Current opinion in drug discovery & development, 2001
The evolution of high-throughput drug discovery is readily apparent as the pharmaceutical industr... more The evolution of high-throughput drug discovery is readily apparent as the pharmaceutical industry continues to stress the rapid progression of new chemical entities and biological agents through drug discovery and development pipelines. Mass spectrometry and high performance liquid chromatography-mass spectrometry have played an instrumental role in the support and advancement of all facets of high-throughput drug discovery. The introduction of new instrumentation has extended the breadth of mass spectrometric-based capabilities from the characterization of high-throughput organic synthesis products to early adsorption, distribution, metabolism and excretion profiling. Additionally, advances in the capacity and throughput of mass spectrometry systems have concurrently led to the introduction of data management tools to address automated data reduction, archival and mining, as well as analytical data integration to chemical and biological databases.
Packed capillary liquid chromatography/mass spectrometry (LC/MS) using electrospray ionization (E... more Packed capillary liquid chromatography/mass spectrometry (LC/MS) using electrospray ionization (ESI) was used to study the human biotransformation of the anti-emetic drug dolasetron. Urine from subjects given a single 100 mg intravenous dose, containing 14C-labeled dolasetron (50 microCi), was de-salted and concentrated for LC/MS with minimal loss of radioactivity (97% recovery). Aliquots of the de-salted material were injected directly onto a C8 packed capillary column (25 cm x 0.32 mm i.d.) and eluted with an acetonitrile-water gradient, buffered with 1% acetic acid, at a flow rate of 2 microliters min-1. Five metabolites were detected by LC ESI-MS which, yielded molecular mass information but no fragmentation. The identity of each metabolite was confirmed in a subsequent analysis using product ion scans in conjunction with collisionally induced dissociation. Precursor ion scanning was also employed and did not reveal any new biotransformation products. In addition to defining the major routes of biotransformation, the data obtained were compared with a 14C radioprofile prepared in a separate experiment. Qualitative agreement in the two chromatographic profiles enabled the major clusters of radioactivity to be assigned to specific metabolites of dolasetron. An important observation in this comparison was that the signal obtained by ESI did not provide an accurate assessment of the quantity of each metabolite. This was especially true for acidic conjugates (i.e. glucuronides, sulfates), which in the case of dolasetron can exist as zwitterions (no net charge). The results demonstrate the power of packed capillary LC ESI-MS for use in drug biotransformation studies and suggest that caution should be exercised when interpreting relative metabolite abundances from ESI data in the absence of actual reference standards.
Page 1. DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY, 20( 19), 3023-3032 (1994) INVESTIGATION INTO TH... more Page 1. DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY, 20( 19), 3023-3032 (1994) INVESTIGATION INTO THE YELLOWING ON AGING OF SABRIL@ TABLET CORES Ron C. George, Robert J. Barbuch, Edward W. Huber, and Brian T. Regg Marion Merrell Dow Inc. ...
Current opinion in drug discovery & development, 2001
The evolution of high-throughput drug discovery is readily apparent as the pharmaceutical industr... more The evolution of high-throughput drug discovery is readily apparent as the pharmaceutical industry continues to stress the rapid progression of new chemical entities and biological agents through drug discovery and development pipelines. Mass spectrometry and high performance liquid chromatography-mass spectrometry have played an instrumental role in the support and advancement of all facets of high-throughput drug discovery. The introduction of new instrumentation has extended the breadth of mass spectrometric-based capabilities from the characterization of high-throughput organic synthesis products to early adsorption, distribution, metabolism and excretion profiling. Additionally, advances in the capacity and throughput of mass spectrometry systems have concurrently led to the introduction of data management tools to address automated data reduction, archival and mining, as well as analytical data integration to chemical and biological databases.
Packed capillary liquid chromatography/mass spectrometry (LC/MS) using electrospray ionization (E... more Packed capillary liquid chromatography/mass spectrometry (LC/MS) using electrospray ionization (ESI) was used to study the human biotransformation of the anti-emetic drug dolasetron. Urine from subjects given a single 100 mg intravenous dose, containing 14C-labeled dolasetron (50 microCi), was de-salted and concentrated for LC/MS with minimal loss of radioactivity (97% recovery). Aliquots of the de-salted material were injected directly onto a C8 packed capillary column (25 cm x 0.32 mm i.d.) and eluted with an acetonitrile-water gradient, buffered with 1% acetic acid, at a flow rate of 2 microliters min-1. Five metabolites were detected by LC ESI-MS which, yielded molecular mass information but no fragmentation. The identity of each metabolite was confirmed in a subsequent analysis using product ion scans in conjunction with collisionally induced dissociation. Precursor ion scanning was also employed and did not reveal any new biotransformation products. In addition to defining the major routes of biotransformation, the data obtained were compared with a 14C radioprofile prepared in a separate experiment. Qualitative agreement in the two chromatographic profiles enabled the major clusters of radioactivity to be assigned to specific metabolites of dolasetron. An important observation in this comparison was that the signal obtained by ESI did not provide an accurate assessment of the quantity of each metabolite. This was especially true for acidic conjugates (i.e. glucuronides, sulfates), which in the case of dolasetron can exist as zwitterions (no net charge). The results demonstrate the power of packed capillary LC ESI-MS for use in drug biotransformation studies and suggest that caution should be exercised when interpreting relative metabolite abundances from ESI data in the absence of actual reference standards.
Page 1. DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY, 20( 19), 3023-3032 (1994) INVESTIGATION INTO TH... more Page 1. DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY, 20( 19), 3023-3032 (1994) INVESTIGATION INTO THE YELLOWING ON AGING OF SABRIL@ TABLET CORES Ron C. George, Robert J. Barbuch, Edward W. Huber, and Brian T. Regg Marion Merrell Dow Inc. ...
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