Lek announced the plan last week, explaining it will expand the existing plant on to land adjacent to the site that it acquired from Koratur last year.
The firm did not disclose how much the project will cost or by how much it will increase capacity, but did say several production lines would be introduced over the next few years.
A Sandoz spokesman told us the investment was "based on the high quality of products and processes, expertise of the Prevalje associates, and continuing growth of demand."
The facility produces a version of GlaxoSmithKline's Augmentin, a broad spectrum antibiotic that consists of amoxicillin and clavulanic acid.
According to the Sandoz spokseman "products from this site are treating patients in approximately 60 markets, the majority of the sales are made through our own marketing and sales network."
Lek currently employs 246 people out the site, although it expects to hire more staff when the expansion is completed in 2023.
The spokesman told us "the investment will create new jobs. The number will depend on the development of this investment. The target is that 25% of these new jobs are employees with high education."
Sandoz’s owner – Swiss drug manufacturer Novartis – has invested €30m ($27m) at the site over the past decade.