title: Electrophoretic stacking for sensitive determination of antibiotic ceftazidime in human blood and microdialysates from diabetic foot.
abstract: An electrophoretic stacking method has been developed for monitoring the therapeutic level of the antibiotic ceftazidime in blood plasma and microdialysates taken from peripheral soft tissues of the lower limbs of patients with diabetic foot syndrome. The biological samples are treated by addition of acetonitrile in an amount of 75% v/v and injected into a capillary in a large volume; after turning on the separation voltage, the residual acetonitrile is forced out of the capillary by the application of hydrodynamic pressure. The clinical samples were separated in an optimised background electrolyte composed of 50 mM chloroacetic acid +20% v/v methanol +0.5% v/v INST coating solution. The attained LOD for ceftazidime equalled 0.42 μg mL-1(0.8 μM) and the migration time equalled 3.75 min when using a 25 μm capillary with minimum length of 31.5 cm. The separation was controlled by a maximum voltage of +30 kV and the movement of the analyte was accelerated by a pressure of 50 mbar. The RSD values for intra-day repeatability of the migration time and peak area are 0.14% and 3.8%, respectively; the inter-day values equalled 0.25% for the migration time and 7.3% for peak area, respectively. Pharmacological studies revealed that ceftazidime passes from the blood circulation to the peripheral tissues of the lower limbs with an efficiency of 20%. The introduction of CE control of ceftazidime level in diabetic foot represents a very important improvement in achieving the targeted therapeutic effect.
authors.affiliation: Charles University in Prague, Third Faculty of Medicine, Department of Biochemistry, Cell and Molecular Biology, Ruská 87, 100 00 Prague 10, Czech Republic. Electronic address: petr.tuma@lf3.cuni.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Tůma
authors.affiliation: Charles University in Prague, Third Faculty of Medicine, Department of Biochemistry, Cell and Molecular Biology, Ruská 87, 100 00 Prague 10, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Jaček
authors.affiliation: Institute for Clinical and Experimental Medicine, Diabetes Center, Vídeňská 1958, 140 21 Prague 4, Czech Republic.
authors.forename: Vladimíra
authors.initials: V
authors.lastname: Fejfarová
authors.affiliation: Charles University in Prague, Third Faculty of Medicine, Center for Research on Diabetes, Metabolism and Nutrition, Ruská 87, Prague 10000, Czech Republic; 2nd Internal Medicine Department, Vinohrady Teaching Hospital, Šrobárova 50, Prague 10034, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Polák
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000097:blood; D002442:Ceftazidime / Q000032:analysis* / Q000097:blood; D017719:Diabetic Foot / Q000097:blood*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D017551:Microdialysis
chemical_list: D000900:Anti-Bacterial Agents; D002442:Ceftazidime
keywords: Antibiotics; Capillary electrophoresis; Ceftazidime; Diabetic foot syndrome; Microdialysis; Sample stacking