Amulet Capital Partners has sold OPEN Health to Astorg, according to a news release.

OPEN Health, established in 2011 and with several U.S. offices, is a global provider of scientific communications and market access services to the pharmaceutical industry.

Amulet, based in Greenwich, Conn., is a middle market private equity investment firm focused exclusively on the healthcare sector. Founded in 2012, the firm typically invests between $25 million and $150 million in healthcare companies within segments that include life sciences outsourcing, payors and payor services, and providers and outsourced services.

Astorg is a European private equity firm with a U.S. office in New York.

Terms of the transaction were not disclosed.