Use of a Glass Membrane Pumping Emulsification Device Improves Systemic and Tumor Pharmacokinetics in Rabbit VX2 Liver Tumor in Transarterial Chemoembolization.

PURPOSE: To evaluate the phamacokinetics of epirubicin in conventional transarterial chemoembolization using a developed pumping emulsification device with a microporous glass membrane in VX2 rabbits. MATERIALS AND METHODS: Epirubicin solution (10 mg/mL) was mixed with ethiodized oil (1:2 ratio) using the device or 3-way stopcock. Forty-eight rabbits with VX2 liver tumor implanted 2 weeks prior to transarterial chemoembolization were divided into 2 groups: a device group (n = 24) and a 3-way-stopcock group (n = 24). Next, 0.5 mL of emulsion was injected into the hepatic artery, followed by embolization using 100-300-µm microspheres. The serum epirubicin concentrations (immediately after, 5 minutes after, and 10 minutes after) and the tumor epirubicin concentrations (20 minutes after and 48 hours after) were measured after transarterial chemoembolization. Histopathologic evaluation was performed with a fluorescence microscope. RESULTS: The area under the curve and maximum concentrations of epirubicin in plasma were 0.45 ± 0.18 µg min/mL and 0.13 ± 0.06 µg/mL, respectively, in the device group and 0.71 ± 0.45 µg min/mL and 0.22 ± 0.17 µg/mL, respectively, in the 3-way-stopcock group (P = .013 and P = .021, respectively). The mean epirubicin concentrations in VX2 tumors at 48 hours in the device group and the 3-way-stopcock group were 13.7 ± 6.71 and 7.72 ± 3.26 µg/g tissue, respectively (P = .013). The tumor necrosis ratios at 48 hours were 62 ± 11% in the device group and 51 ± 13% in the 3-way-stopcock group (P = .039). CONCLUSIONS: Conventional transarterial chemoembolization using the pumping emulsification device significantly improved the pharmacokinetics of epirubicin compared to the current standard technique using a 3-way stopcock.

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.

Identification of differential gene expression related to epirubicin-induced cardiomyopathy in breast cancer patients.

BACKGROUND: Epirubicin is a potent chemotherapeutic agent for the treatment of breast cancer. However, it may lead to cardiotoxicity and cardiomyopathy, and no reliable biomarker was available for the early prediction of epirubicin-induced cardiomyopathy. METHODS: Global gene expression changes of peripheral blood cells were studied using high-throughput RNA sequencing in three pair-matched breast cancer patients (patients who developed symptomatic cardiomyopathy paired with patients who did not) before and after the full session of epirubicin-based chemotherapy. Functional analysis was conducted using gene ontology and pathway enrichment analysis. RESULTS: We identified 13 significantly differentially expressed genes between patients who developed symptomatic epirubicin-induced cardiomyopathy and their paired control who did not. Among them, the upregulated Bcl-associated X protein was related to "apoptosis," while the downregulated 5'-aminolevulinate synthase 2 (ALAS2) was related to both "glycine, serine, and threonine metabolism" and "porphyrin and chlorophyll metabolism" in pathway enrichment analysis. CONCLUSIONS: ALAS2 and the metabolic pathways which were involved may play an important role in the development of epirubicin-induced cardiomyopathy. ALAS2 may be useful as an early biomarker for epirubicin-induced cardiotoxicity detection.

Cerium-doped flower-shaped ZnO nano-crystallites as a sensing component for simultaneous electrochemical determination of epirubicin and methotrexate.

A glassy carbon electrode (GCE) was modified with cerium-doped ZnO nanoflowers (Ce-ZnO/GCE) to obtain a sensor for direct simultaneous detection of the cancer drugs epirubicin and methotrexate. XRD, SEM and EDX techniques were used to characterize their morphology and structure. Electrochemical impedance spectroscopy was applied to characterize the electrochemical features of the modified GCE. The experimental conditions were optimized. Diffusion coefficients and heterogeneous rate constants were determined for the oxidation of epirubicin. The differential pulse voltammetric response to epirubicin has a peak near 0.7 V (vs. Ag/AgCl at a scan rate of 50 mV s-1) and is linear in the 0.01 to 600 µM concentration range, and the detection limit is 2.3 nM (S/N = 5). The differential pulse voltammetric response to methotrexate has a peak near 0.75 V (vs. Ag/AgCl and the same scan rate) and is linear in the 0.01 to 500 µM concentration range, and the detection limit is 6.3 nM (S/N = 5). The method was applied to the simultaneous determination of epirubicin and methotrexate in pharmaceutical injections and in spiked diluted blood specimens. Graphical abstractSchematic of an electrochemical sensor based on Ce-doped ZnO nano-flowers modified glassy carbon electrode for detecting epirubicin.

