Determination of doxorubicin and doxorubicinol in plasma of cancer patients by high-performance liquid chromatography

Protocol for long-term treatment of lowly aggressive cancer cell lines with low concentrations of anti-tumor drugs

The understanding of anti-tumor drug effects requires specific experimental settings which model clinical scenarios. We describe a protocol for 10-day treatment of lowly aggressive tumor cell lines with antineoplastic agents at concentrations which do not affect cell growth. We describe steps for seeding cells and treating cells with anti-tumor drugs. We then detail steps for cell sensitivity, cell proliferation, and mRNA and protein expression assays. We also detail assays to determine modifications in compound efflux. For complete details on the use and execution of this protocol, please refer to Rios Medrano et al.1.

Exposure to anticancer drugs modulates the expression of ACSL4 and ABCG2 proteins in adrenocortical carcinoma cells

Adrenocortical carcinoma (ACC) is a rare and malignant disease, with more than 50 % of patients developing hormone-secreting tumors. These tumors are genetically heterogeneous and potentially lethal, as metastasis is often underway at the time of diagnosis. While chemoresistance can be multifactorial, Acyl CoA synthetase 4 (ACSL4) is known to contribute to the generation of highly aggressive cellular phenotypes, while increased expression and activity of multidrug transporters such as ATP-binding cassette subfamily G member 2 (ABCG2) are known to play a key role. Therefore, the objective of this work was to determine changes in the expression of ACSL4 and ABCG2 in ACC cell lines after exposure to antitumor drugs. Bioinformatics analysis of public database GSE140818 revealed higher ACSL4 and ABCG2 expression in HAC15 cells resistant to mitotane when compared to wild type cells. In addition, our studies revealed an increase in ACSL4 and ABCG2 expression in lowly aggressive H295R cells undergoing early treatment with non-lethal concentrations of mitotane, doxorubicin and cisplatin. Comparable results were obtained in lowly aggressive breast cancer cells MCF-7. The increase in ACSL4 and ABCG2 expression favored tumor cell viability, proliferation and compound efflux, an effect partially offset by ACSL4 and ABCG2 inhibitors. These results provide relevant data on the undesired molecular effects of antitumor drugs and may fuel future studies on patients' early response to antitumor treatment.

Impact of single-nucleotide variants and nutritional status on population pharmacokinetics of Doxorubicin, and its effect on cardiotoxicity in children with leukemia

PURPOSE

 Doxorubicin is an important antineoplastic agent with wide interindividual variability in response to treatment and in its cardiotoxic effects. To determine the effect of genotypic status of three single-nucleotide variants in ABCC1, NCF4, and CBR3 genes and nutritional status assessed by body mass index, on the population pharmacokinetics of Doxorubicin and its cardiotoxic effects in pediatric patients with leukemia.

PATIENTS AND METHODS

Seventy pediatric patients treated with Doxorubicin were studied, in which 189 biological samples were obtained to determine Doxorubicin concentrations (1 to 3 samples per patient) at different times, for 20 h.

RESULTS

Low body mass index and age ≤ 7 years were associated with decreased clearance of Doxorubicin, and female gender was associated with increased clearance of Doxorubicin. Low BMI and low height were associated with a decrease and increase, respectively, in the intercompartmental clearance (Q) of Doxorubicin. TT homozygosity of the single-nucleotide variant rs3743527 of the ABCC1 gene was associated with an increase in clearance and decreased area under the curve, AA homozygosity of the single-nucleotide variant rs1883112 of the NCF4 gene was associated with a decrease in the volume of distribution in the peripheral compartment (V2), and GG homozygosity of CBR3 rs1056892 with increasing area under the curve.

CONCLUSION

Some covariates studied are directly related to the increase or decrease of the pharmacokinetic parameters of Doxorubicin. Decreased clearance, V2, and increased area under the curve were associated with systolic dysfunction, and decreased Q and V2 were associated with diastolic dysfunction. These results may contribute to the effective and safe use of Doxorubicin in pediatric patients with leukemia.

The effects of pazopanib on doxorubicin pharmacokinetics in children and adults with non-rhabdomyosarcoma soft tissue sarcoma: a report from Children's Oncology Group and NRG Oncology study ARST1321

PURPOSE

The use of tyrosine kinase inhibitors for the treatment for soft tissue sarcomas is increasing given promising signals of activity in a variety of tumor types. The recently completed study in non-rhabdomyosarcoma soft tissue sarcomas, ARST1321, demonstrated that the addition of pazopanib to neoadjuvant ifosfamide, doxorubicin, and radiation improved the pathological near complete response rate compared with chemoradiotherapy alone. Pharmacokinetic (PK) evaluation of doxorubicin with pazopanib has not been previously reported. As an exploratory aim, doxorubicin PK data were collected during the dose-finding phase of the study in patients receiving chemotherapy and pazopanib to assess the effect of pazopanib on doxorubicin PK parameters.

METHODS

Blood samples were collected during cycle 2 (week 4) of chemotherapy at the following time points from doxorubicin administration: predose, 5, 30, and 60 min, and 2, 4, 8, 24 ± 3, and 48 ± 3 h after dosing. The population pharmacokinetic and individual post hoc estimates of doxorubicin and doxorubicinol were determined by nonlinear mixed-effects modeling.

RESULTS

There were 52 doxorubicin and doxorubicinol samples from 7 individuals in this study (median age: 17 years; range 14-23). The doxorubicin clearance was 26.9 (16.1, 36.4, and 33.9) L/h/m2 (post hoc median and range) and 25.8 (23.3%) L/h/m2 [population estimate and IIV (CV%)]. The doxorubicinol apparent clearance was 67.5 (18.2, 1701) L/h/m2 (post hoc median and range) and 58.7 (63.7%) L/h/m2 [population estimate and IIV (CV%)].

