Claudio Giachetti

Simultaneous determination of atenolol and chlorthalidone in plasma by high-performance liquid chromatography application to pharmacokinetic studies in man

An HPLC method developed to detect in a single run both atenolol and chlorthalidone, extracted from plasma, using two detectors (UV for chlorthalidone and fluorometric for atenolol) connected in series, is described. The drugs were separated on an ODS column at room temperature using a 0.05 M sodium dodecyl sulphate in phosphate buffer (pH 5.8)-n-propanol (95:5, v/v) solution, delivered at a flow-rate of 1.3 ml/min. Having ascertained the sensitivity (10 ng/ml of both drugs) and the intra-day reproducibility (pre-study validation), the reliability of the method was verified by inter-day assays (within-study validation) carried out during the analysis of plasma samples collected from healthy volunteers after single-dose treatment with atenolol+chlorthalidone tablets (pharmaceutical preparations containing 100+25 mg and 50+12.5 mg of the two drugs, respectively).

Separation of non-steroidal anti-inflammatory agents by high-resolution gas chromatography. Preliminary trials to perform pharmacokinetic studies

Abstract To assess the suitability of capillary gas chromatography for pharmacokinetic studies, a separation method was developed that is applicable to ten of the major organic acids widely used as analgesics and/or anti-inflammatory agents. The separation was performed by high-resolution gas chromatography on a 15-m SE-52 glass column before and after addition of the acids to plasma samples. The reliability of the method was analysed for each group of organic acids.

Gas chromatographic-mass spectrometric determination of ethyl carbamate as the xanthylamide derivative in Italian aqua vitae (grappa) samples.

A selective reaction of ethyl carbamate (urethane) and methyl urethane (urethylane), as internal standard, with xanthydrol was effected to detect urethane after extraction from Italian aqua vitae (grappa) samples. The xanthylamides formed were determined by gas chromatography-mass spectrometry in the selected ion monitoring mode on an apolar DB 5 silica column. The linearity of the method was tested from 10 to 1000 micrograms/l, with a detection limit of 1 micrograms/l.