High-Throughput Method for the Simultaneous Determination of Doxorubicin Metabolites in Rat Urine after Treatment with Different Drug Nanoformulations.

Doxorubicin (DOX) is one of the most effective cytotoxic agents against malignant diseases. However, the clinical application of DOX is limited, due to dose-related toxicity. The development of DOX nanoformulations that significantly reduce its toxicity and affect the metabolic pathway of the drug requires improved methods for the quantitative determination of DOX metabolites with high specificity and sensitivity. This study aimed to develop a high-throughput method based on high-performance liquid chromatography with fluorescence detection (HPLC-FD) for the quantification of DOX and its metabolites in the urine of laboratory animals after treatment with different DOX nanoformulations. The developed method was validated by examining its specificity and selectivity, linearity, accuracy, precision, limit of detection, and limit of quantification. The DOX and its metabolites, doxorubicinol (DOXol) and doxorubicinone (DOXon), were successfully separated and quantified using idarubicin (IDA) as an internal standard (IS). The linearity was obtained over a concentration range of 0.05-1.6 µg/mL. The lowest limit of detection and limit of quantitation were obtained for DOXon at 5.0 ng/mL and 15.0 ng/mL, respectively. For each level of quality control (QC) samples, the inter- and intra-assay precision was less than 5%. The accuracy was in the range of 95.08-104.69%, indicating acceptable accuracy and precision of the developed method. The method was applied to the quantitative determination of DOX and its metabolites in the urine of rats treated by novel nanoformulated poly(lactic-co-glycolic acid) (DOX-PLGA), and compared with a commercially available DOX solution for injection (DOX-IN) and liposomal-DOX (DOX-MY).

Machine learning algorithms to control concentrations of carbon nanocomplexes in a biological medium via optical absorption spectroscopy: how to choose and what to expect?

A solution of spectroscopic inverse problems, implying determination of target parameters of the research object via analysis of spectra of various origins, is an overly complex task, especially in case of strong variability of the research object. One of the most efficient approaches to solve such tasks is use of machine learning (ML) methods, which consider some unobvious information relevant to the problem that is present in the data. Here, we compare ML approaches to the problem of nanocomplex concentrations determination in human urine via optical absorption spectra, perform preliminary analysis of the data array, find optimal parameters for several of the most popular ML methods, and analyze the results.

Deep eutectic solvent synthesis of iron vanadate-decorated sulfur-doped carbon nanofiber nanocomposite: electrochemical sensing tool for doxorubicin.

Detection of anticancer drug (doxorubicin) using an electrochemical sensor is developed based on a transition metal vanadate's related carbon composite material. With an environmentally friendly process, we have synthesized a metal oxide composite of iron vanadate nanoparticle assembled with sulfur-doped carbon nanofiber (FeV/SCNF). The FeV/SCNF composite was characterized using XRD, TEM, FESEM with elemental mapping, XPS and EDS. In contrast to other electrodes reported in the literature, a much-improved electrochemical efficiency is shown by FeV/SCNF composite modified electrodes. Amperometric technique has been employed at 0.25 V (vs. Ag/AgCl) for the sensitive detection of DOX within a wide range of 20 nM-542.5 µM and it possesses enhanced selectivity in presence of common interferents. The modified electrochemical sensors show high sensitivity of 46.041 µA µM-1 cm-2. The newly developed sensor could be used for the determination of doxorubicin in both blood serum and drug formulations with acceptable results, suggesting its feasibility for real-time applications.

Assessment of workplace environmental contamination and occupational exposure to cisplatin and doxorubicin aerosols during electrostatic pressurized intraperitoneal aerosol chemotherapy.