CONCLUSION

The PK data of seven patients treated on ARST1321 is consistent with previously reported population and post hoc doxorubicin clearance and doxorubicinol apparent clearance estimates, showing that the addition of pazopanib does not significantly alter doxorubicin pharmacokinetics. These data support the safety of administration of pazopanib with doxorubicin-containing chemotherapy.

Application of Optical Methods for Determination of Concentration of Doxorubicin in Blood and Plasma

The aim of presented research is to develop a simple and quick method of spectrophotometric detection for the determination of doxorubicin hydrochloride in blood and plasma. Anthracycline antibiotics are among the most effective antineoplastic agents. However, despite their high efficacy in the treatment of various types of cancer, their administration is limited primarily because they exhibit myocardial toxicity. This may be a limiting factor in the dosage of medications; nevertheless, drugs exhibiting this mechanism of action constitute a very important group of chemotherapeutics. One of the more widely studied antibiotics from the anthracycline group is doxorubicin. It exhibits the highest antineoplastic activity from among a number of derivative compounds. Because of the adverse effects of doxorubicin, especially cardiotoxicity, it is important to maintain control of its concentration in body fluids. The method in the study consists of extraction doxorubicin from the plasma or blood and measurements of the absorbance of light in the visible light range in a DOX solution with respect to a reference sample. The research used blood and plasma samples spiked with doxorubicin to give concentrations in the range of 0.2–10 µg/mL. Obtained LODs were 1.6 µg/mL and 1.2 µg/mL, respectively.

Dantrolene Prevents the Lymphostasis Caused by Doxorubicin in the Rat Mesenteric Circulation

Background and Purpose: Doxorubicin (DOX) is a risk factor for arm lymphedema in breast cancer patients. We reported that DOX opens ryanodine receptors (RYRs) to enact "calcium leak," which disrupts the rhythmic contractions of lymph vessels (LVs) to attenuate lymph flow. Here, we evaluated whether dantrolene, a clinically available RYR1 subtype antagonist, prevents the detrimental effects of DOX on lymphatic function. Experimental Approach: Isolated rat mesenteric LVs were cannulated, pressurized (4-5 mm Hg) and equilibrated in physiological salt solution and Fura-2AM. Video microscopy recorded changes in diameter and Fura-2AM fluorescence tracked cytosolic free calcium ([Ca2+ i]). High-speed in vivo microscopy assessed mesenteric lymph flow in anesthetized rats. Flow cytometry evaluated RYR1 expression in freshly isolated mesenteric lymphatic muscle cells (LMCs). Key Results: DOX (10 μmol/L) increased resting [Ca2+ i] by 17.5 ± 3.7% in isolated LVs (n = 11). The rise in [Ca2+ i] was prevented by dantrolene (3 μmol/L; n = 10). A single rapid infusion of DOX (10 mg/kg i.v.) reduced positive volumetric lymph flow to 29.7 ± 10.8% (n = 7) of baseline in mesenteric LVs in vivo. In contrast, flow in LVs superfused with dantrolene (10 μmol/L) only decreased to 76.3 ± 14.0% (n = 7) of baseline in response to DOX infusion. Subsequently, expression of the RYR1 subtype protein as the presumed dantrolene binding site was confirm in isolated mesenteric LMCs by flow cytometry. Conclusion and Implications: We conclude that dantrolene attenuates the acute impairment of lymph flow by DOX and suggest that its prophylactic use in patients subjected to DOX chemotherapy may lower lymphedema risk.

Doxorubicin Activates Ryanodine Receptors in Rat Lymphatic Muscle Cells to Attenuate Rhythmic Contractions and Lymph Flow

Doxorubicin is a risk factor for secondary lymphedema in cancer patients exposed to surgery or radiation. The risk is presumed to relate to its cytotoxicity. However, the present study provides initial evidence that doxorubicin directly inhibits lymph flow and this action appears distinct from its cytotoxic activity. We used real-time edge detection to track diameter changes in isolated rat mesenteric lymph vessels. Doxorubicin (0.5-20 μmol/l) progressively constricted lymph vessels and inhibited rhythmic contractions, reducing flow to 24.2% ± 7.7% of baseline. The inhibition of rhythmic contractions by doxorubicin paralleled a tonic rise in cytosolic Ca²⁺ concentration in lymphatic muscle cells, which was prevented by pharmacological antagonism of ryanodine receptors. Washout of doxorubicin partially restored lymph vessel contractions, implying a pharmacological effect. Subsequently, high-speed optical imaging was used to assess the effect of doxorubicin on rat mesenteric lymph flow in vivo. Superfusion of doxorubicin (0.05-10 μmol/l) maximally reduced volumetric lymph flow to 34% ± 11.6% of baseline. Likewise, doxorubicin (10 mg/kg) administered intravenously to establish clinically achievable plasma concentrations also maximally reduced volumetric lymph flow to 40.3% ± 6.0% of initial values. Our findings reveal that doxorubicin at plasma concentrations achieved during chemotherapy opens ryanodine receptors to induce "calcium leak" from the sarcoplasmic reticulum in lymphatic muscle cells and reduces lymph flow, an event linked to lymph vessel damage and the development of lymphedema. These results infer that pharmacological block of ryanodine receptors in lymphatic smooth muscle cells may mitigate secondary lymphedema in cancer patients subjected to doxorubicin chemotherapy. SIGNIFICANCE STATEMENT: Doxorubicin directly inhibits the rhythmic contractions of collecting lymph vessels and reduces lymph flow as a possible mechanism of secondary lymphedema, which is associated with the administration of anthracycline-based chemotherapy. The inhibitory effects of doxorubicin on rhythmic contractions and flow in isolated lymph vessels were prevented by pharmacological block of ryanodine receptors, thereby identifying the ryanodine receptor family of proteins as potential therapeutic targets for the development of new antilymphedema medications.

