TDM Pharmaceutical Research LLC

Newark, DE, United States

TDM Pharmaceutical Research LLC

Newark, DE, United States
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Zha W.,TDM Pharmaceutical Research LLC | Shum L.,TDM Pharmaceutical Research LLC
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012

A selective and sensitive high performance liquid chromatography-tandem mass spectrometric method was developed for the analysis of azelastine and its major metabolite, desmethylazelastine, in human plasma. Azelastine-13C, d3 was used as internal standard. Azelastine, desmethylazelastine and the internal standard were extracted by a liquid-liquid extraction method and separation was performed under isocratic chromatographic condition. An abnormal signal loss issue for desmethylazelastine during method development was investigated and resolved. The developed method was precise and reproducible as shown by good intraday assay and interday assay precision (CV%≤12.8%). The calibration curve was linear over a range of 10.0/10.0-1000/200pg/mL for azelastine/desmethylazelastine. The method was successfully applied to a pilot bioequivalence study subsequently. © 2012 Elsevier B.V.


Zha W.,TDM Pharmaceutical Research LLC | Shum L.,TDM Pharmaceutical Research LLC
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012

A selective high performance liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the simultaneous determination of oxymorphone and its active metabolite 6-OH-oxymorphone in human plasma was developed and validated using oxymorphone-d 3 as the internal standard. Chromatographic conditions were optimized to separate oxymorphone from the other metabolite, oxymorphone-3-glucuronide, which may convert to oxymorphone in MS ion source, resulting in inaccurate quantitation of oxymorphone. Solid phase extraction (SPE) was used to extract oxymorphone and 6-OH-oxymorphone from plasma. SPE offered the advantage of being able to remove the unwanted metabolite, oxymorphone-3-glucuronide, through the wash step during the extraction. The developed method was precise and reproducible as shown by good linearity of calibration curves (correlation coefficients ≥0.9968 for oxymorphone and ≥0.9967 for 6-OH-oxymorphone) with high intraday assay and interday assay precision (CV% ≤11.0% for oxymorphone and ≤12.6% for 6-OH-oxymorphone) over a range of 35/25 - 5000/5000pg/mL for oxymorphone/6-OH-oxymorphone. The method has been successfully applied to analyze oxymorphone and 6-OH-oxymorphone in plasma from 19 healthy volunteers in a bioequivalence study. A total of 1026 samples were analyzed. Good linearity (average correlation coefficient 0.9988 for oxymorphone and 0.9966 for 6-OH-oxymorphone) was achieved with calibration curves and high precision (CV% ≤5.9% for oxymorphone and ≤10.9% for 6-OH-oxymorphone) was obtained with QCs. © 2012 Elsevier B.V..


PubMed | TDM Pharmaceutical Research LLC
Type: | Journal: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences | Year: 2012

A selective and sensitive high performance liquid chromatography-tandem mass spectrometric method was developed for the analysis of azelastine and its major metabolite, desmethylazelastine, in human plasma. Azelastine-(13)C, d(3) was used as internal standard. Azelastine, desmethylazelastine and the internal standard were extracted by a liquid-liquid extraction method and separation was performed under isocratic chromatographic condition. An abnormal signal loss issue for desmethylazelastine during method development was investigated and resolved. The developed method was precise and reproducible as shown by good intraday assay and interday assay precision (CV% 12.8%). The calibration curve was linear over a range of 10.0/10.0-1000/200 pg/mL for azelastine/desmethylazelastine. The method was successfully applied to a pilot bioequivalence study subsequently.

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