Deuterated Internal Standards for Equine Therapeutic Medication Regulation

Fifty plus therapeutic medications with potential to affect performance are recognized by the American Association ofEquine Practitioners [AAEP] and the Racing Medication and Testing Consortium [RMTC] and approved for use in horses in training. Current analytical testing is highly sensitive; regulators are therefore committed to accurate quantification of defmed residues oftherapeutic medications in post-event samples. This commitment creates a requirement for stable isotope internal standards, as explicitly set forth in "International Laboratory Accreditation Committee (lLAC-G7:0612009 Accreditation Requirements and Operating Criteria for Horseracing Laboratories". However, a number ofrequired stable isotope internal standards are not currently commercially available to racing chemists. Equally important, the unavailable standards tend to be those for which the market is small and or their synthesis is technically challenging. In North America about 500,000 equine drug testing samples are tested. In support of this testing process we will synthesize and make available stable isotope internal standards for selected equine therapeutics, not currently commercially available to racing chemists. More recently, the national and international drive towards standardized testing has created a requirement for significant quantities of hitherto unavailable deuterated internal standards for butorphanol as butorphanol--d6, pyrilamine as pyrilamine-ds, 3-hydroxymepivacaine as 3hydroxymepivacaine-ds and isoflupredone as isoflupredone-ds. To date, our research group has synthesized a number ofreference standards and stable isotope internal standards and provided many ofthese to the racing industry but many standards remain to be created, a significant technical challenge. Since these medications are used in racing and performance horses worldwide, and since the need for regulatory controls on equine therapeutic medications is unlikely to disappear, these circumstances have created an ongoing need for equine therapeutic medication internal standards to address the world-wide need to scientifically and forensically regulate use ofthese equine therapeutic medications.