Reversing the undesirable pH-profile of doxorubicin via activation of a di-substituted maleamic acid prodrug at tumor acidity

Selective drug release at pH 6.7 over pH 7.4 is achieved through a combination of ‘switch-on’ and ‘switch-off’ mechanisms.

Multi-channel cell co-culture for drug development based on glass microfluidic chip-mass spectrometry coupled platform

RATIONALE

Cell-based drug assay plays an essential role in drug development. By coupling a microfluidic chip with mass spectrometry (MS), we developed a multifunctional platform. Cell co-culture, cell apoptosis assay, fluorescence and MS detection of intracellular drug absorption could be simultaneously conducted on this platform.

METHODS

Three micro-channels were fabricated through photolithography technology to conduct the cell co-culture. Cell apoptosis after drug treatment was assayed by fluorescent probes (Hoechst 33342). Intracellular Dox absorption was analyzed by confocal fluorescent microscopy. With a high voltage (~ 4.5 kV) applied onto the microfluidic chip, the ionization spray was successfully generated by dropping isopropanol onto it. By coupling with a Shimadzu LCMS-2010 A mass spectrometer, intracellular CPA absorption was detected on the microfluidic chip.

RESULTS

The microfluidic chip-MS coupled platform showed high biocompatibility. Distinction of cell apoptosis between co-cultured and mono-cultured cells was detected. The results of intracellular drug absorption well explained the different cell apoptosis rate.

CONCLUSIONS

Cell-based drug assay was facilely and successfully conducted on the microfluidic chip-MS coupled platform. This technology we have devised could promote MS application in the field of drug development. Copyright © 2016 John Wiley & Sons, Ltd.

The human organic cation transporter OCT1 mediates high affinity uptake of the anticancer drug daunorubicin

Anthracyclines such as daunorubicin are anticancer agents that are transported into cells, and exert cytotoxicity by blocking DNA metabolism. Although there is evidence for active uptake of anthracyclines into cells, the specific transporter involved in this process has not been identified. Using the high-grade serous ovarian cancer cell line TOV2223G, we show that OCT1 mediated the high affinity (K_m ~ 5 μM) uptake of daunorubicin into the cells, and that micromolar amounts of choline completely abolished the drug entry. OCT1 downregulation by shRNA impaired daunorubicin uptake into the TOV2223G cells, and these cells were significantly more resistant to the drug in comparison to the control shRNA. Transfection of HEK293T cells, which accommodated the ectopic expression of OCT1, with a plasmid expressing OCT1-EYFP showed that the transporter was predominantly localized to the plasma membrane. These transfected cells exhibited an increase in the uptake of daunorubicin in comparison to control cells transfected with an empty EYFP vector. Furthermore, a variant of OCT1, OCT1-D474C-EYFP, failed to enhance daunorubicin uptake. This is the first report demonstrating that human OCT1 is involved in the high affinity transport of anthracyclines. We postulate that OCT1 defects may contribute to the resistance of cancer cells treated with anthracyclines.

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.

Monitoring subcellular biotransformation of N-L-leucyldoxorubicin by micellar electrokinetic capillary chromatography coupled to laser-induced fluorescence detection

Development of prodrugs is a promising alternative to address cytotoxicity and nonspecificity of common anticancer agents. N-L-leucyldoxorubicin (LeuDox) is a prodrug that is biotransformed to the anticancer drug doxorubicin (Dox) in the extracellular space; however, its biotransformation may also occur intracellularly in endocytic organelles. Such organelle-specific biotransformation is yet to be determined. In this study, magnetically enriched endocytic organelle fractions from human uterine sarcoma cells were treated with LeuDox. Micellar electrokinetic chromatography with laser-induced fluorescence detection (MEKC-LIF) was used to determine that 10% of LeuDox was biotransformed to Dox, accounting for ~43% of the biotransformation occurring in the post-nuclear fraction. This finding suggests that endocytic organelles also participate in the intracellular biotransformation of LeuDox to Dox.

Microspheres targeted with a mesothelin antibody and loaded with doxorubicin reduce tumor volume of human mesotheliomas in xenografts

Background

Malignant mesotheliomas (MMs) are chemoresistant tumors related to exposure to asbestos fibers. The long latency period of MM (30-40 yrs) and heterogeneity of tumor presentation make MM difficult to diagnose and treat at early stages. Currently approved second-line treatments following surgical resection of MMs include a combination of cisplatin or carboplatin (delivered systemically) and pemetrexed, a folate inhibitor, with or without subsequent radiation. The systemic toxicities of these treatments emphasize the need for more effective, localized treatment regimens.

Methods

Acid-prepared mesoporous silica (APMS) microparticles were loaded with doxorubicin (DOX) and modified externally with a mesothelin (MB) specific antibody before repeated intraperitoneal (IP) injections into a mouse xenograft model of human peritoneal MM. The health/weight of mice, tumor volume/weight, tumor necrosis and cell proliferation were evaluated in tumor-bearing mice receiving saline, DOX high (0.2 mg/kg), DOX low (0.05 mg/kg), APMS-MB, or APMS-MB-DOX (0.05 mg/kg) in saline.

