Essex Woodlands, a $2.5 billion equity investment firm, is taking another $15 million stake in RTP-based Metabolon, which focuses on the growing field of metabolomics.

Essex invested $15 million in Metabolon last year.

“Proceeds from this additional round of financing have been fully utilized by the company to repurchase and retire certain shares held by existing investors,” Metabolon said in a brief statement Monday

In the investment last year, Metabolon had said another $10 million can be used to buy shares of earlier investors, the firms disclosed.

Metabolon defines metabolomics as an integration of “the influences of genes, diet, lifestyle, environment and xenobiotics to help explain gene function and how diseases originate and identify biomarkers for health assessment and customized drug therapy.”

“We believe the potential applications for metabolomics are just beginning to be appreciated, and we are therefore excited to support the continued growth of the leading metabolomics technology platform developed by Metabolon,” said Scott Barry, Managing Director at Essex Woodlands, in the funding announcement last year.

“We are very pleased to partner with [CEO] John [Ryals] and Metabolon’s world-class management team to continue the company’s trajectory of success in exploring the functionality of metabolomics in precision medicine in particular, and Essex Woodlands’ network of relationships in the healthcare industry will support and expand this impressive technology in new applications and partnerships going forward.”

As part of the deal, Barry joined the Metabolon board.

Metabolon, which launched in 2000, has now raised some $95 million in equity investment.