Measurement of total and free docetaxel concentration in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry.
Docetaxel is a semi-synthetic taxane with cytotoxic anti-neoplastic activity and, currently used as anticancer agent in several types of cancer. Docetaxel is highly bound to plasma proteins, and this significantly determines its clearance and activity. Therefore, measurement of free docetaxel in plasma is pharmacologically important when pharmacokinetics is investigated. We developed and validated chromatographic methods by ultra-performance liquid chromatography-tandem mass spectrometry to measure total and free docetaxel concentration in human plasma. The final validated methods involved liquid-liquid extraction followed by dryness under nitrogen evaporation. To measure free docetaxel concentration, sample preparation was preceded by ultrafiltration. Chromatographic separation was achieved using an Acquity(®) UPLC(®) BEH™ (2.1×100 mm id, 1.7 μm) reverse-phase C18 column at a flow rate of 0.4 mL/min, using isocratic elution mode containing ammonium acetate/formic acid in water/methanol (30:70 v/v) as mobile phase. Docetaxel and its internal standard (paclitaxel) were detected by electrospray ionization mass spectrometry in positive ion multiple reaction monitoring mode using mass-to-charge (m/z) transitions of 808.3→527.0 (quantifier) and 808.3→509.0 (qualifier); and 854.3→569.0 (quantifier) and 854,3→509,0 (qualifier), respectively. The run time per sample was 3.5 min. The limits of quantification were 1,95 and 0.42 μg/L and linearity was observed between 1.95 and 1000 and 0.42-100 μg/L for total and free docetaxel, respectively. Coefficients of variation and absolute relative biases were less than 13.8% and 10.0%. Recovery values were greater than 79.4%. Evaluation of the matrix effect showed ion suppression and no carry-over was observed. The validated methods could be useful for both therapeutic drug monitoring and pharmacokinetic studies. They could be applied to daily clinical laboratory practice to measure the concentration of total and free docetaxel in plasma.
Laboratori Clínic Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain. Electronic address: raulr@bellvitgehospital.cat.
Raül
R
Rigo-Bonnin
Pharmacy Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
Sara
S
Cobo-Sacristán
Pharmacy Department, IDIBELL, Catalan Institute of Oncology, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain.
Núria
N
Gonzalo-Diego
Department of Biopharmaceutics and Pharmacokinetics, School of Pharmacy, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.
Helena
H
Colom
Pharmacy Department, IDIBELL, Catalan Institute of Oncology, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain.
Carmen
C
Muñoz-Sánchez
Catalan Institute of Oncology, IDIBELL, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain.
Ander
A
Urruticoechea
Catalan Institute of Oncology, IDIBELL, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain.
Catalina
C
Falo
Laboratori Clínic Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
Pedro
P
Alía
D000970:Antineoplastic Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D000077143:Docetaxel; D006801:Humans; D053719:Tandem Mass Spectrometry / Q000379:methods*; D043823:Taxoids / Q000097:blood*; D014462:Ultrafiltration / Q000379:methods
D000970:Antineoplastic Agents; D043823:Taxoids; D000077143:Docetaxel
Free docetaxel; Paclitaxel; Total docetaxel; UPLC–MS/MS; Ultrafiltration