Understanding Patent Categories: Navigating the Maze of Product and Process Inventions

When we talk about patents, the conversation usually circles around a single question: what exactly can be patented? The answer is not as straightforward as it seems. Under the TRIPS Agreement, patents must be available for any invention – whether a product or a process – in all fields of technology, provided the invention is new, involves an inventive step, and is capable of industrial application. But that broad mandate quickly runs into national laws, moral considerations, and public health imperatives that carve out significant exceptions. For Indian law students and practitioners, understanding the categories of invention – and where each category stands under the Patents Act, 1970 – is foundational to navigating the entire patent system.

The two fundamental categories: products and processes 🔗

At its core, patent law divides all inventions into two broad categories: product inventions and process inventions. This distinction is not merely academic – it has direct legal consequences for what rights the patentee holds and how infringement is determined.

A product patent protects a tangible thing – a machine, a chemical compound, a device, or a new material. The patent owner can stop anyone from making, using, selling, or importing that product without authorization, regardless of the process used to make it. A process patent, on the other hand, protects a method or technique – a manufacturing process, a chemical reaction, or an industrial procedure. Here, the protection is narrower: only the specific method is covered, not necessarily the end product.

Section 2(j) of the Patents Act, 1970 defines an invention as “a new product or process involving an inventive step and capable of industrial application.” This definition itself recognizes both categories as eligible subject matter. Historically, India only permitted process patents for drugs, food, and chemicals – a policy that enabled Indian companies to reverse-engineer branded medicines and supply affordable generics globally. The 2005 amendment, brought in to comply with TRIPS, introduced full product patent protection across all technological fields, fundamentally reshaping pharmaceutical and chemical innovation in India.

Chemical inventions and the unique hurdle of Section 3(d) 🔗

Chemical patents are among the most commercially significant, particularly in the pharmaceutical and agrochemical sectors. They cover new compounds, compositions, formulations, and chemical processes. In most jurisdictions, a new chemical entity with a distinct molecular structure and demonstrable utility can qualify for a product patent.

India largely follows this framework – but with a critical addition. Section 3(d) of the Patents Act imposes a higher patentability bar specifically for pharmaceutical substances. It bars patents on new forms of known substances – such as polymorphs, salts, esters, or enantiomers – unless the applicant can demonstrate a significantly enhanced efficacy compared to the known compound. This provision was deliberately designed to prevent “evergreening”, the practice of obtaining fresh patent terms through minor chemical modifications without meaningful therapeutic improvement.

The landmark case of Novartis AG v. Union of India (2013) before the Supreme Court remains the definitive judicial statement on Section 3(d). The Court upheld the rejection of Novartis’s patent for the beta-crystalline form of imatinib mesylate (marketed as Gleevec), ruling that improved bioavailability alone does not constitute enhanced “efficacy” for the purposes of the provision. Section 3(d) was implemented explicitly to address concerns that additional patents on existing substances could extend market exclusivity and delay generic competition.

The provision has also been applied in other notable instances. In 2015, the Indian Patent Office initially used Section 3(d) to reject Gilead’s patent on sofosbuvir, a key Hepatitis C treatment, treating the compound as a derivative of a known molecule – though Gilead ultimately prevailed on appeal. The practical message for inventors is clear: in India, new uses or new forms of known pharmaceutical compounds face a substantially higher bar than in the US or Europe, where novelty and non-obviousness alone generally suffice.

Biotechnological inventions: where biology meets the boundary 🔗

Biotechnology presents some of the most contested patent questions globally. In India, the patentability of biotech inventions is shaped by an interplay of Sections 3(c) and 3(j) of the Patents Act.

Section 3(c) excludes the mere discovery of any living thing or non-living substance occurring in nature. This means an isolated naturally occurring gene sequence, a naturally occurring protein, or a wild-type microorganism cannot be patented – they are discoveries, not inventions. However, a genetically modified gene sequence or microorganism that results from human technical intervention can be patented, provided it meets the standard criteria of novelty, inventive step, and industrial application. The key distinction is between finding something that already exists in nature and creating something new through deliberate scientific effort.