Results

Targeted therapy (APMS-MB-DOX at 0.05 mg/kg) was more effective than DOX low (0.05 mg/kg) and less toxic than treatment with DOX high (0.2 mg/kg). It also resulted in the reduction of tumor volume without loss of animal health and weight, and significantly decreased tumor cell proliferation. High pressure liquid chromatography (HPLC) of tumor tissue confirmed that APMS-MB-DOX particles delivered DOX to target tissue.

Conclusions

Data suggest that targeted therapy results in greater chemotherapeutic efficacy with fewer adverse side effects than administration of DOX alone. Targeted microparticles are an attractive option for localized drug delivery.

A mechanistic study of the effect of doxorubicin/adriamycin on the estrogen response in a breast cancer model

OBJECTIVE

Estrogen treatment limits the cytotoxic effects of chemotherapy in estrogen receptor-positive (ER+) breast cancer cell lines, suggesting that estrogen pathway signaling may confer chemotherapeutic resistance. This study investigates the molecular responses of ER+ breast cancer cell lines to the chemotherapeutic agent, doxorubicin, in the presence or absence of estrogen.

METHODS

ER+ MCF-7 and T47-D cells were cultured in hormone-starved or estrogen-containing media with or without doxorubicin at concentrations mimicking the low concentrations seen in plasma and tumor microenvironments in humans following typical bolus administration. Protein levels, phosphorylations, and interactions of estrogen-signaling molecules were assessed following these treatments, as well the effects of ER signaling inhibitors on cell proliferation.

RESULTS

Surprisingly, estrogen and doxorubicin co-treatment markedly induced pro-growth alterations compared to doxorubicin alone and modestly enhanced estrogen alone-induced changes. Several inhibitors suppressed cell proliferation in the presence of doxorubicin and estrogen.

CONCLUSIONS

These findings demonstrate that molecular changes caused by doxorubicin in ER+ breast cancer cells can be reversed by estrogen, providing molecular evidence for the poorer responses of ER+ tumors to doxorubicin in the presence of physiologic estrogen levels. Our results also suggest that the addition of drugs targeting the ER, EGFR, the SFKs, MEK, PI3K, and/or the MMP proteins to a conventional chemotherapy regimen may improve chemosensitivity.

Quantitative liquid chromatographic analysis of anthracyclines in biological fluids

Anthracyclines are amongst the most widely used drugs in oncology, being part of the treatment regimen in most patients receiving systemic chemotherapy. This review provides a comprehensive summary of the sample preparation techniques and chromatographic methods that have been developed during the last two decades for the analysis of the 4 most administered anthracyclines, doxorubicin, epirubicin, daunorubicin and idarubicin in plasma, serum, saliva or urine, within the context of clinical and pharmacokinetic studies or for assessing occupational exposure. Following deproteinization, liquid-liquid extraction, solid phase extraction or a combination of these techniques, the vast majority of methods utilizes reversed-phase C18 stationary phases for liquid chromatographic separation, followed by fluorescence detection, or, more recently, tandem mass spectrometric detection. Some pros and cons of the different techniques are addressed, in addition to potential pitfalls that may be encountered in the analysis of this class of compounds.

Increased efficacy of doxorubicin delivered in multifunctional microparticles for mesothelioma therapy

New and effective treatment strategies are desperately needed for malignant mesothelioma (MM), an aggressive cancer with a poor prognosis. We have shown previously that acid-prepared mesoporous microspheres (APMS) are nontoxic after intrapleural or intraperitoneal (IP) administration to rodents. The purpose here was to evaluate the utility of APMS in delivering chemotherapeutic drugs to human MM cells in vitro and in two mouse xenograft models of MM. Uptake and release of doxorubicin (DOX) alone or loaded in APMS (APMS-DOX) were evaluated in MM cells. MM cell death and gene expression linked to DNA damage/repair were also measured in vitro. In two severe combined immunodeficient mouse xenograft models, mice received saline, APMS, DOX or APMS-DOX injected directly into subcutaneous (SC) MM tumors or injected IP after development of human MMs peritoneally. Other mice received DOX intravenously (IV) via tail vein injections. In comparison to DOX alone, APMS-DOX enhanced intracellular uptake of DOX, MM death and expression of GADD34 and TP73. In the SC MM model, 3× weekly SC injections of APMS-DOX or DOX alone significantly inhibited tumor volumes, and systemic DOX administration was lethal. In mice developing IP MMs, significant (p < 0.05) inhibition of mesenteric tumor numbers, weight and volume was achieved using IP administration of APMS-DOX at one-third the DOX concentration required after IP injections of DOX alone. These results suggest APMS are efficacious for the localized delivery of lower effective DOX concentrations in MM and represent a novel means of treating intracavitary tumors.