Technetium-99m radiolabeling and biological study of epirubicin for in vivo imaging of multi-drug-resistant Staphylococcus aureus infections via single photon emission computed tomography.

The development of functional imaging is a promising strategy for diagnosis and treatment of infectious and cancerous diseases. In this study, epirubicin was developed as a [99m Tc]-labeled radiopharmaceutical for the imaging of multi-drug-resistant Staphylococcus aureus infections. The labeling was carried out using sodium pertechnetate (Na99m TcO4 ; ~370 MBq). The other parameters such as amount of ligand, reducing agent (SnCl2 .2H2 O), and pH were optimized. The highest labeling yield ≥96.98% was achieved when 0.3 mg epirubicin, 13 µg SnCl2 .2H2 O, and ~370 MBq Na99m TcO4 were incubated at pH 7 for 15 min in the presence of ascorbic acid at room temperature. Radiochemical purity, stability, charge, and glomerular filtration rate were studied to evaluate the biological compatibility for in vivo administration. Biodistribution investigations showed radiotracer uptake (13.89 ± 1.56% ID/gm organ) by liver and 7.79 ± 0.38% ID/gm organ by kidneys at 30 min post-injection which promisingly wash out at 24 hr post-injection. Scintigraphy study showed selective uptake in S. aureus-infected tissues in contrast to turpentine oil-induced inflamed tissues. Target-to-non-target ratio (6.7 ± 0.05) was calculated at 1 hr post-injection using SPECT gamma camera. The results of this study reveal that the [99m Tc]-epirubicin can be a choice of imaging and monitoring the treatment process of multi-drug resistant S. aureus bacterial infections.

RP-HPLC-UV Method for Estimation of Fluorouracil-Epirubicin-Cyclophosphamide and Their Metabolite Mixtures in Human Plasma (Matrix).

A combination of 5-fluorouracil (FU), epirubicin (EP) and cyclophosphamide (CP) is routinely employed in the treatment of breast cancer. The objective of this study was to develop a reverse phase high-performance liquid chromatography (HPLC)-UV method for simultaneous quantitative analysis of the triple-drug and their metabolites in plasma. RP-HPLC system with a C18 column and a diode array detector was employed. The plasma samples were precipitated with acetonitrile and the supernatant was dried under a flow of nitrogen gas. The mobile phase comprised of two combinations, water (pH 4.0) and methanol (98:2 v/v), and water (pH 4.0):methanol:acetonitrile (70:13:17 v/v/v). The retention times for the compounds were determined and the parameters of validation established in plasma indicated the robustness and reliability. The corresponding HPLC peaks were confirmed using electron spray ionization mass spectrometry. FU and metabolites had a recovery of >93%; EP, epirubicinol and CP were >78% from plasma. Stability at 28-30°C in water (pH 4.0) of FU, 5,6-dihydro-5-fluorouracil and EP were higher followed by CP, EPol, fluorodeoxyuridine and fluorouridine (FUR). Storage of the drug-spiked plasma at -80°C assessed for 72 h showed a small but significant (P < 0.05) change in the recovery of FUR and EP. The method was validated in patient's plasma samples (n = 6).

Polysialic acid-polyethylene glycol conjugate-modified liposomes as a targeted drug delivery system for epirubicin to enhance anticancer efficiency.

