Suitability of automated capillary and micro liquid chromatography for routine determination of drugs in human plasma samples from clinical pharmacokinetic investigations

✍ Scribed by Malavasi, Bruno ;Ascalone, Vittorio

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 768 KB
• Volume: 19
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240190906

✦ Synopsis

Abstract

One of the most widely acclaimed features of capillary and microcolumn LC, in comparison with conventional HPLC, is the enormous increase in mass sensitivity. Nevertheless, application of capillary and micro LC in quantitative trace bioanalysis, characterized by weak analyte concentrations in complex matrices, can only be of any practical utility if large sample volumes can be injected onto the columns without affecting chromatographic resolution and efficiency.

Two applications of large volume injection in a non‐eluting solvent (on‐column focusing) for the quantitative analysis of drugs in biological fluids on both capillary and micro chromatographic systems are presented: the first example deals with a new selective H~1~‐antihistaminic drug, mizolastine, the second one with a well known calcium antagonist, diltiazem, and its main metabolites. For both compounds, results obtained on micro and capillary LC in comparison with conventional HPLC are reported. The results demonstrate that when conventional HPLC methods are transformed into either micro or capillary LC techniques, they gain in sensitivity. By means of an on‐column focusing technique, it is possible to increase the sensitivity 3–5 fold in comparison to conventional HPLC methods, but not 50–60 fold as obtained on synthetic drug solutions. Column robustness, handiness, reproducibility, and suitability of micro systems for routine bioanalysis are discussed for both capillary and micro LC columns, as well as limits of the technique in trace organic analysis problems.