat contrary to the immediately preceding section related to the prima facie obviousness of optimization of ranges. One might surmise that claiming a compound in simply a purer form is akin to claiming a different range or amount that was either known in the art or in nature. However, recall that the ranges being optimized in the previously discussed cases were prima facie obvious because they were known to be results effective variables. Thus where one of ordinary skill would know that the variable is results effective and be in the possession of the means to do so, one would possess the motivation and the means to do so. The motivation would be the mechanic’s desire to optimize what is known to get her with a workmanlike ability to manipulate the range. This is in contrast to the generic situations we have described for claiming a more purified form where the natural form was simply not previously known or identified. Or if it were identified,a use for it was not appreciated. Or even if it was identified and a use appreciated, the means to obtain the material might be beyond one of skill in the art. This does not mean that claiming a purified form cannot be prima facie obvious; it means we need to keep in mind the considerations just mentioned when making that assertion.
Our next case, In re Kratz, provides an opportunity to examine the obviousness inquiry as it relates to an applicant’s claimed invention directed to compositions containing a compound already found in the natural state. This case focuses on the purification of compounds responsible for the flavor of strawberries and arose from a reissue application (reissue of U.S. 3,499,769, ultimately reissued as Re. 30,363).The appealed claims of interest are shown below.
13. A process for imparting a strawberry flavor or aroma to a foodstuff which comprises adding thereto from about 0.5 up to about 25 parts per million, based on the weight of said food stuff of a composition consisting essentially of synthetically produced sub stantially pure 2-methyl-2-pentenoic acid.
14. A flavor modifying composition useful in imparting a strawberry flavor to a foodstuff consisting essentially of (i) from 1 to about 20% by weight of said flavoring composition of synthetically produced substantially pure 2-methyl-2-pentenoic acid and (ii) the remainder of said composition being at least one adjuvant for said 2-methyl-2-pentenoicacid, selected from the group consisting of geraniol, ethyl methyl phenyl glycidate,vanillin, ethyl pelargonate, isoamyl acetate, ethyl butyrate, naphthyl ethyl ether, ethylacetate, isoamyl butyrate, diacetyl, cinnamic acid, oil of cinnamon and decalactone. (The claim numbers assigned correspond to the numbers in the reissue patent.)
The examiner rejected the claims as obvious based primarily on two references that confirmed that 2-methyl-2-pentenoic acid was a known component of strawberries.
One of the references simply identified the material via an analytical procedure without physically isolating the material, and the other reference was the applicant’sown technical report. The cited references were not listed as prior art per se, but rather as evidence of scientific fact that the strawberry component 2-methyl-2-pentenoicacid was found naturally in strawberries. The USPTO examiner rejected the claims,stating:
The claimed compound is a natural constituent of strawberries. The analysis of natural constituents of foods is now conventional as it was at the time of the filing of this application. To analyze strawberries, identify the claimed constituent and use it in its obvious environment, e.g. food or flavoring, would be obvious to the ordinary worker in the art. Attention is drawn to the Kratz paper, cited above, which sets forth that invent or Kratz did not do anything more than analyze strawberries so that information derived from the analysis could be used to improve the imitation strawberry flavor. There is nothing in the record to indicate unobvious subject matter. On the contrary, the record establishes that applicants have done no more than do the expected analysis for the expected objective. The recitation in the claims of the use of the “substantially pure”or “synthetically produced substantially pure” are not seen to influence the conclusions reached. The synthetic or substantially pure compound would be obvious over the natural constituent.
After failing to overcome the examiner’s rejection, the applicants appealed to the USPTO Board of Appeals. The applicants argued that the required element of their claims, 2-methyl-2-pentenoic acid, was isolated only after a very lengthy and arduous analysis of the strawberries, which required the assistance of “advanced”analytical techniques including nuclear magnetic resonance, gas chromatography, and infrared spectroscopy The applicants further argued that strawberries contain a wide variety of components, and it was unexpected to find that one compound could lend the fragrance and taste of the strawberry. A supporting declaration was also submitted by the applicants that purported to demonstrate unexpected superiority of flavorings when treated with just a small amount of the isolated, claimed material.
