Gas chromatographic determination of clioquinol (Vioform) in human plasma

Determination of chinoform in biological fluids and nervous tissues of the dog by gas chromatography-mass spectrometry

A sensitive gas chromatographic-mass spectrometric method for the determination of 5-chloro-7-iodo-8-hydroxyquinoline (chinoform, clioquinol) in biological fluids and nervous tissues is described. Chinoform was converted into the pentafluorobenzyl ether, which was separated on a 10% Dexsil 300GC column and determined by the use of chinoform-d4 as an internal standard. The clean-up of chionoform in plasma and urine was efficiently achieved by extracting with benzene, while the drug in the tissue was pretreated successively by extraction with 12.5% v/v pyridine-benzene, separation on a Clin-Elut cartridge and adsorption on alumina. The quantitation limit of chinoform was 100 pg, and the recovery rates of chinoform added to plasma and tissue were 98% and 92%, respectively. The chinoform levels in biological fluids and tissues in dogs after prolonged administration of the drug at a dose of 400 mg/kg/day were measured by the proposed method. The plasma level and tissue distribution of chinoform are also discussed.

Drug level monitoring: chromatography of some minor groups of drugs

Some important facts about the chromatographic separation of a number of selected categories of drugs are summarized. The data refer to the chromatographic method of choice, stationary phase, mobile phase (carrier gas), detection procedure and (where available) method sensitivity. Also, fundamental instrumental parameters, namely injector, column and detector temperature, carrier gas and mobile phase flow-rate and gradient set-up are reported here. In all cases also the source material used for analysis is specified. The data are presented in table form, each table dealing with a particular category of drugs. The following categories of drugs are being dealt with: anthelmintics, antiarteriosclerotics, antibacterials, anticholinergics and cholinergics, anticoagulants, antidiabetics, antiemetics, antimycotics, antihistamines, antimalarials, antiparasitics, antiparkinsonics, antitussives, antiulcer drugs, antiviral compounds, appetite depressants and immunosuppressives.

Derivatization reactions in the gas—liquid chromatographic analysis of drugs in biological fluids

Alkylation, acylation, silylation and other derivatization reactions applied to the gas chromatographic analysis of drugs in biological matrices are reviewed. Reaction conditions are discussed in relation to reaction mechanisms. Detector-oriented labelling of drugs, and derivatization with chiral reagents for the separation of enantiomers are surveyed. Data on the sample clean-up, derivatization and GLC analysis of more than 300 drugs and related compounds are listed.

Analysis of iodochlorhydroxyquin in biological materials by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic system using a mobile phase of 0.05 M phosphoric acid--methanol (30:70) was developed for determination of iodochlorhydroxyquin (clioquinol, I) in biological material. I was extracted from samples with diethyl ether. Conjugates of I were hydrolyzed to free I and extracted by the same method. The ether phases were evaporated to dryness, reconstituted in the mobile phase and chromatographed using a microparticulate C18 column, a pre-column and a UV detector set at 256 nm. Quantitation of I in the range of 0.20-2.0 micrograms/ml of urine, 0.50-2.0 micrograms/g of liver, and 0.25-2.0 micrograms/g of feces was obtained with coefficients of variation of 0.02, 0.05, and 0.06, respectively. The detection limit of I was 0.2 micrograms. Extensive absorption of I upon topical application to dogs was also demonstrated.

The analytical control of the composition of creams

The analysis without prior sample clean-up of promethazine hydrochloride or clioquinol in commercially available creams has been investigated using UV-spectrophotometry and titrimetric methods. The results were compared with those obtained by GLC and HPLC. Although in some cases the active drug could be determined satisfactorily using the comparatively non-selective UV-absorbance or titrimetric methods, these methods were found to be reliable only when applied to creams for which the qualitative and quantitative composition was completely known. Without prior sample clean-up, these methods will therefore be of interest mainly for process control purposes in manufacturing.