Dean S. Hsieh, the founder of Conrex Pharmaceuticals Corporation, began his life with a humble foundation. Growing up in a one-room mud cabin in Taiwan, his drive for academic excellence and hard work awarded him a spot at the top university in Taiwan, National University of Taiwan. Pursuing his academic endeavors, he immigrated to the United States of America to further his education. Studying at MIT and earning his Phd, he completed his postdoctoral work as a biomaterials scientist at Harvard University.


As an assistant professor, Dr. Hsieh taught as an assistant professor of Pharmacy at Rutgers University in New Jersey where he edited a two-volume study, “Controlled Release Systems” and previously edited “Drug Permeation Enhancement Theory and Applications.” Recognized as an expert in drug delivery technology, Dr. Hsieh published over 70 scientific articles and was the organizer and moderator of the drug delivery panel at the PharmTech Conference.



With an understanding of the field of alternative drug delivery technology and through his role in the study, Dr. Hsieh was able to analyze and determine market niches. After great research and discovery, he patented an FDA approved novel delivery system, Permeation Enhancement Technology™ or P.E.T.™.


P.E.T.™ is an effective well-tolerated, transdermal delivery system. It is the FDA (US Food and Drug Administration) approved delivery system incorporated in the product Testim™ (Auxilium Pharmaceuticals). P.E.T.™ enables the temporary transport of drug molecules and hormones into and through the skin (transdermal) as an alternative to delivery by mouth or injection.


It is extremely versatile and compatible with most formulation components permitting use in cosmetics and hair treatments as well as pharmaceuticals. P.E.T.™ currently holds two US patents, one for pharmaceutical applications, which is licensed to Bentley Pharmaceutical Corporation (Bentley’s trademarked name for P.E.T.™ is CPE-215™), and a second owned by Conrex Pharmaceuticals Corporation for hair and skin treatments (Patent No. 5,731,303.)



Dr. Hsieh married Phyllis Wang, in 1982 and together they built a family and a business dream founded on science. Dr. Hsieh dedicated his research at Conrex to the study of permeation enhancement technology in hopes of finding a drug delivery method with the potential to give people access to a wider range of drugs with a higher safety factor than conventional delivery methods. Working side by side, their family grew with the birth of their daughter Esther. Soon after they welcomed a son, Matthew, and once again another son, Joseph.


Unfortunately, their beloved husband and father was diagnosed with ALS (Lou Gehrig’s disease) and passed away in 1995. His courage and dedication to hard work and family remains the foundation of the family’s business today.


Upon Dr. Hsieh’s passing, his wife, Phyllis, continues today as the family’s matriarch and as the President of Conrex Pharmaceuticals Corporation and its sister company, which she created, Sesha Skin Therapy.


Using P.E.T.™, Phyllis, and her second husband, Tom Liu, a cosmetic chemist, began to formulate skincare products to nourish the skin. Liu has been instrumental in formulating the Sesha Skin Therapy professional product range. Utilizing performance ingredients and high-quality botanicals in optimum levels of formulation, Liu has developed a clinical treatment skincare range meeting every need and goal based on the belief that nourishing the skin is the foundation to healthy-looking skin.



As a local company, Sesha Skin Therapy is pleased to have an in-house research facility, and cosmetic formulators dedicated to the latest developments in research and discovery. Nearly twenty years after Sesha Skin Therapy was established as a medical and professional skin care product range, Hsieh’s original vision remains intact through the perseverance and dedication of the family matriarch, Phyllis.


Sesha Skin Therapy is headquartered in West Chester, Pennsylvania, USA. The cosmetic chemistry labs and manufacturing facility are both located on the same campus allowing the cosmetic chemistry team to oversee the production of each and every product from conception to final formulation and fulfillment. The company remains at the forefront of cutting edge skin care technology and in the backbar of estheticians across the world.


Phyllis and her daughter, Esther Tou, VP of Marketing, have now joined together to continue building the successful Sesha Skin Therapy product range honoring science, technology and family. This Mother’s Day we celebrate the mother and daughter duo leading the company into the future as they honor the legacy of their late founder, Dean Hsieh.