The declaration also was relied on to show the low levels of 2-methyl-2-pentenoic acidin natural strawberries versus the levels required in the claims. However, the Board agreed with the examiner’s position and discounted the difficulty of the separation as well as the sophistication of the instrumentation used to assist in that endeavor,arguing that these conditions were not contributive to patentability. The Board also pointed out that the compound itself was not novel to this application but had been previously prepared.
The applicants then appealed to the CCPA where they had better luck. The CCPA began its written opinion by reminding the USPTO Appeal Board that it was impermissible to negate inventiveness based on the method used by the applicants for discovering their invention. Second, they noted that the obviousness determination must be based on a comparison of the claimed matter and the prior art. As such, the prior art at the time of the invention was the “natural strawberry and its attendant taste.” From this, there was no basis for selecting the claimed compound and using it in compositions as claimed by the applicants. But the court did not stop there. Even if the components of the strawberry were identified in the prior art as components of strawberries, such a list would not direct a person to any particular compound for use in any particular purpose. Pointing to the requirement that obviousness require sat least at least some predictability, the court considered that even if 2-methyl-2-pentenoic acid was known in the art as a strawberry component, the prior art must provide some for see ability that the component would be “a significant strawberry flavor ingredient.” The CCPA thus concluded the claims were patentable.In the instant case, the USPTO appeared to assert an obviousness rejection based on how the discovery itself was made, rather than giving weight to the failure of the priorart to motivate one to specifically arrive at the claimed invention. In effect, the USPTO took the position that the isolation, extraction, identification and use for compositions or methods was essentially a technical endeavor lacking in inventive insight. This can be an easy mistake to make, as we all carry ideas that confuse inventive insight with the requirement of invention vis-a`-vis obviousness. This distinction is of such importance that the 35 U.S.C. §103 statute itself reminds us that “patentability shall not be negatived by the manner in which the invention was made.” Focusing on the claimed substance itself, the Court could have asked: If it was not known that 2-  methyl-2-pentenoic acid was in strawberries (or any other flavorful substance), what would have motivated one of ordinary skill to claim that very same compound in a flavor-enhancing composition? Alternatively, even if it were known that 2-methyl-2-pentenoic acid is a component of strawberries, why would one of ordinary skill in the art have thought that it would lend a strawberry flavor and, furthermore,what sort of composition would such a flavor have been useful in? Finally, the fact that the compound itself was known in the art (but not as a strawberry component)would not motivate one to provide for a flavor-enhancing composition containing the same compound. There are literally many millions of organic compounds that are known in the art. What would motivate one to test this particular compound, out of the many millions, for this particular purpose? The disclosure in the art, absent an accompanying utility is not considered sufficient motivation to include the compound in a composition with a demonstrated utility. In the instant case, not only was the compound first isolated by the inventors from strawberries, they also found utility for that compound. Furthermore, they provided for compositions useful for specific purposes where those compositions included concentrations of the material that were not the same as they existed in the natural state, composition ratios and amounts that would be capable of imparting the strawberry flavor to foods. The CCPA was able to divorce the routine nature of the method used to find 2-methyl-2-pentenoic acid from the non obviousness of the 2-methyl-2-pentenoic acid as claimed.
Although the case just presented focused on the isolation of molecules and proteins from complex mixtures found or derived from nature, the same principles can also apply even where the prior art is not what is found in nature but rather compounds previously prepared by man, but only in a different, less pure form. Such was the situation in the next case, In re Cofer, arising from an appeal to the CCPA of a USPTO rejection of the two claims shown here:
1. As a manufacture, free-flowing crystals of 2,2-bis(2,3-epoxypropoxyphenyl)propane.
8. As a manufacture, free-flowing crystals of substantially pure 2,2-bis(2,3-
epoxypropoxyphenyl)propane characterized by a sharp melting point of about 43.5degrees C, a weight to epoxide ratio of about 170 grams per equivalent epoxide, total chlorine content of less than 0.1 percent by weight, saponifiable chlorine content of less than 0.01 percent by weight, total hydroxyl content of less than 0.01 gram equivalents per 100 rams, each, and a viscosity, when a super cooled liquid, of less than about 40poises at 25 degrees C.