BACKGROUND: Electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (ePIPAC) is a novel approach for intraperitoneal drug delivery. As ePIPAC using cisplatin and doxorubicin is performed in an operating room, the challenge is to safely deliver the chemotherapeutic aerosol intraperitoneally while preventing exposure to healthcare workers. The objective of this study was to describe cisplatin and doxorubicin workplace environmental contamination and healthcare worker exposure during ePIPAC. METHODS: Antineoplastic drugs concentrations of cisplatin and doxorubicin were measured in wipe samples from the operating room, and urine samples were collected from healthcare workers. The air samples were collected in order to detect Cisplatin contamination. Cisplatin was analysed by inductively coupled plasma-mass spectrometry and doxorubicin by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. RESULTS: No trace of cisplatin was found in the air. Cisplatin and doxorubicin were detected on the operating room floor, surfaces, devices and personal protective equipment even after a cleaning protocol. No traces of cisplatin or doxorubicin were found in the urine samples. CONCLUSION: In this study, no internal contamination was found in the ePIPAC surgical team even after implementing two successive ePIPAC procedures. These results showed the effectiveness of the individual and collective protective measures applied. However, the cleaning procedure during ePIPAC should be respected to limit environmental exposure to chemotherapy to cisplatin and doxorubicin during ePIPAC.

Nurses' internal contamination by antineoplastic drugs in hospital centers: a cross-sectional descriptive study.

OBJECTIVE: The aim of this study was to assess internal antineoplastic drugs (ADs) contamination in the nursing staff in French hospital centers, using highly sensitive analytical methods. METHODS: This cross-sectional study included nurses practicing in care departments where at least one of the five ADs studied was handled (5-fluorouracil, cyclophosphamide, doxorubicin, ifosfamide, methotrexate). The nurses study participation lasted 24 h including collection of three urine samples and one self-questionnaire. All urine samples were assayed by ultra-high-performance liquid chromatography-tandem mass spectrometry methods with very low value of the lower limit of quantification (LLOQ). RESULTS: 74 nurses were included, 222 urine samples and 74 self-questionnaires were collected; 1092 urine assays were performed. The percentage of nurses with internal AD contamination was 60.8% and low levels of urinary concentrations were measured. Regarding nurses with internal contamination (n = 45), 42.2% presented internal contamination by methotrexate, 37.8% by cyclophosphamide, 33.3% by ifosfamide, 17.8% by 5-fluorouracil metabolite and 6.7% by doxorubicine. Among the positive assays, 17.9% (n = 26/145) were not explained by exposure data from the self-questionnaire but this could be due to the skin contact of nurses with contaminated work surfaces. CONCLUSIONS: This study reported high percentage of nurses with internal ADs contamination. The low LLOQ values of the used analytical methods, allowed the detection of ADs that would not have been detected with the current published methods: the percentage of contamination would have been 17.6% instead of the 60.8% reported here. Pending toxicological reference values, urine ADs concentrations should be reduced as low as reasonably achievable (ALARA principle).

Sensitive analysis of doxorubicin and curcumin by micellar electromagnetic chromatography with a double wavelength excitation source.

Doxorubicin has been extensively used to treat cancers, and there are recent findings that the anticancer activities can be enhanced by curcumin. Although the two compounds have native fluorescence, they can hardly be quantified directly simultaneously using the laser-induced fluorescence (LIF) detection method. To avoid complex fluorescence derivatization and introduction of interfering components, a highly sensitive double wavelength excitation source LIF (D-W-Ex-LIF) detector composed of a 445-nm and 488-nm commercial laser diode was constructed to detect them simultaneously. Rhodamine 6G was selected as an internal standard, because its fluorescence can be excited at 445 nm and 488 nm. The native fluorescence of doxorubicin and curcumin and their resolution were enhanced by introducing mixed micelles. The optimal electrophoretic separation buffer was 10 mM borate buffer containing 20 mM Triton X-100, 5 mM sodium dodecyl sulfate, and 30% (v/v) methanol at pH 9.00. Therefore, the developed method was specific, accurate, and easily operable. Its limits of detection for doxorubicin and curcumin in human urine samples were 4.00 × 10-3 and 1.00 × 10-2 µg/mL, respectively, and the limits of quantification were 1.00 × 10-2 and 3.00 × 10-2 µg/mL, respectively. The recoveries were 94.9-109.1%. Graphical abstract.

