Once the process patent is granted, the respondent is estopped from rejecting the product patent for lack of inventive step: Madras High Court

In a significant judgment, the High Court of Judicature at Madras has overturned the rejection of Kyorin Pharmaceutical Co., Limited’s patent application for an orally, rapidly disintegrating tablet with excellent photostability. The court ruled that the rejection by the Assistant Controller of Patents and Designs was erroneous, particularly in light of an already granted process patent for the manufacturing method. The decision underscores the importance of distinguishing between product and process patents under Indian patent law.

Kyorin Pharmaceutical Co., Limited, formerly known as Kyorin Holdings Inc., Japan, filed a patent application (No. 5360/CHENP/2010) for an innovative orally, rapidly disintegrating tablet. This tablet is designed to be photostable, making it easier to administer to children and the elderly. However, the Assistant Controller of Patents and Designs rejected the application on grounds of lack of inventive step under Section 2(1)(ja) and non-patentability under Section 3€ of the Indian Patents Act, 1970.

The High Court noted that the rejection was based on prior arts D1, D3, and D5, which were deemed to teach away from the claimed invention. Justice Balaji highlighted that the European Patent Office had granted a patent to Kyorin Pharmaceutical considering the same prior arts. Additionally, the process patent for manufacturing the tablet had already been granted to the appellant in a co-pending application, reinforcing the inventive step.

“Once the process patent for the method of manufacturing the tablet is granted, the respondent is estopped from rejecting the product patent for lack of inventive step,” the judgment emphasized.

Distinction Between Product and Process Patents:

The court underscored the legal distinction between product and process patents. It clarified that a granted process patent does not negate the inventive step in the product itself. Justice Balaji criticized the respondent’s approach of conflating the two and reopening scrutiny of the process after granting the process patent.

“Product patents and process patents are different, and merely because the appellant successfully obtained a patent for the process, the application for a product patent cannot be refused,” the court noted.

While the court set aside the rejection based on lack of inventive step, it remitted the issue of non-patentability under Section 3€ back to the Assistant Controller for fresh consideration. The court mandated that a different Patent Controller should conduct the re-evaluation and include a hearing for the appellant.

Justice Balaji remarked, “The process for which the patent was granted is distinct and different from the resultant product arising from the employment of the process. The respondent was estopped from even examining ‘lack of inventive step’.”

The High Court’s judgment in favor of Kyorin Pharmaceutical marks a pivotal moment in patent law, reinforcing the distinction between product and process patents. By overturning the rejection and remanding the issue of non-patentability for fresh consideration, the court has ensured a fair reassessment of the appellant’s claims. This decision is expected to have significant implications for future patent applications, particularly those involving innovative pharmaceutical products.

Date of Decision: 05.07.2024