Fast isocratic high-performance liquid chromatographic assay method for the simultaneous determination of gabapentin and vigabatrin in human serum.
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Acetates↗
Biomedical subjects
D F Chollet
Publications and source records attributed to D F Chollet.
Therapeutic drug monitoring of tacrine: simple and fast high-performance liquid chromatography assay method for its determination in human plasma.
A new high-performance liquid chromatography (HPLC) assay method was developed for the therapeutic monitoring of tacrine. The method involved a simple protein precipitation by means of either acetonitrile or cold methanol followed by a fast isocratic separation on a CN column eluted in reversed-phase mode. The entire sample preparation took place in an HPLC vial and no further liquid transfer was required. The validation data showed that the assay method was precise, accurate, and robust. Analysis of more than 1,000 plasma samples collected from patients with Alzheimer disease demonstrates the suitability of the assay.
Calibration↗
Gas chromatography-mass spectrometry assay method for the therapeutic drug monitoring of the antiepileptic drug tiagabine.
A gas chromatography-mass spectrometry assay method suitable for the therapeutic drug monitoring of the antiepileptic drug tiagabine is described. Tiagabine and its desmethylated analogue used as internal standard were first extracted from serum by liquid-liquid extraction using an ethyl ether-isobutanol 98:2 mixture. Tiagabine and the internal standard were then methylated in the organic phase in presence of methanol by means of a safe and stable diazomethane derivative. After evaporation, the reconstituted extracts were chromatographed on a crosslinked phenyl methyl siloxane capillary column and detected by mass fragmentometry at m/z = 156. No other antiepileptic drug possibly administrated in polytherapy and no metabolite were found to interfere in the assay. The limit of quantification was 5 ng/ml. The precision and the accuracy were found to be suitable for the therapeutic drug monitoring of tiagabine.
Anticonvulsants↗
Simultaneous determination of the lactone and carboxylate forms of the camptothecin derivative CPT-11 and its metabolite SN-38 in plasma by high-performance liquid chromatography.
CPT-11 (irinotecan) and mainly its metabolite SN-38 are potent antitumor derivatives of camptothecin. As the active lactone forms of both CPT-11 and SN-38 exist in pH-dependent equilibrium with their respective less potent open-ring hydroxy acid species, the simultaneous monitoring of both forms of both compounds is relevant. CPT-11 and SN-38 derivatives have quite different fluorescence responses. In order to avoid any compromise on the wavelength setting, we developed chromatographic conditions allowing simple automated wavelength setting changes which have been prevented using existing methods involving conventional C18 columns. This was achieved by means of a Symmetry C18 column combined to a gradient elution program using acetonitrile and 75 mM ammonium acetate plus 7.5 mM tetrabutylammonium bromide at pH 6.4. The developed conditions allowed an elution order suitable for a simple automated wavelength change in respect to reliable peak integration. CPT-11 and SN-38 derivatives were detected at lambda ex=362 nm/lambda em=425 nm and lambda ex=375 nm/lambda em =560 nm, respectively. The developed method allowed the detection of amounts less than 3 pg of each derivative injected on column. The method was successfully applied to pharmacokinetic and toxicokinetic studies in rat and dog.
Animals↗
Determination of dimethindene in human tears by high-performance liquid chromatography.
A high-performance liquid chromatographic method is described for the determination of dimethindene in human tears. The tear samples were diluted in a 0.01 M hydrochloric acid-n-propanol mixture to prevent the irreversible adsorption of dimethindene. The diluted samples were directly injected into the chromatographic system to avoid sample pretreatment. The validation data demonstrate that the method is specific, precise and accurate within the calibration range of 12 to 1000 ng/ml dimethindene free base.
Anti-Allergic Agents↗
Determination of noscapine in human plasma using solid-phase extraction and high-performance liquid chromatography.
A simple, reliable high-performance liquid chromatographic (HPLC) method has been developed and validated for the determination of noscapine in human plasma. Noscapine and the internal standard, papaverine were quantitatively extracted from plasma onto disposable extraction columns by means of an automated off-line solid-phase extraction system and were separated onto a reversed-phase column. The method was found to be precise and accurate within the range 7.2-270 ng/ml. No endogenous compounds interfered with the assay.
Antitussive Agents↗