Indian position about patent eligibility of the product of nature still remains in the realms of elusive debates for want any judicial precedence on the subject in India. Section 2 (1) (j) defines that invention means any new product or new process without differentiating between ‘product of nature’ or ‘man made products’. However, Section 3(c) clearly point out that discovery of living things or non- living substances are not patentable inventions. In second limb word ‘mere’ conspicuously is omitted to perhaps leave a room for invention relating to substances occurring in nature which are not discovered but extracted or removed from the nature not occurring freely in nature. Here structure similarity of the pure form with natural form at times creates patentability hurdle of being new as compared to naturally existing one. Its usefulness however, can make it cross the patentability line. There is not inherent stigma or bias on patentability on materials derived or obtained from nature. Patent Law clearly distinguish between finding new substances in nature and making material existing in nature available in a useable form.

Pure vs Impure

        The earliest such material that was subject matter of dispute in US was ‘Prostaglandins’ [US 3,069,322] which has wide variety of application in physiological process because of its inherent similar nature like hormones. The claim in this case was for compounds sufficiently pure to give an ideal curve on partition chromatography. The Patent Office Board of Appeals affirming the examiner's rejection of such claims for ‘PGE Type Compounds’ lacking in novelty [as the claimed compounds are naturally occurring] did not find favour with  U.S. Court of Customs and Patent Appeals (CCPA) [427 F.2d 1394 (C.C.P.A. 1970)]. According to CCPA “Failing to find pure PGE2 and PGE3 described in the Bergstrom publication, the board in turn seems to have premised its decision on the inherency of an impure form of PGE2 and PGE3 in products resulting from certain procedures”, without even looking at “whether the claimed pure materials are novel as compared with the less pure materials of the reference.” CCPA observed that “It seems to us that the answer to that question is self-evident: by definition a pure materials necessarily differ from less pure or impure materials and, if the latter are the only ones existing and available as a standard of reference, as seems to be the situation here, perforce the "pure" materials are "new" with respect to them.”  Webster's New International Dictionary, also defines "pure" as "Separate from all heterogeneous or extraneous matter; free from mixture or combination and "Impure" is defined as "not pure; *****mixed or impregnated with something extraneous * * *." It makes a clear distinction between the two for the purpose of novelty. As the pure material per se did not exist in nature the pure material so obtained was considered sufficiently new to cross the line of novelty. In plain words the novelty is not destroyed when the substance of nature is produced in pure or more useful form. Mostly such patents include claims for isolation and purification as well. However, where patent is granted for product it is limited to the isolated and purified form only not for the form occurring in the nature.

New form of known substance

        The question before the examiner today is how to distinguish ‘product of nature’ from ‘products derived from nature’. First he must shed the inherency bias to arrive at the decision on novelty as every such product of nature is not exiting in free state and in useful form. In Indian context mere discovery of new form of known substance if it is a product of nature hit another hurdle of section 3 (d). The question which is required to be answered here is whether the new form of a known substance results in the enhancement of the known efficacy of that substance. If we apply explanation particularly to the  ‘pure form’ the applicant is expected to give clear and convincing evidence in terms of difference significantly in properties with regard to efficacy. The difference in form may cross the line of novelty but its improvement in efficacy only can beat the threshold of patentability under section 3 (d). Supreme court view on efficacy is loud and clear that  “The amended portion of section 3(d) clearly sets up a second tier of qualifying standards for chemical substances/pharmaceutical products in order to leave the door open for true and genuine inventions but, at the same time, to check any attempt at repetitive patenting or extension of the patent term on spurious grounds” .Thus Supreme court clear the mist around patentability of new form of known substance where such form prove to be have  improvement in efficacy. Here the efficacy as explained by the court should in the context of the pharmaceutical patenting be understood as “therapeutic efficacy”. Explaining the meaning of the term efficacy Supreme Court ruled that “Efficacy means “the ability to produce a desired or intended result”. Application of this in practice would clearly mandates that test of efficacy in the context of Section 3(d) would be different, depending upon the result the product under consideration is desired or intended to produce. Thus it would depend upon the function, utility or the purpose of the product under consideration.  If we see its application on pure form of prostaglandins it would mean that in a claims relating to substance meant to cure a disease, the test of efficacy can only be “therapeutic efficacy”. If it is proved that isolated pure prostaglandin is better in efficacy as compared to prostaglandins naturally occurring in the fluids, it would perhaps qualify as patentable under the Indian Law.

Obviousness and substantially pure form

        It not true that every substantially pure form of a natural product would have a free ride on patent grants. The product so claimed must also cross the obviousness threshold to pass the patent grant. Let’s take another example of substantially pure form US 6,500,829 patent dispute In Spectrum Pharmaceuticals, Inc., v. Sandoz Inc., [Fed. Cir. Oct. 2, 2015]. The ’829 patent is directed to pharmaceutical compositions of substantially pure levoleucovorin. The  Court in this case ruled that claims of a mixture comprising at least 92% of the (6S) isomer of leucovorin are obvious when both the 50/50 mixture of isomers and the pure (6S) isomer were known in the art. There was no evidence court observed to indicate that claimed mixture “possessed unexpected advantages over the prior art pure material” so as to overcome obviousness.” Another aspect which went against the patent was evidence which clearly demonstrated that purified (6S) leucovorin and a 50/50 mixture of isomers are clinically interchangeable. This case clearly demonstrates that possibility of getting a patent or defending it rests on proving its efficacy over the known product. Patent act in Indian context codified this thin line under section 3 (d) to keep obvious or clinically interchangeable products under non patentable subject matter to put a check on evergreening of a patent.

Recent trends – looking forward

        In USA and even in other jurisdiction the scope of getting patent on product of nature has not changed substantially since the first pure form patent was granted. For example in May 2019 US district court in a pure form cannabinoids case denied Pure Hemp’s Early Motion for Partial Summary Judgment on the  claims of UCANN's U.S. Patent No. 9,730,911 for  "[a] liquid cannabinoid formulation, wherein at least 95% of the total cannabinoids is" a specified cannabinoid (CBD or THC or a combination). The court did not in fact deviated from precedent for purified natural products thus leaving enough room for grant of such patents. In Indian context if the product of nature substantially differs from the product which is result of handiwork of the inventor he may cross the 3(d) line directed to one of those patent-ineligible concepts such as pure form. Only requirement in India for such products would be that they are mandated to prove its efficacy over the known product. Therefore, in India purity per se is no guarantee that patent would be granted. However, the claim to a process to isolate a substance occurring in nature and making it available in pure form is patentable. Where the claims for isolation of product of nature or substance occurring in nature is characterised by its process or by structure it would also qualify as patent eligible subject matter. In such situation the claims may include patenting of product of nature per se. Does this mean that section 3 (c) limitations are merely to restrict the patenting of discoveries which are handiwork of nature? However, in absence of precedence subject matter eligibility would perhaps remain the core question on patentability of pure form. Though the Supreme Court decisions in Novartis did raise the hurdle bar higher to meet subject matter eligibility for new forms yet the more efficacious forms would continue to receive patents in India.