A 96-Monolithic inorganic hollow fiber array as a new geometry for high throughput solid-phase microextraction of doxorubicin in water and human urine samples coupled with liquid chromatography-tandem mass spectrometry.

Innovations in extraction phases, extraction modes and hyphenated instrument configurations, are the most important issues to address for progress in the solid phase microextraction (SPME) methodology. In this regard, we have embarked on the development of a novel biocompatible 96-monolithic inorganic hollow fiber (96-MIHF) array as a new configuration for high-throughput SPME on a 96-well plate system. An arrangement of highly ordered 96 titania/Hydroxyapatite (TiO2/HAP) nanocomposite hollow fibers and corresponding stainless-steel needles on a Teflon plate holder were used as the extraction module. The inorganic hollow fibers were prepared via a rapid and reproducible template approach (Polypropylene hollow fiber) in combination with a sol-gel method in the presence of polyvinyl alcohol (PVA), as a network maker. The hollow fiber-shape sorbents were obtained with excellent precision by weight (RSD% = 4.98, n = 10) and length (RSD% = 1.08, n = 10) criteria. The proposed design can overcome a number of geometrically dependent drawbacks of conventional high-throughput SPME methods, mainly the ones related to sorbent amount and surface area due to possessing inner/outer surfaces without additional internal supports. The SPME platform, for the first time, was successfully applied for the extraction and preconcentration of doxorubicin from urine and water media without requiring sample preparation and free from significant matrix effect. The extracted analyte was analyzed by liquid chromatography-ion trap tandem mass spectrometry (LC-MS/MS). Highly satisfactory analytical figures of merit were obtained under optimized conditions. The limit of detection (LOD), limit of quantification (LOQ) and linearity of determination were 0.1 ng mL-1, 0.25 ng mL-1 and 0.25 to 4000 ng mL-1, respectively. The interday, intraday and inter sorbent precisions for three concentration levels ranged from 2.01 to 8.09 % (n = 3), 1.02 to 8.65 % (n = 5) and 0.99 to 1.02% (n = 15), respectively. The mean intra-well RSD value for 96 individual wells in 96-MIHF-SPME-LC-MS/MS (n = 3) at the medium concentration level was 7.81%.

Study protocol for the assessment of nurses internal contamination by antineoplastic drugs in hospital centres: a cross-sectional multicentre descriptive study.

INTRODUCTION: Antineoplastic drugs (AD) are potentially carcinogenic and/or reprotoxic molecules. Healthcare professionals are increasingly exposed to these drugs and can be potentially contaminated by them. Internal contamination of professionals is a key concern for occupational physicians in the assessment and management of occupational risks in healthcare settings. Objectives of this study are to report AD internal contamination rate in nursing staff and to identify factors associated with internal contamination. METHODS AND ANALYSIS: This trial will be conducted in two French hospital centres: University Hospital of Bordeaux and IUCT-Oncopole of Toulouse. The target population is nurses practicing in one of the fifteen selected care departments where at least one of the five studied AD is handled (5-fluorouracil, cyclophosphamide, doxorubicin, ifosfamide, methotrexate). The trial will be conducted with the following steps: (1) development of analytical methods to quantify AD urine biomarkers, (2) study of the workplace and organization around AD in each care department (transport and handling, professional practices, personal and collective protection equipments available) (3) development of a self-questionnaire detailing professional activities during the day of inclusion, (4) nurses inclusion (urine samples and self-questionnaire collection), (5) urine assays, (6) data analysis. ETHICS AND DISSEMINATION: The study protocol has been approved by the French Advisory Committee on the Treatment of Information in Health Research (CCTIRS) and by the French Data Protection Authority (CNIL). Following the opinion of the Regional Committee for the Protection of Persons, this study is outside the scope of the provisions governing biomedical research and routine care (n°2014/87). The results will be submitted to peer-reviewed journals and reported at suitable national and international meetings. TRIAL REGISTRATION NUMBER: NCT03137641.

An eco-friendly stability-indicating spectrofluorimetric method for the determination of two anticancer stereoisomer drugs in their pharmaceutical preparations following micellar enhancement: Application to kinetic degradation studies.

