Profiling Docetaxel in Plasma and Urine Samples from a Pediatric Cancer Patient Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with LC-MS/MS.

In recent years, therapeutic drug monitoring (TDM) has been applied in docetaxel (DOC)-based anticancer therapy to precisely control various pharmacokinetic parameters, including the concentration of DOC in biofluids (e.g., plasma or urine), its clearance, and its area under the curve (AUC). The ability to determine these values and to monitor DOC levels in biological samples depends on the availability of precise and accurate analytical methods that both enable fast and sensitive analysis and can be implemented in routine clinical practice. This paper presents a new method for isolating DOC from plasma and urine samples based on the coupling of microextraction and advanced liquid chromatography with tandem mass spectrometry (LC-MS/MS). In the proposed method, biological samples are prepared via ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) using ethanol (EtOH) and chloroform (Chl) as the desorption and extraction solvents, respectively. The proposed protocol was fully validated according to the Food and Drug Administration (FDA) and the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) requirements. The developed method was then applied to monitor the DOC profile in plasma and urine samples collected from a pediatric patient suffering from cardiac angiosarcoma (AS) with metastasis to lungs and mediastinal lymph nodes, who was receiving treatment with DOC at a dose of 30 mg/m2 body surface area. Due to the rarity of this disease, TDM was carried out to determine the exact levels of DOC at particular time points to ascertain which levels were conducive to maximizing the treatment's effectiveness while minimizing the drug's toxicity. To this end, the concentration-time profiles of DOC in the plasma and urine samples were determined, and the levels of DOC at specific time intervals up to 3 days after administration were measured. The results showed that DOC was present at higher concentrations in the plasma than in the urine samples, which is due to the fact that this drug is primarily metabolized in the liver and then eliminated with the bile. The obtained data provided information about the pharmacokinetic profile of DOC in pediatric patients with cardiac AS, which enabled the dose to be adjusted to achieve the optimal therapeutic regimen. The findings of this work demonstrate that the optimized method can be applied for the routine monitoring of DOC levels in plasma and urine samples as a part of pharmacotherapy in oncological patients.

Monitoring of sirolimus in the whole blood samples from pediatric patients with lymphatic anomalies.

In recent years, off-label use of sirolimus (SIR) has been gaining attention in the clinical practice. However, since it is critical to achieve and maintain therapeutic blood levels of SIR during treatment, the regular monitoring of this drug in individual patients must be implemented, especially in off-label indications of this drug. In this article, a fast, simple, and reliable analytical method for determining SIR levels in whole blood samples is proposed. Sample preparation based on dispersive liquid-liquid microextraction (DLLME) followed by liquid chromatography-mass spectrometry (LC-MS/MS) was fully optimized toward the analysis of SIR and proposed as a fast, simple, and reliable analytical method for determining the pharmacokinetic profile of SIR in whole-blood samples. In addition, the practical applicability of the proposed DLLME-LC-MS/MS method was evaluated by analyzing the pharmacokinetic profile of SIR in whole blood samples obtained from two pediatric patients suffering from lymphatic anomalies, receiving this drug as off-label clinical indication. The proposed methodology can be successfully applied in routine clinical practice for the fast and precise assessment of SIR levels in biological samples, thus allowing SIR dosages to be adjusted in real time during pharmacotherapy. Moreover, the measured SIR levels in the patients indicate the need for monitoring between doses to ensure the optimal pharmacotherapy of patients.

Sensitive Analysis of Idarubicin in Human Urine and Plasma by Liquid Chromatography with Fluorescence Detection: An Application in Drug Monitoring.