Pharmacokinetic evaluation of doxorubicin plasma levels in normal and overweight patients with breast cancer and simulation of dose adjustment by different indexes of body mass

Although being used for decades in the treatment of several types of cancer, either alone or in association, only a few data about the pharmacokinetics of doxorubicin (DOX) in humans are available. DOX is frequently used in association with other anticancer drugs in the management of breast cancer. Pharmacokinetic data available in the literature show that after i.v. administration DOX follows a two-compartment open model, with a fast distribution phase followed by a very slow elimination phase. The objective of this work is to perform a pilot study in order to verify if the usual dose adjustment based on body surface area (BSA) would be producing the same plasma concentration-time profiles in patients with normal (<25) and above normal (>25) body mass index (BMI). In order to assess the pharmacokinetics of DOX after a short-term i.v. infusion of 60mg/m(2) of BSA, an experimental design using only five plasma samples of each patient was applied. Samples were collected at 0.00, 0.66 (right after the end of infusion), 1.66, 8.66, and 24.66h. DOX pharmacokinetic profiles were evaluated after quantification of DOX using a new HPLC method developed and validated. Pharmacokinetic parameters (AUC(0-24.66) and C(max)) were analyzed by non-compartmental and compartmental approaches. Significant differences (α=0.05) between overweight and normal weight groups were found with respect to AUC and C(max). After adjustment of dose by weight and by BMI, the compartmental model was used to simulate plasma concentrations and new values for C(max) and AUC(0-24.66) were calculated. The new values obtained using both body weight (BW) and BMI were closer to the normal group than those obtained with BSA. According to the simulation, the differences of AUC and C(max) between the overweight group and the group of patients with normal weight were lower when the dose was adjusted by BW and BMI. These results suggest that more studies must be conducted, with more patients, in order to evaluate the best dose adjustment for DOX in women with breast cancer and overweight.

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.

Validation of an LC-MS/MS method for the determination of epirubicin in human serum of patients undergoing drug eluting microsphere-transarterial chemoembolization (DEM-TACE)

Drug Eluting Microsphere-Transarterial Chemoembolization (DEM-TACE) is a new delivery system to administrate drugs in a controlled manner useful for application in the chemoembolization of colorectal cancer metastases to the liver. DEM-TACE is focused to obtain higher concentrations of the drug to the tumor with lower systemic concentrations than traditional cancer chemotherapy. Therefore a specific, precise and sensitive LC-ESI-MS/MS assay procedure was properly designed to detect and quantify epirubicin at the concentrations expected from a transarterial chemoembolization with microspheres. Serum samples were kept acidic (pH approximately of 3.5) and sample preparation consisted of a solid phase extraction (SPE) procedure with HLB OASIS cartridges using a methylene chloride/2-propanol/methanol mixture solution to recover epirubicin. The analyses consisted of reversed-phase high-performance liquid chromatography (rp-HPLC) coupled with tandem mass spectrometry (MS/MS). Accuracy, precision and matrix effect of this procedure were carried out by analyzing four quality control samples (QCs) on five separate days. The validation parameters were assessed by recovery studies of spiked serum samples. Recoveries were found to vary between 92 and 98% at the QC levels (5, 40, 80 and 150 microg/L) with relative standard deviation (RSD) always less than 3.7%. The limit of detection (LOD) was set at 1 microg/L. The developed procedure has been also applied to investigate the different capability of two types of commercially available microspheres to release epirubicin into the human circulatory system.

A simple HPLC method for doxorubicin in plasma and tissues of nude mice

Doxorubicin is a cytotoxic anthracycline that has been used for the treatment of several malignancies. Several HPLC methods have been reported for the quantification of doxorubicin in biological samples. Tissue matrix effect and sample size requirements, however, have been remaining issues for simple and easy-to-adapt analytical methods in small animal experiments. The present study established a simple HPLC method for doxorubicin in plasma and tissues (tumor, heart, spleen, liver, gastrointestinal tract, brain, lung, and kidney) of nude mice. Our method required a small sample volume (100 microL plasma and 10 mg tissue), which made it possible to use each blank tissue for calibration curves. The limit of quantification was 25 ng/mL in plasma and 0.1 to 0.4 microg/mg in other tissues with recovery rates ranging from 52.4 to 95.2%. The linearity, accuracy and precision in all tissues, except gastrointestinal tract (GIT), were found to be acceptable in the range of 25-2000 ng/mL plasma and 0.1-4 ng/mg tissue. This method was used successfully to determine the drug concentration in plasma and tissues of human tumor xenograft-bearing nude mice given intratumoral doxorubicin in a polymeric drug delivery system designed for sustained release. In conclusion, the present method may be useful as a simple and easy-to-adapt, yet, sensitive analytical method of doxorubicin for plasma and tissue pharmacokinetic studies in small animals such as nude mice.

Evaluation of Alternate Size Descriptors for Dose Calculation of Anticancer Drugs in the Obese

Purpose

Despite the rising prevalence of obesity, there is paucity of information describing how doses of anticancer drugs should be adjusted in clinical practice. Here, we assessed the pharmacokinetics of eight anticancer drugs in adults and evaluated the potential utility of alternative weight descriptors in dose calculation for the obese.

Patients and Methods

A total of 1,206 adult cancer patients were studied, of whom 162 (13.4%) were obese (body mass index ≥ 30). Pharmacokinetic parameters were calculated using noncompartmental analysis, and compared between lean (body mass index ≤ 25) and obese patients.

Results

The absolute clearance of cisplatin, paclitaxel, and troxacitabine was significantly increased in the obese (P < .023), but this was not observed for carboplatin, docetaxel, irinotecan, or topotecan (P < .17). For doxorubicin, the systemic clearance was statistically significantly reduced in obese women (P = .013), but not in obese men (P = .52). Evaluation of alternate weight descriptors for dose calculation in the obese, including predicted normal weight, lean body mass, (adjusted) ideal body weight, and the mean of ideal and actual body weight, indicated that, for most of the evaluated drugs, weight scalars used to calculate body-surface area should consider actual body weight regardless of size.

Conclusion

The results suggest that a number of widely used empiric strategies for dose adjustments in obese patients, including a priori dose reduction or dose capping, should be discouraged.

