Section 3 explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
Section 3(d) is the clause that most often decides pharmaceutical and chemical applications. Paragraph 09.03.05.04 of the Manual explains what the clause excludes, how the Explanation treats derivatives of a known substance, what the Office expects the specification to say about efficacy, and what the Supreme Court said in the Novartis case as cited there.
The Office does not treat as an invention a new form of a known substance unless it shows enhanced known efficacy, nor a new property or new use of a known substance, nor the use of a known process, machine or apparatus unless it yields a new product or uses at least one new reactant. Salts, esters, polymorphs and other derivatives count as the same substance unless they differ significantly in properties with regard to efficacy. The Manual is the Patent Office's guidance and does not have the force of law; the Patents Act, 1970 and the Patents Rules, 2003 as now in force prevail.
Check the current Manual on ipindia.gov.in. For the overview, see section 3(d) and pharma patents in India and section 3(d) and evergreening. If an objection under this clause has reached you, our patent objection reply service can help.
What the clause excludes (09.03.05.04)
The Manual lists four exclusions:
- the mere discovery of a new form of a known substance that does not result in enhancement of the known efficacy of that substance;
- the mere discovery of any new property of a known substance;
- the mere discovery of a new use for a known substance; and
- the mere use of a known process, machine or apparatus, unless the known process results in a new product or employs at least one new reactant.
The Explanation says that salts, esters, ethers, polymorphs, metabolites, pure form, particle size, isomers, mixtures of isomers, complexes, combinations and other derivatives of a known substance are to be treated as the same substance, unless they differ significantly in properties with regard to efficacy.
What the Office expects the applicant to show
The Manual says the examiner investigates case by case what constitutes a difference in properties with regard to efficacy. The complete specification must bring out clearly and categorically, in the description, how the claimed subject matter differs significantly in properties with regard to efficacy from the known substance, at the time of filing, or subsequently by amendment of the specification under section 59.
That sentence has two practical consequences. First, put the comparative efficacy data in the application as filed. Second, if the data come later, they must still be supported by what the specification discloses and can be brought in only through an amendment allowed by the Act.
What the Manual cites from the Supreme Court
The Manual cites Novartis AG v. Union of India, as cited in the Manual, and reports the Court's reading of section 3(d) in these terms, in outline:
- the added portion of the clause sets a second tier of qualifying standards for chemical and pharmaceutical substances, keeping the door open for genuine inventions while checking repetitive patenting or extension of the patent term on spurious grounds;
- in the case of medicines, efficacy means therapeutic efficacy, and physico-chemical properties do not meet that requirement;
- applicants must prove an increase in therapeutic efficacy; increased bioavailability alone may not lead to enhanced therapeutic efficacy, and enhanced efficacy must be specifically claimed and established by research data; and
- in the case before the Court, properties such as flow, thermodynamic stability and lower hygroscopicity of a crystalline form could not be taken into account for the section 3(d) test because they had nothing to do with therapeutic efficacy.
For the Pharmaceutical Guidelines' own treatment, see paragraph 10 of the 2014 Pharmaceutical Guidelines and the 2013 Biotechnology Guidelines on section 3(b), (c), (d) and (e).
How the objection is framed and answered
| Examiner's objection | What the applicant shows |
|---|---|
| The claimed polymorph, salt or ester is a derivative of the known substance | Data in the specification showing a significant difference in efficacy against the known substance |
| The data show only physico-chemical advantages | Therapeutic efficacy data; the Manual, citing Novartis, says physico-chemical properties alone do not count for medicines |
| Bioavailability is improved but efficacy is not shown | Research data showing the enhanced therapeutic efficacy specifically claimed |
| The claim is a new use of a known compound | A claim to a new product or a process with a new reactant or product, if the specification supports it |
| The claim is to a known process | A new product from the process, or at least one new reactant |
| The comparison is with the wrong substance | Compare with the known substance named in the prior art, at the filing date |
The reply therefore needs three things: the known substance identified; a measured, comparable property tied to the efficacy of that substance; and a pointer to where the specification states it.
A checklist for filing
| Step | Check |
|---|---|
| 1 | Name the known substance and the closest prior art disclosing it |
| 2 | State the known efficacy, such as the therapeutic effect |
| 3 | Put comparative data in the description at filing |
| 4 | Separate therapeutic efficacy data from physico-chemical data |
| 5 | Claim the specific form and the efficacy it shows |
| 6 | If amending later under section 59, keep within what the specification supports |
Worked example
Mahajan Pharma Ltd files an application for a crystalline form of a known antihypertensive salt. The examiner objects under section 3(d), noting that the form is a polymorph of a known substance. The specification reports improved powder flow and storage stability, but no therapeutic comparison. The reply argues those properties are beneficial but, applying the Novartis reasoning the Manual cites, they do not show enhanced therapeutic efficacy; the company then points to a pharmacokinetic and efficacy study in the specification as filed. If the application had contained no such data, the company would be left with the amendment route under section 59, which only works where the specification supports the data.
Need help with a section 3(d) objection?
These objections are decided on data. Our patent objection reply team can review the specification, identify the efficacy data already on file and prepare the reply and any amendment within the Act.
Key takeaways
- A new form, new property, new use or use of a known process is not an invention unless the exceptions in section 3(d) are met.
- Derivatives are the same substance unless they differ significantly in properties with regard to efficacy.
- For medicines, the Manual (citing Novartis) says efficacy means therapeutic efficacy; physico-chemical advantages alone do not count.
- State the efficacy difference clearly in the description at filing; later amendment is only under section 59.
- The Act and Rules as now in force prevail over the Manual.
Read next
- Chapter 9: section 3(a), (b), (c), (e) and (f)
- Pharmaceutical Guidelines 2014, paragraph 10: section 3(d)
- Biotechnology Guidelines 2013: section 3(b), (c), (d) and (e)
- Section 3(d) and pharma patents in India
Disclaimer: Based on the manuals and guidelines published by the Office of the Controller General of Patents, Designs and Trade Marks that are named in the article, as consulted on 4 October 2026. They are guidance and do not have the force of law; the Patents Act, 1970 and the Patents Rules, 2003 as amended (including the 2024 amendment rules) prevail, and the current versions on ipindia.gov.in should be checked. This article is general information, not legal advice; check the official text before acting.