Development and GC-MS validation of a highly sensitive recombinant G6PDH-based homogeneous immunoassay for the detection of buprenorphine and norbuprenorphine in urine.
Buprenorphine is now increasingly prescribed as an alternative to methadone for the treatment of heroin addiction. Because of its potency (dosage usages from 0.2 mg to 8 mg), the drug concentrations in body fluids are normally very low. Here, we report the first recombinant glucose-6-phosphate dehydrogenase (G6PDH)-based homogeneous immunoassay (EMIT-type assay) for free buprenorphine and free norbuprenorphine in urine. The antibody used in this assay cross-reacts nearly identically with buprenorphine and norbuprenorphine and, at the same time, has less than 1% cross-reactivity with a wide range of commonly prescribed opiates, particularly those structurally related compounds such as morphine, codeine, and dihydrocodeine. More importantly, this assay has a low detection limit of 1 ng/mL for buprenorphine or norbuprenorphine. Further evaluation of this technique using gas chromatography-mass spectrometry (GC-MS) of authentic urine samples demonstrated that the accuracy of the assay is greater than 95%. Because this assay is designed to measure the free drugs in urine, it resulted in simplification for GC-MS or liquid chromatography-MS confirmation methods that did not require urine hydrolysis before solid-phase or liquid-liquid extraction.
Wang
Guohong
G
Immunalysis Corporation, 829 Towne Center Drive, Pomona, California 91767, USA.
Vincent
Michael
M
Rodrigues
Warren
W
Agrawal
Alpana
A
Moore
Christine
C
Barhate
Rekha
R
Abolencia
E
E
Coulter
Cynthia
C
Soares
James
J
Zheng
Yi-Feng
YF
Taylor
Celeste
C
Morjana
Nihmat
N
D000701:Analgesics, Opioid / Q000627:therapeutic use / Q000652:urine*; D002047:Buprenorphine / Q000031:analogs & derivatives* / Q000627:therapeutic use / Q000652:urine*; D003429:Cross Reactions; D017248:Enzyme Multiplied Immunoassay Technique; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D005954:Glucosephosphate Dehydrogenase; D006556:Heroin Dependence / Q000188:drug therapy; D006801:Humans; D011994:Recombinant Proteins; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods
D000701:Analgesics, Opioid; D011994:Recombinant Proteins; D002047:Buprenorphine; C043585:norbuprenorphine; D005954:Glucosephosphate Dehydrogenase