A new rapid and highly sensitive stability-indicating spectrofluorimetric method was developed for the determination of two stereoisomers anticancer drugs, doxorubicin (DOX) and epirubicin (EPI) in pure form and in pharmaceutical preparations. The fluorescence spectral behavior of DOX and EPI in a sodium dodecyl sulfate (SDS) micellar system was investigated. It was found that the fluorescence intensity of DOX and EPI in an aqueous solution of phosphate buffer pH4.0 and in the presence of SDS was greatly (about two fold) enhanced and the mechanism of fluorescence enhancement effect of SDS on DOX was also investigated. The fluorescence intensity of DOX or EPI was measured at 553nm after excitation at 497nm. The plots of fluorescence intensity versus concentration were rectilinear over a range of 0.03-2µg/mL for both DOX and EPI with good correlation coefficient (r>0.999). High sensitivity to DOX and EPI was attained using the proposed method with limits of detection of 10 and 9ng/mL and limits of quantitation of 29 and 28ng/mL, for DOX and EPI, respectively. The method was successfully applied for the determination of DOX and EPI in biological fluids and in their commercial pharmaceutical preparations and the results were concordant with those obtained using a previously reported method. The application of the proposed method was extended to stability studies of DOX following different forced degradation conditions (acidic, alkaline, oxidative and photolytic) according to ICH guidelines. Moreover, the kinetics of the alkaline and oxidative degradation of DOX was investigated and the apparent first-order rate constants and half-life times were calculated.

Pharmacokinetics of doxorubicin in pregnant women.

PURPOSE: Our objective was to evaluate the pharmacokinetics (PK) of doxorubicin during pregnancy compared to previously published data from non-pregnant subjects. METHODS: During mid- to late-pregnancy, serial blood and urine samples were collected over 72 h from seven women treated with doxorubicin for malignancies. PK parameters were estimated using non-compartmental techniques. Pregnancy parameters were compared to those previously reported non-pregnant subjects. RESULTS: During pregnancy, mean (±SD) doxorubicin PK parameters utilizing 72 h sampling were: clearance (CL), 412 ± 80 mL/min/m(2); steady-state volume of distribution (Vss), 1,132 ± 476 L/m(2); and terminal half-life (T1/2), 40.3 ± 8.9 h. The BSA-adjusted CL was significantly decreased (p < 0.01) and T1/2 was not different compared to non-pregnant women. Truncating our data to 48 h, PK parameters were: CL, 499 ± 116 ml/min/m(2); Vss, 843 ± 391 L/m(2); and T1/2, 24.8 ± 5.9 h. The BSA-adjusted CL in pregnancy compared to non-pregnant data was significantly decreased in 2 of 3 non-pregnant studies (p < 0.05, < 0.05, NS). Vss and T1/2 were not significantly different. CONCLUSIONS: In pregnant subjects, we observed significantly lower doxorubicin CL in our 72 h and most of our 48 h sampling comparisons with previously reported non-pregnant subjects. However, the parameters were within the range previously reported in smaller studies. At this time, we cannot recommend alternate dosage strategies for pregnant women. Further research is needed to understand the mechanism of doxorubicin pharmacokinetic changes during pregnancy and optimize care for pregnant women.

In situ floating hydrogel for intravesical delivery of adriamycin without blocking urinary tract.

Drug solution is commonly used in conventional intravesical instillation. However, most of them would be easily eliminated by voiding, which significantly limit their efficacy. Recent advances in intravesical drug delivery are to use hydrogels as drug reservoir to extend the drug residence time in bladder. However, because of the high viscosity of hydrogel, urinary obstruction is usually existed during the intravesical instillation. To overcome these, we developed a floating hydrogel for the delivery of Adriamycin (ADR). The floating hydrogel was made of ADR, thermosensitive polymer (Poloxamer 407) and NaHCO3, which was liquid at low temperature, whereas formed gel at high temperature. In the presence of H⁺, NaHCO3 decomposed and produced CO2 that attached on the surface of hydrogel and helped the hydrogel float on the urine. Hence, the urinary tract will not be blocked. Meanwhile, the encapsulated ADR released in a controlled manner. These results suggest that the floating gel may have promising applications in intravesical therapy for bladder cancer.