Chemoembolization of hepatocellular carcinoma with drug eluting beads: efficacy and doxorubicin pharmacokinetics

BACKGROUND/AIMS

This study assesses the safety, pharmacokinetics and efficacy of transarterial chemoembolization using drug eluting beads (DEB), an embolizing device that slowly releases chemotherapy to decrease systemic toxicity.

METHODS

Twenty-seven Child-Pugh A cirrhotics (76% male, 59% HCV) with untreated large/multifocal HCC received chemoembolization with doxorubicin loaded DEBs at doses adjusted for bilirubin and body surface (range: 47-150 mg). Clinical and analytical data were recorded at 24 and 48 h, 7, 14 and 30 days after first and second TACE. Response rate was assessed by CT at 6 months. Blood samples were obtained in 13 patients at 5, 20, 40, 60, 120 min, 6, 24, 48 and 168 h to determine doxorubicin Cmax and AUC.

RESULTS

DEB-TACE was well tolerated with an acceptable safety profile. Two cases developed liver abscess, one leading to death. Response rate was 75% (66.6% on intention-to-treat). Doxorubicin Cmax and AUC were significantly lower in DEB-TACE patients (78.97+/-38.3 ng/mL and 662.6+/-417.6 ng/mLmin) than in conventional TACE (2341.5+/-3951.9 ng/mL and 1812.2+/-1093.7 ng/mLmin, p=0.00002 and p=0.001, respectively). After a median follow-up of 27.6 months, 1- and 2-year survival is 92.5% and 88.9%, respectively.

CONCLUSIONS

Chemoembolization using DEBs is an effective procedure with a favorable pharmacokinetic profile.

Rapid high throughput assay for fluorimetric detection of doxorubicin--application of nucleic acid-dye bioprobe

A double stranded DNA based fluorescence bioprobe for anticancer agent (doxorubicin) detection is described. This method provides a new way for sensitive DNA/drug interaction study by a homogeneous assay. The probe employs the long-wavelength intercalating fluorophore TOTO-3 (TT3). The anticancer agent, doxorubicin, which interacts with the DNA-TT3 complex, was indirectly measured by the decrease in the fluorescence intensity. Various oligonucleotides with different sequences were examined. Doxorubicin has preference for the oligonucleotide 5'AGCACG3'. Enhanced fluorescence observed for the TT3 intercalation with this oligonucleotide makes the DNA-dye complex a suitable bioprobe for doxorubicin detection by competitive assay. A home-built CCD camera setup was applied along with 384 well plate assay format for high throughput fluorescence imaging. The detection limit can be as low as 25 ng mL(-1) with an upper limit of 100 microg mL(-1). The recovery test with spiked serum sample shows that this method can be a potential routine method for therapeutic drug monitoring (TDM).

Separation of doxorubicin and doxorubicinol by cyclodextrin-modified micellar electrokinetic capillary chromatography

Doxorubicinol (DOXol) is a human metabolite of the chemotherapy agent doxorubicin (DOX), and is associated with dose-dependent cardiotoxicity and decreased drug efficacy. Due to the structural similarities and equal molecular charges of DOXol and DOX, their electrophoretic separation is commonly ineffective. A method for separating and detecting DOX and DOXol, as well as two DOXol enantiomers, was established using cyclodextrin-modified micellar electrokinetic capillary chromatography with laser-induced fluorescence detection. Differential DOXol production was detected in a DOX-sensitive and resistant pair of cell lines, with a 0.08 +/- 0.01 fmol limit of detection.

Spectrophotometric Determination of Anthracycline Anticancer Agents with Aluminum(III) and Chromazurol S in a Nonionic Surfactant Micellar Medium

A simple and highly sensitive spectrophotometric method for the determination of anthracycline anticancer agents, such as Daunorubicin hydrochloride (DAU), was established by using aluminum(III) and Chromazurol S (CAS) in a nonionic surfactant micellar medium. In the case of determination of DAU, the apparent molar absorptivity was 1.3 x 10(5) dm3 mol(-1) cm(-1) at 615 nm. Beer's law was obeyed in the concentration range of 0.028 - 2.82 microg ml(-1) for DAU. Owing to no need for solvent extraction, this method could be applied to assays of DAU and related drugs in pharmaceutical preparations.

Accelerator mass spectrometry allows for cellular quantification of doxorubicin at femtomolar concentrations

Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as (14)C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining total cellular [(14)C]anthracycline concentrations following administration of doxorubicin (DOX) and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of [(14)C]anthracycline at the tumor level. In order to validate the sensitivity of AMS versus HPLC with fluorescence detection, we performed three studies comparing the cellular accumulation of DOX: one in vitro cell line study, and two in vivo xenograft mouse studies. Using AMS, we quantified cellular [(14)C]anthracycline content up to 4 h following in vitro exposure at concentrations ranging from 0.2 pg/ml (345 fM) to 2 microg/ml (3.45 microM) [(14)C]DOX. The results of this study show that, compared to standard fluorescence-based HPLC, the AMS method was over five orders of magnitude more sensitive. Two in vivo studies compared the sensitivity of AMS to HPLC using a nude mouse xenograft model in which breast cancer cells were implanted subcutaneously. After sufficiently large tumors formed, [(14)C]DOX was administered intravenously at two dose levels. Additionally, we tested the AMS method in a nude mouse xenograft model of multidrug resistance (MDR) in which each mouse was implanted with both wild type and MDR+ cells on opposite flanks. The results of the second and third studies showed that [(14)C]anthracycline concentrations were significantly higher in the wild type tumors compared to the MDR+ tumors, consistent with the MDR model. Although this method does not discriminate between parent drug and metabolites, the extreme sensitivity of AMS should facilitate similar studies in humans to establish target site drug delivery and to potentially determine the optimal treatment dose and regimen.

