ON-DEMAND WEBINAR:
Evaluation of two β-Glucuronidases for Urine Drug Testing
Dr. Nguyen Nguyen earned his PhD in Chemistry from UC-Davis and his clinical chemistry fellowship from Baylor Scott & White. Dr. Nguyen began his career in biopharmaceutical and transitioned to clinical research at UC-SF. He has setup a number of small clinics and a reference lab. He is currently the clinical chemist/toxicologist and safety officer at the Baylor Scott and White Medical Center. With over 10 years of experience, he’s here to share with you one of his recent works in drug testing.
OBJECTIVES
Liquid chromatography tandem mass spectrometry (LC-MS/MS) has been the gold standard method for urine drug testing (UDT). Analytical sensitivity and specificity of drugs have increased dramatically due to mass spectrometry detection. In addition, the beta-glucuronidase in the sample workup step also helps recover parent drug compounds by hydrolyzing glucuronides on metabolites, which were formed through normal metabolism. There are many types and generations of beta-glucuronidases available, and here, we are evaluating two of the current modern products for their deconjugation performance on commonly prescribed opioids and benzodiazepines at room temperature (20-25°C).
METHODS
Urine remnants of specimens, previously confirmed positive, were pooled together to include many opioids and benzodiazepines of interest. Optimization study was carried out by varying each product amount from 0 to 100uL. The samples were incubated for 15min at room temperature along with deuterated internal standards. A diluent of 43% methanol in water was added prior to MS/MS detection of 12 opioids and 7 benzodiazepines. Results were normalized to the highest amount for graphical evaluation. We define performance adequacy if conjugation achieved of at least 80% of highest normalized value.
RESULTS & CONCLUSION
For benzodiazepines, the recovery was best achieved by using 20uL of our current enzyme or IMCSzyme RT. For opioids, the recovery was best achieved by using 80uL and 20uL of the current enzyme/buffer product and IMCSzyme RT, respectively. Both products offered similar performance in extracting parent opioids and benzodiazepines compounds from urine at room temperature.
β-glucuronidases recover drug compounds by hydrolyzing glucuronides on metabolites formed by normal metabolism. In this talk, Dr. Nguyen Nguyen, Clinical Chemist/Toxicologist and Safety Officer at Baylor Scott & White, presents his group's evaluation of two novel β-glucuronidase products, IMCSzyme RT and "CE" (their "current enzyme"), for recovery of common opioids and benzodiazepines at room temperature.
At the end of this webinar, participants will:
- Learn about the phases of drug metabolism and why β-glucuronidase enzymes is necessary in urine drug testing,
- Recognize the advantages of novel room-temperature β-glucuronidases
- Discuss the possible mechanisms behind the enzyme- and patient-dependent differences in deconjugation performance between the two enzyme products.