Home Drug Testing Kit: The Stability of Drugs and Metabolites in Urine During Incubation at 37 °C

Abstract

The stability of drugs and metabolites in urine was investigated for the development of a D.O.A. (Drugs of Abuse) home testing kit. The objectives were to maintain the drug levels in the urine specimens at least 4-7 days through the mailing process and throughout a broad range of temperatures, to find the best sample container for shipment and storage purposes, and to determine if preservative tablets will be needed to stabilize the drugs in the urine. Drug positive urine samples were incubated at 37°C for four weeks and tested on different days for ethanol, amphetamines, cocaine, cannabinoids, PCP, and opiates using the Abbott TDx instrument system to run the clinical assays. Four different sample container and two different kinds of preservative tablets were evaluated to detect if one maintained the stability of the drug levels in the urine better than another. Completion of the studies indicated that all the drugs, except cocaine and PCP, showed stability of at least 7 days with or without preservatives at 37°C. To prevent cocaine metabolites, cannabinoids, and ethanol levels from declining over time, 420 mg of Boric Acid (Cult-ur) tablets was needed to keep these drug levels stable. There was no differences between the four sample containers evaluated throughout the study. The Corning/Samco bottles were chosen to be used in the drug home-testing kit because these bottles were easiest to handle.