Section 3(d) Compliance Screening
India-specific "known substance" derivative classification.
Imatinib mesylate, beta-crystalline form vs. Imatinib (free base): SALT under Section 3(d)
Same active molecule; new compound adds counterion fragment(s): ['CS(=O)(=O)O']. Falls under Section 3(d)'s 'salts' category. Real case: Novartis AG v. Union of India, Supreme Court of India, 2013 (the landmark Section 3(d) ruling -- bioavailability improvements alone, without proven enhanced therapeutic efficacy, do not meet the 3(d) bar).
Erlotinib hydrochloride, Polymorph B specifically vs. Erlotinib hydrochloride (as claimed in IN196774, Polymorphs A+B): IDENTICAL_STRUCTURE under Section 3(d)
Structures (including any salt form) are identical at the SMILES level. If these are being presented in the patent as distinct, the difference is almost certainly a POLYMORPH, PARTICLE SIZE, or other solid-state/crystal-form difference -- this cannot be determined from structure alone (no XRPD/DSC/crystal data available here). Section 3(d)'s 'polymorphs'/'particle size' categories presumptively apply; flag for manual crystallographic review. Real case: F. Hoffmann-La Roche Ltd v. Cipla Ltd, Delhi HC Division Bench, RFA(OS) 92/2012 & 103/2012, 2015 -- the separate Polymorph-B-specific application was rejected 2008-12 on Section 3(d) grounds after Cipla's opposition.
Formula (5a): the methyl ester analog (PubChem CID 86711696) vs. 2-[(2-hydroxy-4,5-dimethoxybenzoyl)amino]-1,3-thiazole-4-carboxylic acid ethyl ester (prior art D1/D2, PubChem CID 15508009, 'Acotiamide Impurity J'): POSSIBLE_ESTER_ETHER_DERIVATIVE under Section 3(d)
Molecular weights are close (known=352.1, new=338.1) but structures differ beyond simple salt/isomer relationship -- consistent with an ester/ether/other simple derivative under Section 3(d), but NOT confirmed by substructure matching here. Flag for manual confirmation, do not treat as certain. Real case: Zeria Pharmaceutical Co. Ltd v. Deputy Controller of Patents, Delhi HC, C.A.(COMM.IPD-PAT) 452/2022, judgment 2025-05-27 -- ethoxy-to-methoxy ester swap held an obvious modification, refusal affirmed for lack of proven efficacy.
Need this run on your own compound or patent? Section 3(d) Screening needs a hand-reviewed case build, not an automated minutes-long check — get a Standard Report with real human sign-off.
Frequently asked
What is Section 3(d) screening?
An India-specific check of whether a claimed compound is a salt, ester, isomer, or other "known substance" derivative of something already known — the structural half of the test used to strike down Novartis's Glivec patent.
Does it decide if a patent is invalid?
No — it flags the structural relationship for your review. Whether therapeutic efficacy was actually enhanced is a separate clinical/legal question outside its scope.
What's the turnaround?
Human-reviewed Standard Report, not an automated instant check — real sample output is on this page so you can see the format first.