The claimed compound of the invention is produced by the reaction of epichlorohydrinand bisphenol A and was well known in the art and was also known to be useful in the preparation of thermosetting epoxy resins. The claim preamble “As a manufacture . . .,” is equivalent to saying “As a product of manufacture . . .,” which in turn means that these two claims are compound claims. Although the compound was well known in the literature, it was reported in the context where it made up to70% to 90% of a complex liquid mixture. According to the applicant’s patent application specification, no method had been described that would allow the production of pure 2,2-bis-[(4)-2,3-epoxypropoxyphenyl]propane directly from a reaction mixture.Prior attempts to recover the product of the reaction resulted in, at best, a viscous liquid that adversely affected the usefulness of the product. In contrast to the prior art,applicant’s methods resulted in material of sufficient purity that the compound was isolated as a free-flowing, crystalline powder. This material could be easily handled and allegedly could be used to prepare epoxy resins equal or superior to the liquid material prepared previously.
In the course of rejecting the claimed crystalline material of applicant’s invention,the examiner concluded that simply claiming this compound in a more pure and different physical state was obvious. The USPTO Board of Patent Appeals upheld the examiner’s rejection and attempted to lay down what looked like a broad, per serule on the issue, saying, “merely changing the form, purity or another characteristic of an old product, the utility remaining the same as that for an old product, does not render the claimed product patentable.” However, the CCPA soundly rejected the Board’s reasoning, noting that: “Merely stating a compound or composition is obvious, without factual support, is not sufficient.” In reversing the Board’s decision, the court reminded the Board that the obviousness analysis must consider the subject matter as a whole. The invention as a whole includes the fact that the claimed compound was a solid, which the court found was not suggested in the art and furthermore, the court held that those of ordinary skill in the art would not have known how to obtain such crystals. As we have discussed previously, the prior art must be enabled. In this case, the Court found that the prior art did not describe the claimed compound as a pure crystalline solid nor would it have enabled its production.
Accordingly, they reversed the USPTO obviousness rejections to the two claims at issue.
In summary, at its core the obviousness determination is subjective in nature.What would be obvious to one person might not be to another. To make the inquiry more objective, techniques are used such as asking the fact-finder to attempt to stand in the shoes of one of ordinary skill in the art at the time of the invention and judge the inventiveness based on that criterion. But in reality, this is difficult to do because,ultimately, if the invention is not explicitly disclosed in the art, then one can only at best surmise what one of ordinary skill would or would n’t do in any given situation.
Putting oneself in another’s shoes is difficult enough under any circumstance but probably even more so when one is asking the fact-finder to put himself in the position of a person having ordinary skill in an art of which the fact-finder may in fact know little or nothing about. Further complicating matters is the tendency for humans to engage in hindsight reconstruction, unable to fully appreciate the many choices an inventor had when he decided to go the particular way that he ultimately did choose.
In hindsight, good choices often seem obvious but when confronted with the thicket of choices available at the time of the invention, the inventor does not have the benefit of his own success to guide him. Perhaps in answer to these myriad difficulties,the court in Graham set out to create objective criteria for defining obviousness but left available numerous ways that non obviousness might be demonstrated through secondary considerations. These considerations provide proxies that can allow one to draw inferences regarding the non obviousness of the invention itself. The definition of obviousness remains far from set in stone, as exemplified by the recent Supreme Court opinion in KSR v. Telesales, and we should content ourselves to accept a certain amount of uncertainty no matter how much we might wish otherwise.


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