Riverside Company-backed Red Nucleus Enterprises has acquired Malvern, Pa.-based Pyxa Solutions, a provider of cross-functional R&D services. Regulatory Affairs. Pyxa's principals retained a significant interest in the combined company. 

Founded in 2012, Pyxa helps life sciences companies obtain regulatory services from industry veterans who "grew up in pharma." Pyxa's team of senior management consultants and topical experts provide services spanning the entire drug development life cycle for developed and emerging markets.

The three key executives of Pyxa Solutions—Carol Rutkowski, Michael Swalina and Dalia El-Sherif—will continue to lead the Pyxa operations.