Arlyn practiced pharmacy for a community chain in Austin from 1962 until 1980 at which time he joined the UT College of Pharmacy as Coordinator of Continuing Education. He has served the college as Director of Professional Affairs and Assistant Dean until 1995 at which time he semi-retired. Currently, he is a Distinguished Lecturer in the College, and coordinates the Care And Respect for the Elderly (CARE) Program.
During his professional career he has served as:
- President of the Texas State Board of Pharmacy
- President of the Capitol Area Pharmaceutical Association
- President of the UT College of Pharmacy Alumni Association
Among the awards received by Arlyn are:
- 2011 Distinguished Graduate Award – Sacred Heart Catholic School, Hallettsville, Texas, awarded by the National Catholic Education Association
- 2011 Distinguished Service Award by the Texas Society of Health-System Pharmacists
- Regents’ Outstanding Teaching Award – 2010 – The University of Texas System Board of Regents
- The Texas Excellence in Teaching Award for Academic Advising from The University of Texas at Austin
- The University of Texas College of Pharmacy William J. Sheffield Outstanding Alumnus Award.
- The 1995 Distinguished Service Award presented by the Texas Pharmacy Association
- The 1998 Gloria Niemeyer Franke Leadership Mentor Award presented by the American Pharmacists Association
- 2005 Individual Educational Excellence Award – Texas Pharmacy Foundation
- 2006 Texas Exes Teaching Award (TETA) for faculty in the College of Pharmacy
In 1995 the title of one of the College of Pharmacy’s awards, the Preceptor of the Year Award, was changed to the Wm. Arlyn Kloesel, Preceptor of the Year Award.
Also, in 1995, friends and colleagues of Arlyn and his wife Mary Carol raised more than $50,000 to establish the Arlyn and Mary Carol Kloesel Endowed Presidential Scholarship.