315 jobs will be affected by the closure, which is set for March 2026.
The Taoiseach says he'll be prioritising finding an alternative investor as an Offaly manufacturing plant is set to close.
Cardinal Health announced plans to consolidate its Tullamore operations to other facilities by March 2026, impacting 315 jobs at the site.
A wind-down of operations is to begin next April, while SIPTU has begun a 30-day consultation period with the company.
Taoiseach, Simon Harris, says it's very bad news for the town:
Staff were informed of the decision at a meeting yesterday morning, after the company shut down operations on Wednesday afternoon.
It's understood the closure will see one of the company's product lines discontinued and the remaining two relocated to Mexico and Costa Rica.
The plant was first operated by Sherwood Medical in 1982, but has changed hands numerous times over the years.
The Enterprise Minister says he's confident the closure of an Offaly manufacturing plant will be an isolated incident.
Minister and Longford Westmeath TD, Peter Burke, says the Live Sciences sector remains strong in the midlands:
Read more: 'Desperate Times For The Area' - Tullamore Chamber Responds To Loss Of 300 Jobs