Oxythiamine diphosphate is primarily used in biochemical research to study thiamine-dependent enzymes and metabolic pathways. It acts as a competitive inhibitor of thiamine pyrophosphate (TPP), allowing researchers to investigate the role of thiamine in cellular processes. This compound is particularly valuable in understanding metabolic disorders related to thiamine deficiency, such as beriberi and Wernicke-Korsakoff syndrome. Additionally, it is utilized in enzymology to explore the mechanisms of enzymes like transketolase and pyruvate dehydrogenase, providing insights into their function and regulation. Its inhibitory properties also make it a useful tool in drug development for targeting thiamine-dependent pathways in diseases like cancer and diabetes.