Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children.
We have developed a sensitive, selective and reproducible reversed-phase high-performance liquid chromatography method coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) for the simultaneous quantification of midazolam (MDZ) and its major metabolite, 1'-hydroxymidazolam (1...
| Main Authors: | , , , , , |
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| Formato: | Journal article |
| Idioma: | English |
| Publicado: |
2005
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| _version_ | 1826272557669548032 |
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| author | Muchohi, SN Ward, SA Preston, L Newton, C Edwards, G Kokwaro, G |
| author_facet | Muchohi, SN Ward, SA Preston, L Newton, C Edwards, G Kokwaro, G |
| author_sort | Muchohi, SN |
| collection | OXFORD |
| description | We have developed a sensitive, selective and reproducible reversed-phase high-performance liquid chromatography method coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) for the simultaneous quantification of midazolam (MDZ) and its major metabolite, 1'-hydroxymidazolam (1'-OHM) in a small volume (200 microl) of human plasma. Midazolam, 1'-OHM and 1'-chlordiazepoxide (internal standard) were extracted from alkalinised (pH 9.5) spiked and clinical plasma samples using a single step liquid-liquid extraction with 1-chlorobutane. The chromatographic separation was performed on a reversed-phase HyPURITY Elite C18 (5 microm particle size; 100 mm x 2.1mm i.d.) analytical column using an acidic (pH 2.8) mobile phase (water-acetonitrile; 75:25% (v/v) containing formic acid (0.1%, v/v)) delivered at a flow-rate of 200 microl/min. The mass spectrometer was operated in the positive ion mode at the protonated-molecular ions [M+l]+ of parent drug and metabolite. Calibration curves in spiked plasma were linear (r2 > or = 0.99) from 15 to 600 ng/ml (MDZ) and 5-200 ng/ml (1'-OHM). The limits of detection and quantification were 2 and 5 ng/ml, respectively, for both MDZ and 1'-OHM. The mean relative recoveries at 40 and 600 ng/ml (MDZ) were 79.4+/-3.1% (n = 6) and 84.2+/-4.7% (n = 8), respectively; for 1'-OHM at 30 and 200 ng/ml the values were 89.9+/-7.2% (n = 6) and 86.9+/-5.6% (n = 8), respectively. The intra-assay and inter-assay coefficients of variation (CVs) for MDZ were less than 8%, and for 1'-OHM were less than 13%. There was no interference from other commonly used antimalarials, antipyretic drugs and antibiotics. The method was successfully applied to a pharmacokinetic study of MDZ and 1'-OHM in children with severe malaria and convulsions following administration of MDZ either intravenously (i.v.) or intramuscularly (i.m.). |
| first_indexed | 2024-03-06T22:14:26Z |
| format | Journal article |
| id | oxford-uuid:52ea8bbd-f8e2-4202-a6a3-6ca5f2c6d5e7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:14:26Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:52ea8bbd-f8e2-4202-a6a3-6ca5f2c6d5e72022-03-26T16:28:26ZDetermination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:52ea8bbd-f8e2-4202-a6a3-6ca5f2c6d5e7EnglishSymplectic Elements at Oxford2005Muchohi, SNWard, SAPreston, LNewton, CEdwards, GKokwaro, GWe have developed a sensitive, selective and reproducible reversed-phase high-performance liquid chromatography method coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) for the simultaneous quantification of midazolam (MDZ) and its major metabolite, 1'-hydroxymidazolam (1'-OHM) in a small volume (200 microl) of human plasma. Midazolam, 1'-OHM and 1'-chlordiazepoxide (internal standard) were extracted from alkalinised (pH 9.5) spiked and clinical plasma samples using a single step liquid-liquid extraction with 1-chlorobutane. The chromatographic separation was performed on a reversed-phase HyPURITY Elite C18 (5 microm particle size; 100 mm x 2.1mm i.d.) analytical column using an acidic (pH 2.8) mobile phase (water-acetonitrile; 75:25% (v/v) containing formic acid (0.1%, v/v)) delivered at a flow-rate of 200 microl/min. The mass spectrometer was operated in the positive ion mode at the protonated-molecular ions [M+l]+ of parent drug and metabolite. Calibration curves in spiked plasma were linear (r2 > or = 0.99) from 15 to 600 ng/ml (MDZ) and 5-200 ng/ml (1'-OHM). The limits of detection and quantification were 2 and 5 ng/ml, respectively, for both MDZ and 1'-OHM. The mean relative recoveries at 40 and 600 ng/ml (MDZ) were 79.4+/-3.1% (n = 6) and 84.2+/-4.7% (n = 8), respectively; for 1'-OHM at 30 and 200 ng/ml the values were 89.9+/-7.2% (n = 6) and 86.9+/-5.6% (n = 8), respectively. The intra-assay and inter-assay coefficients of variation (CVs) for MDZ were less than 8%, and for 1'-OHM were less than 13%. There was no interference from other commonly used antimalarials, antipyretic drugs and antibiotics. The method was successfully applied to a pharmacokinetic study of MDZ and 1'-OHM in children with severe malaria and convulsions following administration of MDZ either intravenously (i.v.) or intramuscularly (i.m.). |
| spellingShingle | Muchohi, SN Ward, SA Preston, L Newton, C Edwards, G Kokwaro, G Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children. |
| title | Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children. |
| title_full | Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children. |
| title_fullStr | Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children. |
| title_full_unstemmed | Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children. |
| title_short | Determination of midazolam and its major metabolite 1'-hydroxymidazolam by high-performance liquid chromatography-electrospray mass spectrometry in plasma from children. |
| title_sort | determination of midazolam and its major metabolite 1 hydroxymidazolam by high performance liquid chromatography electrospray mass spectrometry in plasma from children |
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