Mariann T. MacDonald co-founded Endo Pharmaceuticals Inc., a fully integrated independent pharmaceutical company based in Chadds Ford, Pennsylvania with a former co-worker in 1997 following a management buy-out from DuPont Merck Pharmaceuticals. Under their leadership, Endo has become a leader in the growing field of pain management. Revenues grew four-fold from $108 million in 1998 to $400 million in 2002 and to $800 million in 2005 when MacDonald retired. Today revenues are about $3 billion, and the company has a market value of close to $13 billion.

MacDonald retired on December 31, 2005 as Founder / Executive Vice President, Operations, of Endo Pharmaceuticals Inc. MacDonald and her husband Bob moved to Naples, FL. in 2005 and has one child Megan who is married and has a seven year-old daughter named Madelyn.

Prior to co-founding Endo Pharmaceuticals Inc. in 1997, MacDonald served in positions of increasing responsibility for DuPont Pharmaceuticals for 30 years. She joined DuPont Pharmaceuticals in 1968 as an assistant scientist in toxicology and pharmacology. While at DuPont Pharmaceuticals MacDonald held many positions ranging from Director of Operations, Purchasing and Finance to Director of Worldwide Distribution to Senior Director of Integrated Business Systems.

In 1995, MacDonald served as Vice President of Operations for Endo Laboratories, L.L.C., the generic business unit of DuPont Merck at that time. In 1996, she was named Vice President of Business Information, Training, Administration and Technology for the U. S. Pharmaceuticals Division of DuPont Merck. As Vice President, MacDonald was responsible for all field sales administration, sales information, training, technology, and administration for the U.S. division. Her duties entailed managing a budget of more than $10 million and a staff of 140 professionals.

Throughout her career, MacDonald has received several corporate awards, including the DuPont Merck Executive Vice President's Award, the Business Excellence Award and the Summit Award, the highest level of achievement at DuPont Merck. In 2003, she received the Greater Philadelphia Ernst & Young Entrepreneur of The Year Award in the Health Sciences category. MacDonald served as a board member of the Susan G. Komen Breast Cancer Foundation in Philadelphia from 2003 -2005 and has served as the President of the Southwest Florida Affiliate Board of Directors of the Susan G. Komen for the Cure from 2010- 2013. In May of 2009, MacDonald was named to the Board of Trustees of the NCH Healthcare System, in Naples, Florida. In March of 2012, MacDonald was named as the Chairman of the Board for the NCH Healthcare System. In February of 2011, MacDonald was named to the Board of Trustees of the University of Pennsylvania School of Medicine and the University of Pennsylvania Health System. In 2014, the Community Foundation of Collier County named MacDonald as one of the Women of Initiative. In 2014 she was name as one of the Men and Women of the Year by Gulfshore Life Magazine. In 2015, the Florida Hospital Association named MacDonald, Trustee of the Year.

Competencies
·       Management
·       Leadership
·       Business development
·       Operations
·       Finance
·       Budget management