Meeting Sufficiency of Disclosure Requirements under the Indian Patent Act, 1970




The Patents Act, 1970 mandates for three prime pre-requisites for the grant of a patent, namely, novelty, inventive step and capable of industrial applicability. Subsequent to the above requirements, an application for the grant of patent must disclose detailed technical information elaborating upon these three pre-requisites in the complete specification, enabling making and using of the claimed invention by a person skilled in the art. In fact, a close look at the format of Form 2 (the Form for filing of complete specification) mentions the requirement of full and particular disclosure by the complete specification. The process of grant of patent for any invention is ‘quid pro quo’ meaning thereby knowledge related to the invention has to be disclosed to the public (quid) and on the other hand, monopoly granted for a term of patent (quo).

The requirement of ‘sufficiency of disclosure’ under the Patents Act, 1970 (hereinafter also referred to as ‘the Act’) has been statutorily laid down in Section 10 of the Act read with Rule 13 of the Indian Patent Rules 2003 (hereinafter referred to as ‘the Rules’) under the head ‘Content of specification’. Particularly, Section 10 (4) of the Act provides that any complete specification shall (a) fully and particularly describe the invention and its operation or use and the method by which it is to be performed; (b) disclose the best method of performing the invention which is known to the applicant and for which he is entitled to claim protection; (c) end with a claim or claims defining the scope of the invention for which protection is claimed; (d) be accompanied by an abstract to provide technical information on the invention.”

The aforementioned requirements under Section 10 (4) of the Act clearly cover the features that should be met any patent application to meet the sufficiency of disclosure i.e. the disclosure of the claimed subject matter has to be sufficient enough to enable a person skilled in the art to perform the invention. For example, in the case of Press Metal Corporation Limited v. Noshir Sorabji Pochkhanawalla[1]’, it was held that: “It is the duty of a patentee to state clearly and distinctly the nature and limits of what he claims.....”.

The concept of sufficient disclosure is not a new concept it was also explained in Farbewerke Hoechst Aktiengesellschaft Vormals Meister Lucius v. Unichem Laboratories[2],’ where the court stated Halsbury’s two branches of insufficiency of description: “(i) the complete specification must describe “an embodiment” of the invention claimed in each of the claims and that the description must be sufficient to enable those in the industry concerned to carry it into effect “without their making further inventions”; and (ii) that the description must be fair, i.e. it must not be unnecessarily difficult to follow.”

In addition to the above, Guidelines for Examination of Patent Applications[3] in the field of pharmaceuticals issued by the Indian Patent Office state:

“Sufficient disclosure of the invention in the patent specification is the consideration for which a patent is granted. While assessing the sufficiency of disclosure, it must be ensured that the best method for performing the invention known to the applicant is described so that the whole subject-matter that is claimed in the claims, and not only a part of it, must be capable of being carried out by a skilled person in the relevant art without the burden of an undue amount of experimentation or application of inventive ingenuity”[4].


".... The description in the specification should contain at least one example or more than one example, covering the full breadth of the invention as claimed, which enable(s) the person skilled in the art to carry out the invention"[5];

The aforementioned reasoning has also been justified by the quasi-judicial authorities in various decisions at the Indian Patent Office and the Intellectual Property Appellate Board (IPAB). For example, in an order dated 12 June, 2012[6], the IPAB, acting on a petition filed by Tata Chemicals, revoked Indian Patent No. 195937 granted to Hindustan Unilever Ltd. (HUL) for the invention of a ‘filter cartridge’ used in HUL’s Pureit brand of water-filtration devices wherein one of the grounds for revocation was based on not meeting sufficiency of disclosure requirements. The IPAB arrived on a final conclusion that ‘the sufficiency requirement is met if at least one way of working the invention is clearly described enabling a skilled person to carry out the invention.’ It was further stated by the IPAB that for the purposes of Section 10(4), ‘it is not necessary for a patent specification to enable the skilled artisan to carry out all conceivable ways of operating the invention. If the best method known to the applicant is disclosed in the specification, it satisfies the requirement of sufficiency of disclosure.’

In another case of Indian Patent No. 184038, the IPAB acknowledged that the patent specification meets the requirement of sufficiency of disclosure, wherein the complete specification disclosed only one working example, but that particular example was the best method of working the invention known to the Applicant at the time of filing which encompassed the full breadth of the technicalities associated with the claimed invention in said patent application.

Further, in a pre-grant opposition (filed by Cipla Ltd.) in the patent application no. 396/DEL/1996, having Gilead Science Inc. as the Applicant, it was held by the Controller of Patents that: “In order to satisfy the requirement of sufficiency of description, the applicant for patent is under public duty to satisfy at least following three conditions, namely:

  1. The complete specification must describe an embodiment of the invention claimed in each of the claims,
  2. The description must be sufficient to enable those in the industry concerned to carry it into effect without making further invention or experiments and
  3. The description must be fair, i.e., it must not be unnecessarily difficult to follow.

Furthermore, in the matter of a post-grant opposition filed in respect of Patent no. 198079 granted to A.R. Safiullah, an order for revocation was passed by the Ld. Controller wherein one of the grounds for revocation was insufficient disclosure under Section 25 (2) (g) of the Patents Act, 1970. The detailed description lacked clarity with regard to the features of the claimed invention and also about its various components and their functions that was observed to be insufficient for a person skilled in the art to carry out the invention. The controller held that: “The basic essence of patenting is to give full and complete disclosure to public so that the invention can be carried out based on the teachings of the specification and thereby give monopoly, right in exchange of these.”

Since the complete specification is a techno-legal document and being an extremely important document as the disclosure made in this document would define the subsequent stages following the filing of the patent application. Thus, it becomes extremely important that drafting of a complete specification meets all the requirements of Section 10 (4) of the Act.

Therefore, to ensure that during an examination of the application and at subsequent stages the application is not refused on the basis of not meeting sufficiency of disclosure the applicant must ensure that the specification is well-drafted disclosing the complete scope of the claimed invention and provides at least one working example sufficient enough to enable a person skilled in the art to make and use the invention without exercising inventive skill.

[1] AIR 1983 Bom

[2] 1969 Bom 255


[4] For ref. on page 38, paragraph 11.5 of

[5] For ref. page 39, paragraph 11 of

[6] Order no. 166 of 2012

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