Section 3(j) goes further, excluding plants and animals in whole or any part thereof – including seeds, varieties, and species – as well as essentially biological processes for their production or propagation. This provision follows Article 27.3(b) of TRIPS, which allows member countries to exclude plants and animals from patentability. India has gone slightly beyond TRIPS by explicitly mentioning seeds in the exclusion. Plant varieties are instead protected under the Protection of Plant Varieties and Farmers’ Rights Act, 2001, a sui generis system that balances breeders’ rights with farmers’ rights.

What can be patented in biotechnology? Processes for producing transgenic organisms (where human technical intervention is substantial), genetically modified microorganisms, recombinant proteins, novel DNA constructs, vectors, and diagnostic kits are all potentially patentable subject matter. The practical difficulty lies in demonstrating that the claimed invention is not a mere discovery of something occurring in nature, and that there is genuine technical human intervention behind it.

Mechanical inventions: the most straightforward category 🔗

Mechanical patents cover devices, machines, tools, structures, and mechanical processes. This category – which encompasses everything from industrial equipment and automotive components to consumer products and construction technology – tends to be the most straightforward area of patent law in India. Mechanical inventions typically have clear physical embodiments and demonstrable functional improvements, making it easier to satisfy the requirements of novelty, inventive step, and industrial applicability.

There are no category-specific restrictions on mechanical inventions in the Patents Act comparable to Section 3(d) for pharmaceuticals or Section 3(j) for biological material. An inventor of a new mechanical device or process needs to satisfy the standard three-pronged patentability test and ensure the invention does not fall within the general exclusions under Sections 3 and 4. Section 3(f), for instance, excludes the mere arrangement or rearrangement of known devices where each functions independently in a known way – so combining two existing machines without producing a new technical result will not be patentable.

Mechanical inventions also illustrate the product-process distinction cleanly. A novel machine is a product patent; a novel assembly technique for that machine is a process patent. Both can be filed and both receive 20 years of protection from the date of filing under the Patents Act, 1970.

Software and computer-related inventions: a contested frontier 🔗

Software-related inventions are the most legally complex category, not just in India but globally. Section 3(k) of the Patents Act excludes “a mathematical or business method or a computer program per se or algorithms” from patentability. The operative word is per se – meaning “by itself.” What is not patentable is a computer program in isolation; a computer program that demonstrates a technical effect when combined with hardware may be eligible.

This distinction has been clarified through a series of important judicial decisions. In Ferid Allani v. Union of India (2019), the Delhi High Court held that inventions demonstrating a technical effect or technical contribution are not barred by Section 3(k). The court emphasized that the test is whether the invention produces a real-world technical advancement – not merely automates a business process or encodes an algorithm.

Business methods are not patentable in India under Section 3(k). However, if a business method is implemented through a technically innovative process that offers a technical solution to a technical problem, there is a possibility of acceptance. The focus must be on the how – the technical implementation – not just the what – the business concept.

Comparing jurisdictions reveals significant divergence. The US applies the Alice framework, which asks whether a claim is directed to an abstract idea and, if so, whether it adds “something more” to constitute a patent-eligible application. The European Patent Office (EPO) uses a problem-solution approach focused on technical character. India’s approach under Section 3(k) is closer to the European technical contribution model, though Indian examination often lacks the structured rigor of EPO proceedings. The 2017 Computer Related Inventions (CRI) Guidelines issued by the Indian Patent Office removed the earlier requirement for novel hardware and shifted focus to overall technical contribution – a meaningful liberalization, though significant ambiguity remains in practice.

For startups and technology companies, the practical advice is consistent: frame claims around the technical problem solved and the technical effect produced. Articulate how the software interacts with hardware components to produce a real-world improvement, whether in data processing efficiency, system security, or computational performance. Bare algorithmic claims or business logic descriptions will be rejected.

Methods of treatment: excluded from patentability 🔗

One important exclusion that cuts across multiple invention categories is the prohibition on patenting methods of treatment. Section 3(i) of the Patents Act bars patents on any process for the medicinal, surgical, curative, prophylactic, diagnostic, therapeutic, or other treatment of human beings – and similarly for animals. This exclusion is consistent with Article 27.3(a) of TRIPS, which explicitly permits member states to exclude diagnostic, therapeutic, and surgical methods from patentability.

