Can an admixture of known substances qualify the requirement of Inventive step?

Question:  Can an improvement or process involving an admixture of known substances be considered to involve an inventive step?  In other words can an improvement or a process involving an admixture of known substances qualify the test of satisfying inventive step requirement?

Answer: There are two sections that we need to consider before we can answer this question, because the questioner has posed a question asking whether an admixture of known substances is patentable especially whether it can satisfy the requirement of an inventive step.

When you mention known substances, immediately the wordings of section 3d is attracted and when you mention admixture the wording of section 3e is attracted. So this question has to be answered by factoring the requirements in section 3d and also the requirements in section 3e.

Let’s take section 3d first. Section 3d can be divided into 3 parts, part 1 deals with new form of a known substance where in the explanation talks about mixtures of known substances so it would attract this part, and as you would know part 1 of the section 3d is a hurdle that can be overcome its not an absolute bar. If you are able to show enhanced efficacy, the courts have now understood efficacy as therapeutic efficacy, if enhanced efficacy can be demonstrated by the applicant then the applicant is entitled to the grant of a patent. So we understand the bar in section 3d part 1 which deals with new forms of known substances including admixture of known substances, as a bar that can be overcome. So you demonstrate something like enhanced efficacy you can get over the bar.

Section 3d also has a second part to it and also a third part. Part 2 deals with properties and new uses of known substances that’s an absolute bar, no matter what you demonstrate if your patent application covers a new property or a new use of a known substance there is an absolute bar. You cannot demonstrate efficacy and get over it and part 3 of section 3d deals with use of new substances involving a new process, that’s not relevant for this question. So under 3d an admixture of known substances will come under the explanation of section 3d wherein they talk about mixtures of known substances as well so if an admixture of known substances has to get over the bar of section 3d then yes the applicant has to demonstrate that there is enhanced therapeutic efficacy, we say therapeutic because of the Supreme Court ruling in the Novartis case which has equated efficacy in the case of drugs to therapeutic efficacy. Now there is another bar under section 3e which talks about the bar is on mere admixture of known substances will not be granted a patent. Again the question is whether it will be treated as involving an inventive step. Inventive step is a different requirement to look at 3d and 3e they are not requirements of inventive steps, they are actually exceptions to patentability. So one could argue that the exceptions to patentability have to be satisfied and only when you satisfy the exceptions do you become patentable subject matter and once you are considered as patentable subject matter will the test of patentability be applied and that is where the inventive step test would come in.

Now let us understand the question, as to whether an admixture of known substances can be patented, inventive step is just a criteria, let us look at the bar to patenting, which is there in section 3d and 3e. As mentioned in 3d, the critical part is to demonstrate efficacy, when it comes to Section 3e, the Act clearly states that mere admixtures will not be granted a patent, but again in practice especially if you look at the patent manual which the patent office has revised and released in 2019, we had an earlier manual in 2011 both these manuals say that in the case of 3e, if the applicant is able to demonstrate a synergistic effect when an admixture, an admixture is like a mixture of different substances, when you make an admixture it is treated as a mixture of known substances, but if the admixture exhibits a synergistic effect, a synergistic effect can be understood as a simple case of 2 + 2 being 5 or the sum of the parts being greater than the whole. Now that can be patented provided the synergistic effect is demonstrated.

So, yes, admixture of known substances can be patented provided they get over the bar under Section 3d by demonstrating enhanced efficacy and they get over the bar under Section 3e where synergistic effect is also demonstrated.

Get free updates on Patent Case Laws, Patent Drafting Tips, Patent related Q&A, and offers in your inbox

Try our free newsletter.

Want to Learn Patent Law?

The most in-depth online course in Patent Law in India at the most affordable price of just Rs.199 per month.


Firstly it changed the approach of looking at the subject. At the first instance bare act seemed dry. The lecture series actually explained 'why' of the topic and statutes. Which helped in understanding the way the things are .

Nachiket Galgali

To receive updates on Patent Case Laws, Patent Articles, Patent Q&A & more in your inbox, subscribe to our free newsletter.