Quantification of doxorubicin in biofluids using white light excitation fluorescence.

A fiber optic spectrometer setup was designed for white light excitation fluorescence 'WLEF' based measurements. Using this setup, two different analytical methods, a self referencing ratio-metric and a difference WLEF methods, were developed for the quantification of doxorubicin (DXR) in biofluids. It was seen that Acetonitrile (ACN) acts as an efficient and transparent extracting medium for DXR. The figures of merit and the percent recoveries of DXR in blood serum, even in presence of external fluorophores and in urine samples are comparable with existing analytical methods. The compact spectrometer is expected to be useful for easy quantification of fluorescent pharmaceuticals in biofluids.

Dual lifetime referenced fluorometry for the determination of doxorubicin in urine.

Dual lifetime referencing (DLR) is introduced as a rapid and self-referenced method for measuring the concentration of a fluorescent analyte in solution. The fluorescent cancer chemotherapeutic doxorubicin was chosen as a medically relevant analyte and blended with a reference dye (Ru(dpp)(3)) that displays overlapping excitation and emission spectra. The relative contributions of the short-lived (nanoseconds) fluorescent analyte and the long-lived (microseconds) reference dye define the observed lifetime. Measuring this lifetime by both frequency-domain DLR and time-domain DLR yields similar analytical ranges and limits of detection (0.4 µM). To assess the matrix effect of medical samples, the standard addition method was employed to both modes of DLR. Urine was spiked with doxorubicin and recovery rates of ≥97% were obtained.

Metabonomic study on the cumulative cardiotoxicity of a pirarubicin liposome powder.

Pirarubicin (THP) is an anthracycline frequently used in the chemotherapy against acute leukemia, malignant lymphoma and several solid tumors. However, its clinical use is severely limited by the development of a progressive dose-dependent cardiomyopathy that results in irreversible congestive heart failure. To provide a strategy for constraining or minimizing the cumulative cardiotoxicity of THP, a pirarubicin liposome powder (L-THP) was appropriately prepared, and the cumulative cardiotoxicity of L-THP and free THP (F-THP) were investigated on Sprague-Dawley rats after 3 successive doses. Urinary samples for metabonomic study, serum samples for biochemical assay, and heart samples for histopathology test were collected. As a result, the metabonomics-based findings such as PLS-DA plotting showed minimal metabolic alterations in L-THP as compared to F-THP, and correlated with the changes of serum biochemical assay and cardiac histopathology as measurements of damage to heart tissue. Our results confirm that when encapsulated into liposomes, the cumulative cardiotoxicity of THP can be greatly ameliorated. Lipophilic aglycone metabolites of THP associated with redox cycling are cardiotoxic for the possibility of reactive oxygen species (ROS) formation. Also, metabonomic analysis shows that the successive doses of THP will lead to severe metabolic pathways disturbances in the cell energy production. Further, the preliminary efficacy study of L-THP on lung cancer was evaluated in the approach of in vitro cytotoxicity on A549 cells by high content screening (HCS) analysis, and L-THP was found to exhibit better therapeutic index against lung cancer than THP.

Minor effects of the citrus flavonoids naringin, naringenin and quercetin, on the pharmacokinetics of doxorubicin in rats.

We investigated the effects of naringin, naringenin and quercetin on the pharmacokinetics of doxorubicin in rats. These Citrus flavonoids are known as P-glycoprotein (P-gp) inhibitors and thus suspected to interact with doxorubicin, as shown by in vitro cell studies. Plasma concentrations, tissue distribution, and the urinary and biliary excretion of doxorubicin after intravenous infusion were investigated in rats followed by oral administration of Citrus flavonoids. To evaluate the impact of the biotransformation of Citrus flavonoids on the P-gp inhibition, the inhibitory effects of quercetin and its metabolite on P-gp were compared using ex vivo analysis. Contrary to previous in vitro results, the plasma concentration, biliary and urinary clearance, and tissue distribution of doxorubicin were not altered by pre-treatment with naringin and naringenin. Biliary clearance and urinary clearance were slightly decreased by quercetin, but there was no statistical difference. The minor effects of these flavonoids may relate to their low systemic concentration, due to the biotransformation in vivo situation. S9 stability assay and calcein accumulation assay showed that quercetin was a metabolically unstable compound, and the inhibitory effect of its metabolites on P-gp was negligible. In conclusion, naringin, naringenin and quercetin did not affect the in vivo pharmacokinetics of intravenously administered doxorubicin.

