Closure of trading window for the quarter ended September 30, 2026

Corporate Office: Registered Office: Star 1, Opp IIM Bangalore, Bilekahalli, Cyber One, Unit No. 902, Sector 30A, Bannergha(cid:425)a Road, Bengaluru – Plot No - 4 & 6, Vashi, 560076, India Navi Mumbai - 400703, India T: +91 80 6784 0738 T: +91 22 2789 2924 Date: September 24, 2026 BSE Limited National Stock Exchange of India Limited Phiroze Jeejeebhoy Towers Exchange Plaza, C-1, Block G, Bandra Kurla Complex, Dalal Street, Mumbai- 400001 Bandra (E), Mumbai – 400 051 Scrip Code: 544292 Symbol: ONESOURCE Dear Madam/ Sirs, Subject: Intimation regarding closure of Trading Window Pursuant to the provisions of the Securities and Exchange Board of India (Prohibition of Insider Trading) Regulations, 2015 and Code of Conduct for Prohibition of Insider Trading of OneSource Specialty Pharma Limited (“Company”), for regulating, monitoring and reporting of trading by insiders, we hereby inform you that the Trading Window for dealing in shares of the Company shall remain closed from Thursday, October 01, 2026, until 48 hours after declaration of the financial results of the Company for the quarter ended September 30, 2026. The date of the Board Meeting for declaration of financial results of the Company for the quarter ended September 30, 2026, will be intimated in due course. Kindly take the above information on record. For and on behalf of OneSource Specialty Pharma Limited Trisha A Company Secretary and Compliance Officer Membership Number: A47635 OneSource Specialty Pharma Limited info@onesourcecdmo.com | www.onesourcecdmo.com CIN: L74140MH2007PLC432497