Polysialic acid (PSA) is a nonimmunogenic and biodegradable polysaccharide. In recent years, PSA has shown its potential applications to cancer treatment. In this study, PSA-polyethylene glycol (PEG) conjugate was synthesized for the decoration of epirubicin (EPI)-loaded liposomes. The study aimed to evaluate the PSA-PEG conjugated modified liposomes (EPI-PSL) in vitro and in vivo to investigate the role of PSA on physicochemical characteristics and antitumor activity in PEGylated liposomes. EPI-PSL showed a particle size of 116.9 ± 5.2 nm, zeta potential of - 40.3 ± 3.5 mV, and encapsulation efficiency of 99.1 ± 1.5%. The results of in vitro release experiments showed a delayed release of EPI from EPI-PSL. Greater cellular uptake of EPI-PSL was observed compared with PEGylated liposomes (EPI-PL) in B16 cells. Cytotoxicity studies suggested that EPI-PSL exhibited stronger cytotoxic activity than EPI-PL. Though EPI-PSL exhibited comparable blood plasma profiles with EPI-PL, biodistribution studies proved that the distribution of EPI-PSL in tumors was more than that of EPI-PL. The superior antitumor efficacy of EPI-PSL was also verified in the B16 xenograft mouse model with a reduction in systemic toxicity. In conclusion, these results therefore indicated that PSA-modified PEGylated liposomes may represent an excellent anticancer drug delivery system for targeted cancer therapy.

Design an aptasensor based on structure-switching aptamer on dendritic gold nanostructures/Fe3O4@SiO2/DABCO modified screen printed electrode for highly selective detection of epirubicin.

The present work describes a label free electrochemical aptasensor for selective detection of epirubicin. In this project, 5'-thiole terminated aptamer was self-assembled on carbon screen printed electrode, which modified with electrodeposited gold nanoparticles on magnetic double-charged diazoniabicyclo [2.2.2] octane dichloride silica hybrid (Fe3O4@SiO2/DABCO) by Au-S bond. The interactions of epirubicin with aptamer on the AuNPs/Fe3O4@SiO2/DABCO/SPE have been studied by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy. Under optimized conditions, the peak current of epirubicin increased linearly with increasing epirubicin concentration, due to the switching in the aptamer conformation and formation of aptamer- epirubicin complex instead of aptamer on the modified electrode surface. The Apt/AuNPs/Fe3O4@SiO2/DABCO/SPE is sensitive, selective and has two linear range from 0.07µM to 1.0µM and 1.0µM to 21.0µM with a detection limit of 0.04µM. The applicability of the aptasensor was successfully assessed by determination of epirubicin in a human blood serum sample.

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.

Hepatic uptake of epirubicin by isolated rat hepatocytes and its biliary excretion after intravenous infusion in rats.

Anthracycline anticancer agents are widely used in the cancer chemotherapy for hepatocelluar carcinoma. However, accurate kinetic analyses of the hepatocellular uptake and efflux of the drugs have not been reported. We, therefore, investigated the hepatobiliary transport of epirubicin, an anthracycline derived antibiotic, after intravenous (i.v.) infusion in rats. The hepatic uptake mechanisms of epirubicin were also investigated in isolated rat hepatocytes. To analyze epirubicin levels in the biological samples, we used an HPLC-based method which has been validated for a kinetic study by suitable criteria. The uptake process of epirubicin by the hepatocytes revealed one saturable component, with a Km of 99.1 µg/mL and Vmax of 3.70 µg/min/10(6) cells. The initial uptake velocity of epirubicin was significantly inhibited in a temperature-dependent manner. The velocity was also reduced in the presence of metabolic inhibitors such as rotenone or carbonylcyanide-p-(trifluoromethoxy)-phenylhydrazone. Substrates for organic anion transporters such as bromosulfophthalein and taurocholate significantly inhibited the initial uptake velocity of epirubicin. We also attempted to determine the hepatobiliary transport of epirubicin after i.v. infusion in vivo. At steady-state after i.v. infusion of epirubicin (10-160 µg/min/kg), the drug was extensively accumulated in the liver, followed by excretion into bile. Furthermore, the CLbile,plasma and CLbile,liver decreased with a corresponding increase in the Css,plasma and Css,liver. In conclusion, present studies using isolated rat hepatocytes and in vivo i.v. infusion demonstrate that epirubicin is likely to be taken up into liver cells via organic anion transporting polypeptides, and that its biliary excretion might be mediated via specific transporters.

Efficient human breast cancer xenograft regression after a single treatment with a novel liposomal formulation of epirubicin prepared using the EDTA ion gradient method.