The rationale is straightforward: medical professionals must be free to use any known diagnostic or therapeutic method in the course of treatment without risk of patent infringement. If surgical techniques or diagnostic protocols could be patented, healthcare delivery would be severely restricted. What remains patentable, however, are the products used in these methods – a novel drug formulation, a surgical instrument with a new design, or a diagnostic kit can all be patented. Section 3(i) does not include surgical, therapeutic, or diagnostic kits, instruments, or apparatus – these remain patentable subject matter. The distinction is between the method of using a tool and the tool itself.

How India compares: territorial variations in patentability 🔗

A recurring theme across all invention categories is that patentability criteria vary significantly by jurisdiction, even within the broad framework set by TRIPS. The Agreement sets minimum standards – member countries retain flexibility to go beyond those minimums in restricting patentability, as India has done with Section 3(d) for pharmaceuticals and Section 3(j) for biological material.

In the United States, new uses for known compounds can generally be patented as “method of treatment” patents, provided they meet novelty and non-obviousness requirements. In India, the same invention faces both the Section 3(d) efficacy hurdle (if it involves a new form of a known compound) and the Section 3(i) bar on methods of treatment. The result is that a compound patent strategy viable in the US may be entirely unusable in India, requiring inventors to rethink their claims and focus on genuinely novel chemical entities or manufacturing processes.

Similarly, in Europe, software inventions with technical character are patentable at the EPO even if the hardware element is not novel – the technical effect of the software is sufficient. India’s approach, while moving in the same direction, still requires a closer demonstrated link between the software and its hardware environment. The lack of clarity in India’s software patenting laws often leaves startups struggling to protect their innovations, leading to potential revenue loss or the need to operate in uncertain legal territory.

For biotechnology, India’s exclusion of plant varieties from patents – and their routing to the PPVFR Act framework – is a deliberate policy choice that differs from countries where plant varieties can be protected through both patent law and sui generis systems simultaneously. The United States, for instance, permits utility patents on plant varieties under broader patent law, giving significantly wider protection.

Why these distinctions matter in practice 🔗

Understanding the category of an invention is not merely a classification exercise – it directly shapes patent strategy. An inventor must first determine whether the invention is a product or a process (or both), identify which specific category it falls into (chemical, mechanical, biotech, software), and then assess which jurisdiction-specific hurdles apply. Filing in multiple countries requires adapting claims to different national standards: what is claimable in the US may need to be reframed entirely for the Indian Patent Office.

India’s patent framework reflects a deliberate policy balance: encourage genuine innovation while preventing the misuse of the patent system to restrict access to medicines, monopolize biological resources, or lock up abstract computational ideas. Provisions like Section 3(d) and Section 3(k) are not flaws in the system – they are intentional features, designed to address the socio-economic realities of a developing country that is simultaneously a major innovator and a major consumer of patented technology.

What do you think? Given that India’s Section 3(d) has been both praised for protecting public health and criticized for discouraging pharmaceutical innovation – do you think the current balance is correctly set, or does it tilt too far in one direction? And as AI-generated inventions become more common, should the definition of patentable subject matter in categories like software and biotechnology be rethought from the ground up?

References

1. https://www.wto.org/english/tratop_e/trips_e/trips_e.htm
2. https://ipindia.gov.in/patents.htm
3. https://www.globalpatentfiling.com/blog/Patentability-criteria-for-an-invention-in-India-
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC5880378/
5. https://www.asiaiplaw.com/article/analysis-of-section-3j-of-the-patents-act-1970
6. https://ppvfra.gov.in/
7. https://www.wipo.int/ip-development/en/agenda/flexibilities/details.jsp?id=8825
8. https://depenning.com/blog/section-3k-compliance-why-inventions-as-instructions-face-patent-challenges/
9. https://www.khuranaandkhurana.com/software-patentability-in-india-a-comparative-legal-analysis
10. https://azamiglobal.com/prosecution-pathway-for-pharma-bio-patents-in-india/
11. https://dexpatent.com/insights/2025/06/18/decoding-section-3k-of-the-indian-patent-act-challenges-and-the-road-ahead-for-software-and-ai-patents/