Acta Pharm. 56
(2006) 481-488
Short communication
Optimized determination
of lorazepam in human serum with extraction and
high-performance liquid chromatographic analysis
AMIR G. KAZEMIFARD¹,*,
KHEIROLLAH GHOLAMI ² and ALIREZA DABIRSIAGHI¹
kazemifa@sina.tums.ac.ir
¹Faculty of Pharmacy,
²Department of Clinical
Pharmacy,
Accepted
The
present research was designated to evaluate a rapid and sensitive method for
determining low concentrations of the highly active drug lorazepam
in serum. Isolation of the drug from biological fluid after addition of nordazepam as the internal standard was achieved using a
simple liquid-liquid extraction with dichloromethane and the extracted
compounds were quantified by high-performance liquid chromatography. Chromatographic
separation on a reversed phase column containing a stationary phase with low silanol activity resulted in a perfectly symmetrical peak
with a tailing factor of 1.0. The limit of quantitation
in serum is 2.5 ng mL-1
for both lorazepam and internal standard. The
procedure is rapid and sensitive enough for determination of lorazepam in serum.
Keywords: lorazepam,
serum, high-performance liquid chromatography, peak tailing