Biological monitoring of nurses exposed to doxorubicin and epirubicin by a validated liquid chromatography/fluorescence detection method.

OBJECTIVES: Occupational exposure to antineoplastic drugs can represent a potential health risk for hospital staff. Assessing exposure is the first step in providing a safe work environment; the present study aimed to perform a biological monitoring (BM) of nurses exposed to doxorubicin and epirubicin. In order to assure data accuracy and reproducibility, the high-performance liquid chromatography with fluorescence detection method was validated. METHODS: Validation experiments were carried out according to the Food and Drug Administration guidelines. A detailed questionnaire about workplace practices and work organization was administered to 56 nurses of oncology department of two hospitals (A and B) located in southern Italy. End-shift urine samples were collected. Amounts of drugs handled were registered. RESULTS: The quantification and detection limits were 1.1 and 0.6 pg microl(-1) (doxorubicin) and 2.0 and 1.2 pg microl(-1) (epirubicin); moreover, the analytical method fulfilled all guidelines requirements. Questionnaire information evidenced that vertical laminar flow hoods were present in both hospitals, surfaces were cleaned with inappropriate detergents, no antispilling devices were adopted, and gloves were not changed during the work shift. A lower percentage of positive samples was found in the hospital where higher amounts of anthracyclines were handled (3.4% in A and 14.8% in B), suggesting individual incorrect working/cleaning practices in hospital A and overall hygienic standards to be improved in hospital B, where 'critical practices' were carried out. CONCLUSIONS: Results showed the crucial role of adopting effective safety precautions and handling practices to reduce exposure. Environmental and BM should be performed to discriminate between incorrect personal working modalities and general hygienic standards.

Determination of drug residues in urine of dogs receiving anti-cancer chemotherapy by liquid chromatography-electrospray ionization- tandem mass spectrometry: is there an environmental or occupational risk?

Cytotoxic drugs, previously used only in human medicine, are increasingly utilized for cancer treatment in veterinary practice. We developed and validated a liquid chromatography (LC)-electrospray ionization-tandem mass spectrometry (MS-MS) method to determine vincristine, vinblastine, cyclophosphamide, and doxorubicin in canine urine. Sample pretreatment consisted of liquid-liquid extraction, and LC separation was carried out on an RP C(18) column employing a 0.5% formic acid/methanol gradient system. The analytes were detected in positive ion mode using the MS-MS scan mode. The mean recoveries in six different urine samples were between 64.2% and 86.9%. Limits of quantitation were 0.5 microg/L for vincristine and vinblastine, 1 microg/L for cyclophosphamide, and 5 microg/L for doxorubicin; limits of detection were approximately 0.25 microg/L for vincristine, vinblastine, and cyclophosphamide and 0.5 microg/L for doxorubicin. It could be demonstrated that all investigated drugs are found in urine of dogs undergoing chemotherapy. In samples from day 1 after chemotherapy, as much as 63 microg/L vincristine, 111 microg/L vinblastine, and 762 microg/L doxorubicin could be detected. Cyclophosphamide showed only minor concentrations on day 1, but up to 2583 microg/L could be found directly after chemotherapy. These initial data show that there might be a potential contamination risk when administering cytotoxics in veterinary medicine.

Surveillance of workplace contamination and occupational exposure to antineoplastic agents in a hospital setting: establishment of a monitoring method using Doxorubicin.

