Samuel Arnold

Assistant Professor

Department of Pharmaceutics, Pharmaceutics Faculty, School Faculty

Telephone: (206)616-4218


Website: Linkedin

Accepting Students to Lab: Yes


  • Bachelor of Science in Biochemistry, University of Colorado
  • Ph.D. in Pharmaceutics, University of Washington

Research Interests

  • Infectious Diseases, Pharmacokinetic-pharmacodynamic modeling for treatment of enteric infections
  • Enteric disease induced changes in drug disposition
  • Improved preclinical models of drug disposition in the GI

Courses Taught

  • PCEUT531
  • PCEUT532
  • PCEUT506


Dr. Samuel Arnold joined the Department of Pharmaceutics at the University of Washington as an Assistant Professor in 2023, and his research predominantly focuses on characterizing exposure-response relationships for therapeutic treatment of infectious diarrhea. While there has been a substantial reduction in diarrhea associated mortality over the past decade, diarrheal diseases continue to be a major global health concern (second leading cause of death in children < 5 years old). The remarkable reduction in disease burden can be attributed to many factors, and this includes vaccine rollout for rotavirus. However, with a reduction in rotavirus infections, there has been a concurrent increase in the proportion of diarrheal diseases attributed to other etiological agents of disease (e.g., Cryptosporidium and Shigella). Dr. Arnold’s work includes the development of in vitro and in vivo models for cryptosporidiosis and shigellosis. As a member of the Bill & Melinda Gates Foundation Cryptosporidium Drug Accelerator (CryptoDA), Dr. Arnold led a successful effort to identify pharmacokinetic/pharmacodynamic (PK/PD) relationships for anti-cryptosporidiosis drugs. Due to the gastrointestinal localization of the pathogen, this work required a non-traditional experimental approach to identify exposure-response relationships. In addition, Dr. Arnold provided clinical pharmacology support for an anti-cryptosporidiosis clinical trial in Malawi ( #NCT03341767) that investigated clofazimine as a potential anti-cryptosporidiosis treatment. Subsequent analysis of the data from this trial has demonstrated that a participant’s diarrheal status is associated with therapeutic exposure. Based on these results, the Arnold lab is working on the development of pharmacokinetic models that can predict the impact of diarrhea on drug exposure prior to human dosing.

Selected Publications