Impact of Drone Versus Car Transport on Anti-Doping Sample Integrity Over Short Distances: A Proof-Of-Concept Study

This study investigated whether drone transportation resulted in measurable changes in biological variables relevant to the Athlete Biological Passport, including the urinary steroid profile, haematological factors, selected clinical markers and the untargeted metabolome in dried blood spots (DBS). Urine, blood and DBS from healthy volunteers were analysed after car, drone or no transport, over 5 or 20 km. Haematological factors were assayed by a haematology analyser, steroid profile by GC-/LC-MS and metabolomics by UPLC-MS/MS. Drone was faster than car across both distances, and performance was unaffected by high temperatures (29°C-32°C) or wind speed (12-20 km/h). Haematological, urinary steroid and routine clinical chemistry markers showed no significant differences between car and drone at either distance. Metabolomic analysis showed that most metabolites from DBS samples remained stable relative to no transport: 88% at 5 km and 81%-84% at 20 km for both modes. Using a control-anchored equivalence framework, 92.3% of metabolites were classified as equivalent between car and drone at 5 km, and 88.0% at 20 km, with strong correlation across the full metabolome (r = 0.78 at 5 km, p-value < 0.001; r = 0.82 at 20 km, p-value < 0.001). This is the first report to evaluate drone transport across all major anti-doping sample matrices (urine, whole blood and DBS) using both targeted clinical assays and untargeted metabolomics. Steroid profile, haematological and clinical markers, as well as most DBS-derived metabolites, were equivalent following drone delivery compared with car transport, making this mode of sample transport a possible option during major sporting events.