Miners has made seminal contributions to the characterisation of the enzymatic basis of drug metabolism, which underlies the individualisation of drug therapy in humans. His research has interwoven molecular, biochemical and clinical approaches to identify sources of variability in drug metabolism, characterise the substrate and inhibitor selectivities and structure-function relationships of the key drug metabolizing enzymes cytochrome P450 and UDP-glucuronosyltransferase, and develop in vitro experimental paradigms that predict drug metabolism parameters in humans. The research has played a pivotal role in establishing drug metabolism as a predictive science that underpins both preclinical drug development and the clinical use of drugs.