IDMA had in July this year challenged the amendments, even as the Government had in its affidavit said that the changes were necessary for compliance under TRIPS.

The division bench comprising justice Ghodeshwar and justice Radhakrishnan on Thursday asked all parties concerned to file written submissions by September 27. Earlier, the division bench had admitted an intervention application from the Institute of Intellectual Property in support of the Government, while the Intellectual Property Law Practitioners' Association has now sought to support most points raised in the IDMA petition.

The law practioners' body has expressed concern over certain procedural issues (like doing away with an endorsement from the true and first inventor in a patentapplication, reduced disclosure requirements arising out of fewer number of forms) and the proviso which seeks to grant an automatic stay when a patentee seeks a review on a compulsory licence issued.

The IDMA had earlier filed its rejoinder to the Government affidavit in the case. The rejoinder, broadly speaking, attempts to highlight the alleged lacunae in the patent rules, even while suggesting that safeguards like the compulsory licensing provision have been watered down.

The manufacturers' association had originally moved court challenging various allegedly "objectionable" clauses laid down in the rules. The drug body had claimed that the amended rules go much beyond TRIPS requirements and even supersede the basic Patents (Amendment) Act, 1999.

The association had also claimed that since the patent rules are meant to carry out the provisos in the Patents Act, there is no justification, at this stage, to make drastic changes that supersede the basic act. Moreover, experts view this as a wastefulexercise given that the Patents Act 1970 is due for major changes for compliance under TRIPS before 2000.

Patent experts say that the rules, among other things, dilute the powers of the Government to intervene and sell/distribute a patented invention in "public interest" and virtually limit the period of use of compulsory licences.