The effect of granisetron on in vitro metabolism of doxorubicin, irinotecan and etoposide

OBJECTIVE

Doxorubicin, irinotecan and etoposide are all associated with the debilitating side-effects of nausea and vomiting, thereby necessitating concomitant antiemetic therapy. However, this may increase the potential for drug-drug interactions by inhibition or induction of the cytochrome P450 enzymes. A study was undertaken to investigate the effects of the 5-HT(3) -receptor antagonist granisetron on the metabolism of doxorubicin, irinotecan and etoposide in vitro in human liver microsomal preparations.

RESEARCH DESIGN AND METHODS

Doxorubicin, 20 microM, irinotecan, 10 microM, and etoposide, 50 microM, were incubated in the presence of granisetron, 0 nM, 20 nM, 200 nM and 2000 nM, in human liver microsomal preparations (250 microg). The levels of unchanged doxorubicin, irinotecan and etoposide in the incubation mixture were determined by high-performance liquid chromatography. Positive controls were ketoconazole, 20 microM, a potent inhibitor of CYP3A metabolism, for irinotecan and etoposide and quercitrin, 2 mM, a potent inhibitor of aldo-keto reductase, for doxorubicin.

RESULTS

In the absence of granisetron, unchanged doxorubicin, irinotecan and etoposide levels decreased by 34.2 +/- 5.5%, 21.3 +/- 2.9% and 13.4 +/- 1.6% of control, respectively. Ketoconazole prevented the breakdown of both irinotecan and etoposide, while quercitrin inhibited the breakdown of doxorubicin. Granisetron had no effect on the rate of reduction of doxorubicin, irinotecan or etoposide.

CONCLUSIONS

The results from this study suggest that granisetron neither inhibits nor induces the enzymes involved in the metabolism of doxorubicin, irinotecan or etoposide. Thus, granisetron can be used safely to treat nausea and vomiting induced by these agents with minimal risk of drug-drug interactions.

Quantification of Doxorubicin and metabolites in rat plasma and small volume tissue samples by liquid chromatography/electrospray tandem mass spectroscopy

The anthracycline Doxorubicin (DXR) is used widely for the treatment of human malignancies, and drug delivery technologies are under investigation to enhance antitumor selectivity and effectiveness. A liquid chromatography-tandem mass spectroscopy (LC-MS/MS) method was developed to identify and quantify DXR and key metabolites in small-volume biological samples. The assay was linear over the therapeutically relevant concentration range (0.125-10,000 nM); in brain tissue, the lower limit of quantification was 0.247 nM and the sensitivity was 1.4 pg. The ability to quantify DXR and detect metabolite formation may provide insight into the toxicity and bioavailability of drug incorporated into carriers such as liposomes.

A phase I and pharmacologic study of the MDR converter GF120918 in combination with doxorubicin in patients with advanced solid tumors

BACKGROUND

Resistance to chemotherapy can partly be explained by the activity of membrane bound P-glycoprotein. Competitive inhibition of P-glycoprotein, by multidrug resistance (MDR) converters, may overcome this MDR. Previously studied MDR converters either have serious intrinsic side effects or considerably influence the pharmacokinetics of cytotoxic agents at concentrations theoretically required to convert MDR. GF120918 is a third-generation MDR converter with high affinity for P-glycoprotein and can be given orally. We performed a phase 1 study with escalating doses of GF120918 in combination with doxorubicin.

PATIENTS AND METHODS

The study group comprised 46 patients with advanced solid tumors. Doxorubicin was administered on day 1 (cycle 1), GF120918 on days 22-24 (cycle 2), and on days 29-33 with doxorubicin administered on day 31 (cycle 3). Pharmacokinetics of both GF120918 and doxorubicin were studied. The starting daily dose of GF120918 was 50 mg and was to be increased in subsequent cohorts until a steady state plasma level of 100 ng/ml was reached. The starting dose of doxorubicin was 50 mg/m2 and was to be increased after reaching the target dose level of GF120918.

RESULTS

In 37 of the 46 patients, full pharmacokinetic data from the three scheduled cycles were obtained. Pharmacokinetics of GF120918 showed a less than linear increase in Cmax with increasing doses, with considerable interpatient variation. The target steady-state plasma level for GF120918 was exceeded in 12 out of 19 patients who received 400 mg GF120918 alone twice daily and in 12 of 17 patients who received 400 mg GF120918 twice daily in combination with doxorubicin. GF120918 pharmacokinetics were not influenced by coadministration of doxorubicin. The doxorubicin AUC was only marginally influenced by GF120918 and only at the highest dose levels. In these patients there was a significant increase in the AUC of doxorubicinol in cycle 3 as compared to cycle 1. Hematologic toxicity mainly consisted of neutropenia and was more severe in cycle 3 than in cycle 1 (13 vs 5 patients with grade 4 neutropenia, P=0.003). Neutropenic fever was the dose-limiting toxicity at a doxorubicin dose of 75 mg/m2 with 400 mg GF120918 twice daily. The toxicity of GF120918 was limited to somnolence in eight patients and occasional gastrointestinal complaints.

CONCLUSION

GF120918 is an MDR converter with only minimal side effects at a dose level yielding concentrations able to convert the action of P-glycoprotein in vitro. A doxorubicin dose of 60 mg/m2 on day 3 in combination with 400 mg GF120918 twice daily on days 1-5 is an acceptable regimen for further clinical trials.

