Expedient liquid chromatographic method with fluorescence detection for montelukast sodium in micro-samples of plasma.

This study describes an expedient assay for the analysis of the asthma medication, montelukast sodium (Singulair, MK-0476), in human plasma samples. After a simple extraction of the plasma, the drug and internal standard, quinine bisulfate, were measured by HPLC. The chromatographic system consisted of a single pump, a refrigerated autosampler, a C8 4-microm particle size radial compression cartridge at 40 degrees C and a fluorescence detector with the excitation and emission wavelengths set at 350 and 400 nm, respectively.

Sensitive assay for the determination of cefazolin or ceftriaxone in plasma utilizing LC.

A rapid, specific and very sensitive liquid chromatographic assay using standard ultraviolet detection has been developed to measure cefazolin (CFZ) or ceftriaxone (CFX) in small samples (200 microl) of plasma using either drug as the internal standard for measurement of the other. A rapid extraction was performed using C18 bonded Sep Pak cartridges with high extraction efficiency for both drugs. The chromatographic system employed the use of a Nova-Pak C18 4-microm cartridge with a radial compression system preceded by a Guard-Pak with a C18 insert.

Pharmacokinetics of S- and R-enantiomers of aminoglutethimide following oral administration of racemic drug in breast cancer patients.

This study was undertaken to examine the pharmacokinetics of both enantiomers of AG--that is, (R-AG) and (S-AG) and respective acetyl metabolites, R-AcAG and S-AcAG--in breast cancer patients. Six patients received a single dose (500 mg) of the racemic drug, and serial plasma samples and urine were collected over a 48-hour period. R-AG, S-AG, R-AcAG, and S-AcAg were measured simultaneously by high-performance liquid chromatography using two serial chiral separation columns with ultraviolet detection.

Liquid chromatographic separation and measurement of optical isomers of aminoglutethimide and its acetyl metabolite in plasma, saliva, and urine.

An accurate and specific liquid chromatographic method for the separation and analysis of the R(+) and S(-) enantiomers of both aminoglutethimide (AG) and its acetylated metabolite (AcAG) in plasma, saliva, and urine is described. The separation was achieved by use of two serial Chiralcel OD columns [cellulose tris(3,5-dimethylphenyl carbamate)] with a mixture of hexane/isopropanol/methanol (65:17.5:17.