Underivatized measurement of bromazepam by gas chromatography—electron-capture detection with application to single-dose pharmacokinetics

Friedman, H.; Greenblatt, David J.; Burstein, Ethan S.; Ochs, Hermann R.

doi:10.1016/s0378-4347(00)80745-8

Cited by 6 publications

(2 citation statements)

References 6 publications

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“…The bromazepam peak plasma concentration ( C max ), the time to achieve this concentration ( T max ) and the terminal half‐life ( T 1/2 ) were similar to those reported in the literature 4…”

Section: Resultssupporting

confidence: 80%

“…In clinical and forensic toxicology, several chromatographic methods have been described for the determination of bromazepam in human biosamples (whole blood, plasma or serum), including gas/liquid chromatography coupled to electron‐capture detection (GLC/ECD),3 gas chromatography coupled to electron‐capture detection (GC/ECD),4, 5 high‐performance liquid chromatography coupled to UV detection (HPLC/UV),6–15 gas chromatography coupled to mass spectrometry (GC/MS),16–18 gas chromatography coupled to tandem mass spectrometry (GC/MS/MS)19 and liquid chromatography coupled to mass spectrometry (LC/MS) 20, 21. Chromatographic techniques are commonly used to quantify bromazepam in a specimen initially screened by a immunoassay‐based method 22…”

Section: Introductionmentioning

confidence: 99%

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Bromazepam determination in human plasma by high‐performance liquid chromatography coupled to tandem mass spectrometry: a highly sensitive and specific tool for bioequivalence studies

Laurito¹,

Mendes²,

Santagada³

et al. 2004

J. Mass Spectrom.

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A rapid, sensitive and specific method to quantify bromazepam in human plasma using diazepam as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using diethyl ether-hexane (80 : 20, v/v). The extracts were analyzed by high-performance liquid chromatography (HPLC) coupled to electrospray tandem mass spectrometry (MS/MS). Chromatography was performed isocratically on a Genesis C(18) analytical column (100 x 2.1 mm i.d., film thickness 4 microm). The method had a chromatographic run time of 5.0 min and a linear calibration curve over the range 5.0-150 ng ml(-1) (r(2) > 0.9952). The limit of quantification was 5 ng ml(-1). This HPLC/MS/MS procedure was used to assess the bioequivalence of two bromazepam 6 mg tablet formulations (bromazepam from Medley SA Indústria Farmacêutica as the test formulation and Lexotan from Produtos Roche Químico e Farmacêutico SA as the reference formulation). A single 6 mg dose of each formulation was administered to 24 healthy volunteers (12 males and 12 females). The study was conducted using an open, randomized, two-period crossover design with a 3 week washout interval. Since the 90% CI for C(max), AUC(last), AUC(0-240 h) (linear) and AUC((0- infinity )) ratios were all inside the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that the bromazepam formulation from Medley is bioequivalent to the Lexotan formulation for both the rate and the extent of absorption.

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Section: Resultssupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Bromazepam determination in human plasma by high‐performance liquid chromatography coupled to tandem mass spectrometry: a highly sensitive and specific tool for bioequivalence studies

Laurito¹,

Mendes²,

Santagada³

et al. 2004

J. Mass Spectrom.

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Actual versus reported benzodiazepine usage by medical outpatients

Ochs

Miller

Greenblatt

et al. 1987

Eur J Clin Pharmacol

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Benzodiazepines are widely prescribed, and in 1979 almost 10% of the adult population was taking them. Prior studies of outpatient usage of benzodiazepines have relied on survey or prescription data, which may be confounded by noncompliance. To determine the actual use of benzodiazepines, plasma benzodiazepine concentrations were measured in 225 consecutive outpatients from a university cardiology outpatient service. Self reports indicated that the great majority of the patients (191) were taking at least one medicine, and 70 reported being on a psychotropic drug. Seventy-seven patients reported taking benzodiazepines, the majority being on bromazepam (20), diazepam (26) or oxazepam (19). In 25 of those 77 patients, the reported drug could not be detected in plasma. Conversely, in 10 of the 225 patients, benzodiazepines which were not reported were detected (diazepam or flurazepam). Of those taking benzodiazepines, many had a low concentration, suggesting intermittent rather than regular use. Thus, many patients for whom benzodiazepines are prescribed take them irregularly, and a small group uses them without reporting their prescription. These findings have implications for the clinical presentation of illness and for the possibility of drug interactions.

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