Factors affecting pharmacokinetic variability following doxorubicin and docetaxel-based therapy

Current dosing strategies for anticancer drugs result in wide interindividual pharmacokinetic variability. Here, we explored the influence of age, body size, concomitant drugs, dose, infusion duration, and sex on the clearance for doxorubicin and docetaxel in 243 individual patients. Patients received doxorubicin (n=110) or docetaxel (n=152) as monotherapy or in combination chemotherapy regimens. The mean (+/-S.D.) clearance was 63.6+/-22.7 L/h for doxorubicin and 42.8+/-14.9 L/h for docetaxel. Normalisation for body surface area (BSA) reduced the interindividual variability by only <1.7%. Doxorubicin clearance was significantly reduced when administered at doses >50 mg/m(2) or in combination with cyclophosphamide. Upper extremes of body size were associated with increased clearance for both drugs, whereas no consistent effect of age on clearance was discerned. Overall, these findings suggest that incorporation of variables in addition to BSA should be considered in routine dosing strategies for doxorubicin and docetaxel.

Trace determination of anthracyclines in urine: a new high-performance liquid chromatography/tandem mass spectrometry method for assessing exposure of hospital personnel

Health-care workers handling antineoplastic agents may be exposed to extremely low doses of these drugs. Very sensitive and specific analytical methods are therefore needed for biological monitoring. The aim of this study was to develop and validate a method for trace level determination of doxorubicin, epirubicin, daunorubicin and idarubicin in human urine, using epi-daunorubicin as an internal standard. Solid-phase extraction (SPE) was used for sample preparation. Urine samples were loaded onto Bond Elut C18 cartridges. The analytes were eluted in methylene chloride/2-propanol (1:1, v/v) and then evaporated to dryness. The residue was reconstituted with the mobile phase prior to high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) analysis. Quantitation of each analyte was performed using the multiple reaction monitoring (MRM) method. The urine assay was linear over the range 0.1-2.0 microg/L, with a lower limit of quantification (LLOQ) of 0.10 microg/L for doxorubicin and epirubicin, and 0.03 microg/L for daunorubicin and idarubicin. The respective limits of detection (LODs) were 0.04 and 0.01 microg/L. The precision and accuracy of the assay were determined on three different days. The within-series precision was found to be always less than 13.9% for all the analytes. The overall precision expressed as relative standard deviation (RSD) was always less than 10.6%. The recovery of anthracyclines was assessed at two concentrations of the range tested (0.1 and 2.0 microg/L) and it ranged from 87.7% (daunorubicin) to 102.0% (doxorubicin) and from 79.1% (daunorubicin) to 90.7% (idarubicin) for the lower and the higher level, respectively, with a RSD always less than 9.1%. The uncertainty of the present assay was also evaluated and the combined uncertainty was always less than 20% over all the days of the validation study. This is the first method that makes use of LC/MS/MS for the biological monitoring of occupational exposure to anthracyclines.

A validated assay for measuring doxorubicin in biological fluids and tissues in an isolated lung perfusion model: matrix effect and heparin interference strongly influence doxorubicin measurements

Doxorubicin is an antineoplasic agent active against sarcoma pulmonary metastasis, but its clinical use is hampered by its myelotoxicity and its cumulative cardiotoxicity, when administered systemically. This limitation may be circumvented using the isolated lung perfusion (ILP) approach, wherein a therapeutic agent is infused locoregionally after vascular isolation of the lung. The influence of the mode of infusion (anterograde (AG): through the pulmonary artery (PA); retrograde (RG): through the pulmonary vein (PV)) on doxorubicin pharmacokinetics and lung distribution was unknown. Therefore, a simple, rapid and sensitive high-performance liquid chromatography method has been developed to quantify doxorubicin in four different biological matrices (infusion effluent, serum, tissues with low or high levels of doxorubicin). The related compound daunorubicin was used as internal standard (I.S.). Following a single-step protein precipitation of 500 microl samples with 250 microl acetone and 50 microl zinc sulfate 70% aqueous solution, the obtained supernatant was evaporated to dryness at 60 degrees C for exactly 45 min under a stream of nitrogen and the solid residue was solubilized in 200 microl of purified water. A 100 microl-volume was subjected to HPLC analysis onto a Nucleosil 100-5 microm C18 AB column equipped with a guard column (Nucleosil 100-5 microm C(6)H(5) (phenyl) end-capped) using a gradient elution of acetonitrile and 1-heptanesulfonic acid 0.2% pH 4: 15/85 at 0 min-->50/50 at 20 min-->100/0 at 22 min-->15/85 at 24 min-->15/85 at 26 min, delivered at 1 ml/min. The analytes were detected by fluorescence detection with excitation and emission wavelength set at 480 and 550 nm, respectively. The calibration curves were linear over the range of 2-1000 ng/ml for effluent and plasma matrices, and 0.1 microg/g-750 microg/g for tissues matrices. The method is precise with inter-day and intra-day relative standard deviation within 0.5 and 6.7% and accurate with inter-day and intra-day deviations between -5.4 and +7.7%. The in vitro stability in all matrices and in processed samples has been studied at -80 degrees C for 1 month, and at 4 degrees C for 48 h, respectively. During initial studies, heparin used as anticoagulant was found to profoundly influence the measurements of doxorubicin in effluents collected from animals under ILP. Moreover, the strong matrix effect observed with tissues samples indicate that it is mandatory to prepare doxorubicin calibration standard samples in biological matrices which would reflect at best the composition of samples to be analyzed. This method was successfully applied in animal studies for the analysis of effluent, serum and tissue samples collected from pigs and rats undergoing ILP.