A new approach for the sensitive, robust and rapid determination of idarubicin (IDA) in human plasma and urine samples based on liquid chromatography with fluorescence detection (LC-FL) was developed. Satisfactory chromatographic separation of the analyte after solid-phase extraction (SPE) was performed on a Discovery HS C18 analytical column using a mixture of acetonitrile and 0.1% formic acid in water as the mobile phase in isocratic mode. IDA and daunorubicin hydrochloride used as an internal standard (I.S.) were monitored at the excitation and emission wavelengths of 487 and 547 nm, respectively. The method was validated according to the FDA and ICH guidelines. The linearity was confirmed in the range of 0.1-50 ng/mL and 0.25-200 ng/mL, while the limit of detection (LOD) was 0.05 and 0.125 ng/mL in plasma and urine samples, respectively. The developed LC-FL method was successfully applied for drug determinations in human plasma and urine after oral administration of IDA at a dose of 10 mg to a patient with highly advanced alveolar rhabdomyosarcoma (RMA). Moreover, the potential exposure to IDA present in both fluids for healthcare workers and the caregivers of patients has been evaluated. The present LC-FL method can be a useful tool in pharmacokinetic and clinical investigations, in the monitoring of chemotherapy containing IDA, as well as for sensitive and reliable IDA quantitation in biological fluids.

Development and validation of a high-performance liquid chromatographic method with a fluorescence detector for the analysis of epirubicin in human urine and plasma, and its application in drug monitoring.

The aim of the work was to develop a simple, sensitive and accurate liquid chromatography with fluorescence detection (LC-FL) method for the determination of epirubicin in human urine and plasma. Solid phase extraction with HLB cartridges and mixture of dichloromethane:2-propanol:methanol (2:1:1, v/v/v) as the eluent, was used to prepare the samples. The chromatographic analysis was carried out on a Synergi Hydro-RP column with a mobile phase consisting of 40 mM phosphate buffer (pH 4.1) and acetonitrile (69:31, v/v). Epirubicin was monitored at 497 nm and 557 nm for excitation and emission wavelengths, respectively. Validation data confirmed that the limit of detection and limit of quantification was 0.25 ng/mL and 0.5 ng/mL in both matrices. Next, the optimized LC-FL method was applied to determine the level of epirubicin in real samples taken from a 19-year-old patient with metastatic alveolar rhabdomyosarcoma (RMA) to create a drug profile. Plasma and urine samples were collected for 24 h after the end of a 6-hour infusion of epirubicin. The obtained results confirmed that the optimized and validated LC-FL method can be successfully used in drug monitoring therapy, pharmacokinetic and clinical studies. Moreover, the current work is also drawing attention to the relatively high level of epirubicin in the patient urine, which requires compliance with the safety rules in contact with this biological fluid by both medical staff and others, e.g. family members.

Optimization of LC method for the quantification of doxorubicin in plasma and urine samples in view of pharmacokinetic, biomedical and drug monitoring therapy studies.

A simple, rapid, reliable and sensitive method based on liquid chromatography with fluorescence detection (LC-FL) for the quantification of doxorubicin (DOX) in human plasma and urine samples was developed. The assay was carried out after the solid-phase extraction procedure (SPE) with hydrophilic-lipophilic balance (HLB) cartridges, and with daunorubicin hydrochloride (DAU) used as the internal standard. Chromatographic separation was performed on a Discovery HS C18 column in isocratic elution mode, and the detection of the analytes set at excitation and emission wavelengths of 487 and 555 nm, respectively. The developed LC-FL method has been validated for accuracy, precision, selectivity, linearity, recovery and stability. The limits of detection and quantification for DOX were 0.5 and 1 ng/mL in both biological fluids, respectively. Linearity was confirmed in the range of 1-1000 ng/mL and 0.001-25 µg/mL in plasma and urine samples, respectively, with a correlation coefficient greater than 0.9994. The proposed LC-FL method is selective, precise and accurate, and has been successfully applied for drug monitoring in pediatric cancer patients treated with DOX as a component of OEPA (Oncovin (Vincristine)-Etoposide-Prednisone-Adriamycin) and IOA (Ifosfamide-Oncovin-Adriamycin) chemotherapeutic schemes. Moreover, real exposure of hospital personnel to the anthracycline drugs in plasma and urine was evaluated in clinical practice.