Metabolite profiling and identification service
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Understand the drug metabolism of your compound by identifying which metabolites are formed during in vitro or in vivo studies.
Metabolite profiling and identification is one of our Cloe Select portfolio of experimental ADME services. Cyprotex deliver consistent, high quality data with the flexibility to adapt protocols based on specific customer requirements.
Profiling and identification of metabolites
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Understanding which metabolites are likely to be formed in vivo is essential for interpreting pharmacology, pharmacokinetic and toxicology data.
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Cyprotex use the Applied Biosystems Sciex QTRAP® 5500 LC-MS/MS for these studies, one of the most sensitive ion traps in the industry.
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Cloe Select Metabolite Profiling and Identification service provides critical information on the formation of metabolites including, where appropriate, both Phase I and Phase II metabolism, and comparison of drug metabolism routes in different species.
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Metabolites can be investigated in a number of different matrices including microsomal incubations, hepatocyte incubations, expressed enzyme incubations or plasma samples.
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Cyprotex offers a range of metabolite profiling services depending upon the level of detail and interpretation required.
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‘We encourage the identification of differences in drug metabolism between animals used in nonclinical safety assessments and humans as early as possible during the drug development process. The discovery of disproportionate drug metabolites late in drug development can potentially cause development and marketing delays’. |
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FDA Guidance for Industry: Safety Testing of Drug Metabolites (February 2008) |
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Service options available for metabolite profiling and identification
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Service Option |
Deliverables |
Suitable for |
LC-MS
Metabolite Profiling |
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Ion chromatogram of parent and proposed metabolites.
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Name of proposed metabolites and where possible molecular formulae.
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Table containing metabolite masses,
absolute areas, retention time and mass difference from parent.
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Profile of metabolites formed by Phase I or Phase II metabolism.
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Cross species metabolite profiling.
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LC-MS/MS
Metabolite Profiling |
As above +
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MS/MS spectra of parent and proposed metabolites.
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Details of the product ion fragments of parent and any potential metabolites.
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Confirmation of metabolites identified
by LC-MS scan.
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Detailed metabolite characterisation
including structural derivation.
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Interpretation and
Structural Derivation |
As above +
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Structural interpretation of the data based on the key fragments observed.
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Detailed report containing proposed
metabolite structures and expected metabolic pathways.
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Expert consultation.
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Data from the Cloe Select Metabolite Profiling and Identification service
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Comparison between the AB Sciex QTRAP® 5500 and the Waters Quattro Micro™ for dextromethorphan metabolism in human liver microsomes. |
The AB Sciex QTRAP® 5500 LC-MS/MS detects two additional minor metabolites which were not detected using the Waters Quattro MicroTM LC-MS/MS as shown in the chromatograms below.
Detailed MS chromatogram and spectra are provided for metabolites:
 In addition, MS/MS spectra can also be provided along with a detailed report which provides interpretation of the data:
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Questions and answers on metabolite profiling and identification
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Why is understanding the routes of metabolism of a compound important?
There are several reasons why understanding the metabolic profile of a compound is important. Firstly, the FDA Guidance for Safety Testing of Drug Metabolites (2008) recommends in vitro evaluation of interspecies differences in drug metabolism between humans and those animals which are expected to be used in preclinical safety assessments. If a metabolite is formed only in humans and is absent in the animal test species, or if the metabolite is present at disproportionately higher levels in humans than in the animal species, then it may be necessary to assess the preclinical safety of the metabolite in question. Secondly, understanding the metabolic liability of a compound is important in directing chemistry. If a compound is very rapidly cleared, then identifying which functional groups are undergoing metabolism will be valuable in understanding how the chemistry may be altered to reduce compound degradation.
What do you recommend as an appropriate strategy for evaluation of the routes of metabolism of a compound?
Before embarking on an in vitro metabolite profiling study, it is recommended that the compound has previously been investigated in the in vitro drug metabolising system of choice. This will give an indication of the extent of metabolism and whether sensitivity on the LC-MS is likely to be a problem.
For in vivo metabolite profiling studies, we generally recommend pooling samples to obtain the best LC-MS response. In these studies polymer solvents in dosing solutions (i.e. PEG) are best avoided due to the possible interference by ion suppression in plasma samples.
The decision on which service to choose is very much dependent on the level of interpretation required. Our standard Cloe Select service uses a simple LC-MS scan to determine the mass and abundance (relative to parent) of any metabolites found. This can be extended to a more in-depth service using LC-MS/MS to obtain fragmentation details on any potential metabolites. Cyprotex are able to offer a specialist interpretation service on this information, proposing potential metabolite structures and possible metabolite pathways.
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Cloe® is a registered trade mark owned by Cyprotex PLC
