A divisional patent application can be filed unilaterally by the applicant, provided it relates to more than one invention, and the Controller must assess this requirement.

JUDGMENT :

1. This appeal is directed against the order dated 21.05.2024 rejecting Patent Application No.8266/CHENP/2014 for grant of patent for an invention titled 'A Delayed Release Drug Formulation'. The parent Patent Application No.5924/CHENP/2008 was titled 'Colonic Drug Delivery Formulation'. Patent was granted in respect thereof under Patent No.531129 on 30.03.2024. The granted claims therein comprised independent claims 1 and 23, which are as under:

'1. A delayed release drug formulation comprising a particle with a core and a coating for the core, the core comprising a drug and the coating comprising a mixture of a first material which is susceptible to attack by colonic bacteria and a second material which is a film-forming polymeric material having a pH threshold at pH 6.5 or above, wherein the first material comprises a polysaccharide selected from the group consisting of amylopectin, and starch comprising 0.1 wt % to 75 wt % amylose and wherein a ratio of the first material to the second material in the mixture is from 15:85 to 50:50.'

'23. A method of preparing a delayed release drug formulation as claimed in claim 1, said method comprising:

forming a core comprising a drug; and coating the core with a polymer coating preparation comprising a mixture of a first material which is susceptible to attack by colonic bacteria and a second material which has a pH threshold at pH 6.5 or above, wherein the first material comprises a polysaccharide selected from the group consisting of amylopectin; and starch comprising 0.1 wt % to 75 wt % amylose; wherein a ratio of the first material to the second material in the mixture is from 15:85 to less than 50:50.'

2. On the basis that the complete specification relating to the parent application relates to more than one invention, inasmuch as coating in the parent application was in the form of polysaccharide selected from the group consisting of amylopectin and starch, whereas the divisional application pertains to coating comprising polysaccharide selected from the group of chitosan; chondroitin sulfate; cyclodextrin; dextran and carrageenan, the appellant lodged the divisional application. Upon request, the First Examination Report (the FER) was issued on 28.02.2018. In such report, objections were raised inter-alia on the ground of lack of inventive step. The appellant replied thereto on 22.11.2018. Pursuant to hearings on 04.09.2020 and 29.09.2023, the order impugned herein was issued.

3. By referring to the impugned order, learned senior counsel for the appellant submitted that the first respondent misinterpreted Section 16(1) of The Patents Act, 1970 ('Patents Act') as requiring an objection by the Controller on the ground that claims of the complete specification of the parent application relate to more than one invention. By referring to the expression ''if he so desires'' in sub- section (1) of Section 16, learned senior counsel contended that the appellant has the choice to file a divisional application unilaterally even in the absence of an objection by the Controller. The second contention of learned senior counsel is that the monopoly claim granted pursuant to the parent application is confined to coating of polysaccharide selected from the group consisting of amylopectin and starch. Consequently, he submits that the claims submitted along with the divisional application are different in scope and that the grant of divisional application would not result in double patenting. He further submits that the priority date is from 2006. Therefore, it cannot be said that the appellant is endeavouring to evergreen the patent. The third contention of learned senior counsel is that sufficient material was placed on record with regard to the gastro resistant effect of the polysaccharide forming the subject of the divisional application. By referring to the graph in the written submissions of the appellant, he contends that data was provided in respect of each polysaccharide. For all