ABSTRACT
An improved high-performance liquid chromatographic method with UV detection at 313 nm has been developed for quantitation of ranitidine in 100 microliter of rat plasma over the range 25 to 1000 ng/ml. To each sample were added the internal standard (metiamide) and 2 M NaOH. After dichloromethane extraction, the nitrogen-dried extracts were reconstituted in the mobile phase of 0.01 M phosphate buffer-triethylamine-methanol-water (530:5:390:75 v/v). Chromatography on mu Bondapak C18 with quantitation by peak height ratios showed an analyte recovery of 97%; a limit of detection of 10 ng/ml; a precision of 1-10% and an accuracy of 1-5%. About 90 samples can be processed in 24 h.
Subject(s)
Chromatography, Liquid/methods , Ranitidine/blood , Animals , Rats , Ultraviolet RaysABSTRACT
Cimetidine, N"-cyano-N-methyl-N'-[2[[(5-methyl-1H-imidazol-4-yl) methyl]-thio]ethyl]guanidine, is a specific histamine H2-receptor antagonist drug that is widely used in medicine to treat gastric ulcer disease and other pathological hypersecretory states. To study the bioavailability of cimetidine, it was necessary to develop a rapid and reliable high-performance liquid chromatography procedure for quantitating the drug in body fluids. In this new procedure, cimetidine is adsorbed directly from urine or plasma, without prior clean-up, on to a mini-column prepacked with C18 material (Sep-Pak C18 cartridge). Acetonitrile is used to elute the drug, and the eluate is analyzed by high-performance reversed-phase liquid chromatography on a Partisil 10 ODS column, with an aqueous phosphate-methanol mixture as the mobile phase and UV detection at 228 nm. This method for analyzing cimetidine in body fluids is rapid, accurate and precise and differs from previously reported methods in that it eliminates the need for performing bothersome single or multiple, dualphase solvent extractions. Moreover, slight modifications in the composition of the mobile phase permit the simultaneous determination of cimetidine metabolites.
Subject(s)
Cimetidine/analysis , Guanidines/analysis , Chromatography, High Pressure Liquid/methods , Cimetidine/blood , Cimetidine/urine , HumansSubject(s)
Adrenergic beta-Antagonists/adverse effects , Jogging , Running , Humans , Physical ExertionABSTRACT
A total of 526 non-marijuana plant samples representing 427 different plant species were subjected to the RIM test (Rutgers Identification for Marijuana test). Although a few samples gave Fast Blue B reactive spots when examined by thin-layer chromatography, the spots could easily be distinguished from the marijuana cannabinoid spots. No plants were found to exhibit false positive results and hence the method is considered to be relatively specific for marijuana.