An academic subcommittee of Japanese Society of Hospital Pharmacists formulated the guideline for the sterile preparation of antineoplastic agents in 2008. The practical methods to monitor a workplace contamination and occupational exposure to antineoplastic agents have not been introduced into a hospital setting yet. The aims of this study were to develop a monitoring method using doxorubicin for workplace contamination and occupational exposure to antineoplastic agents and to apply it to surveillance in a hospital setting. The surface contamination of workplace was wiped with non-woven fabric containing 70% 2-propanol. The occupational exposure was evaluated by spot urine sampling during 24 hours. Chromatographic separation was achieved by a reverse phase HPLC. Doxorubicin and fluorescein (internal standard) were detected at an excitation and emission wavelength of 470 and 550 nm, respectively. The monitoring method was applied to survey the workplace contamination and occupational exposure to antineoplastic agents in Hamamatsu University Hospital. The calibration curves for doxorubicin were linear over concentration ranges of 1.5-729 ng/100 cm(2) for surface contamination and 1.0-486 ng/ml for the urine. The run time was 10 min. The intra- and interassay precisions were within 8.5%. As the surveillance in a hospital setting, the flow line adhering to the guideline kept the exposure to low level. In addition, the occupational exposure in the workers was not observed. In conclusion, this study developed the monitoring method using doxorubicin for the workplace contamination and occupational exposure to antineoplastic agents. This method can be utilized to survey in a hospital setting.

Cytotoxic drug residues in urine of dogs receiving anticancer chemotherapy.

BACKGROUND: The presence of cytotoxic drug residues in urine of dogs may represent an exposure risk for pet owners and other people as well as a potential environmental contaminant. However, studies on cytotoxic drug residues in excretions of clinical patients are lacking in veterinary oncology. HYPOTHESIS: Variable concentrations of cytotoxic residues are present in urine samples, depending on sampling time and substance. ANIMALS: Client-owned dogs with lymphoma or mast cell tumors treated with standard chemotherapy protocols. METHODS: Urine samples were collected before, directly after, and on days after administration of chemotherapy. Measurement of vincristine, vinblastine, cyclophosphamide, and doxorubicin residues in canine urine was performed by a quantitative liquid chromatography tandem mass spectrometry (LC/MS/MS) method. RESULTS: Median cyclophosphamide residue concentration was 398.2 microg/L directly after treatment (d0) and was below the level of detection on days 1-3 (d1, d2, d3). Median vincristine residue concentration was 53.8 microg/L directly after treatment and was 20.2, 11.4, and 6.6 microg/L on days 1, 2, and 3. Median vinblastine residues were 144.9 (d0), 70.8 (d1), 35.6 (d2), and 18.7 microg/L (d3) with low concentrations detectable for 7 days after treatment. Median urine doxorubicin concentrations were 354.0 (d0), 165.6 (d1), 156.9 (d2), and 158.2 microg/L (d3). Low concentrations of doxorubicin were measurable up to 21 days after administration. CONCLUSIONS AND CLINICAL IMPORTANCE: Variable concentrations of chemotherapeutics were measured in urine samples, depending on sampling time point and drug. Findings may inform current chemoprotection guidelines and help minimize exposure risks.

Studying the interaction of pirarubicin with DNA and determining pirarubicin in human urine samples: combining excitation-emission fluorescence matrices with second-order calibration methods.

In this paper, UV-vis spectroscopy and fluorescence were combined to study the binding of Calf thymus DNA (ct-DNA) with the anthacycline antibiotic drug pirarubicin (THP). Ethidium bromide (EB) as the fluorescence probe was used to study the competitive binding interactions of THP with DNA by excitation-emission fluorescence matrices (EEFMs) coupled with the parallel factor analysis (PARAFAC) and the alternating normalization-weighted error algorithm (ANWE) with the second-order advantage. All the results conformed that THP mainly bound with DNA by intercalation. Meanwhile, the two second-order calibration methods have been successfully applied to quantify THP in urine samples. Figures of merit were applied to compare the performance of the two methods. The results presented in this work showed that both the PARAFAC and ANWE methods were the convincing way to be applied in the complex biological systems even in the presence of uncalibrated interferences.