Liposomes act as efficient drug carriers. Recently, epirubicin (EPI) formulation was developed using a novel EDTA ion gradient method for drug encapsulation. This formulation displayed very good stability and drug retention in vitro in a two-year long-term stability experiment. The cryo-TEM images show drug precipitate structures different than ones formed with ammonium sulfate method, which is usually used to encapsulate anthracyclines. Its pharmacokinetic properties and its efficacy in the human breast MDA-MB-231 cancer xenograft model were also determined. The liposomal EPI formulation is eliminated slowly with an AUC of 7.6487, while the free drug has an AUC of only 0.0097. The formulation also had a much higher overall antitumor efficacy than the free drug.

Risk factors for the leakage of chemotherapeutic agents into systemic circulation after transcatheter arterial chemoembolization of hepatocellular carcinoma.

This prospective study was to investigate the possible risk factors for the leakage of chemotherapeutic agent into the systemic circulation after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Peripheral plasma concentrations of chemotherapeutic agents were determined at 1 hour and 72 hours after TACE by high-performance liquid chromatography in 53 patients. HCC were divided into three types namely single nodule (<5cm), multiple nodules (all <5cm), and main nodule measuring 5cm or more. Forty-four patients (83%) showed detectable chemotherapeutic concentrations within 72 hours after TACE. Patients with single nodular-type HCC had lower incidence of detectable plasma chemotherapeutic agents after TACE than the other two groups (all p<0.05). The injected doses of lipiodol, epirubicin, and mitomycin C were lower in patients without detection than in patients with detectable chemotherapeutic agents (all p<0.05). Multivariate logistic regression showed that tumor type and injected dose of lipiodol were two independent risk factors for the leakage of mitomycin C at 1 hour after TACE (all p<0.05), and the injected dose of mitomycin C was the risk factor for the leakage of epirubicin at 1 hour after TACE (p<0.05). In conclusion, multiple nodular type and large nodule measuring 5cm or more have a risk of leakage of mitomycin C after TACE. Injected dose of lipiodol and mitomycin C as risk factor for the leakage of mitomycin C and epirubicin respectively may be because of competition of their injected volume within the limited space of target.

Substantial variation in transplacental transfer of chemotherapeutic agents in a mouse model.

OBJECTIVE: Data on the transplacental transfer of chemotherapeutic agents are lacking. We aimed to measure the maternofetal transfer of cytotoxic drugs in a mouse model. STUDY DESIGN: The transplacental transfer of doxorubicin (9 mg/kg), epirubicin (11 mg/kg), vinblastine (6 mg/kg), carboplatin (50 mg/kg), paclitaxel (10 mg/kg), and cytarabine (100 mg/kg) was tested in a C57/Bl6J mouse model. Ninety minutes after intravenous (IV) drug injection on gestational day 18.5, maternal and fetal blood were collected simultaneously. Plasma drug levels were determined using high performance liquid chromatography or atomic absorption spectrometry. RESULTS: Fetal plasma concentrations of doxorubicin, epirubicin, vinblastine, and cytarabine were 5.1% ± 0.6% (n = 8), 4.8% ± 3.8% (n = 8), 13.8% ± 5.8% (n = 6), and 56.7% ± 22.6% (n = 6) of the maternal concentrations, respectively. Total platinum passed the mouse placenta easily (117.0% ± 38.9%, n = 6). Paclitaxel could not be detected in fetal plasma samples (n = 6). CONCLUSIONS: Substantial variations in transplacental transfer were noted among the tested drugs. Current findings contribute to the understanding of reported pregnancy outcomes in humans.

Transplacental transfer of anthracyclines, vinblastine, and 4-hydroxy-cyclophosphamide in a baboon model.

OBJECTIVE: The paucity of data on the fetal effects of prenatal exposure to chemotherapy prompted us to study transplacental transport of chemotherapeutic agents. METHODS: Fluorouracil-epirubicin-cyclophosphamide (FEC) and doxorubicin-bleomycin-vinblastine-dacarbazine (ABVD) were administered to pregnant baboons. At predefined time points over the first 25 h after drug administration, fetal and maternal blood samples, amniotic fluid (AF), urine, fetal and maternal tissues, and cerebrospinal fluid (CSF) were collected. High-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) were used for bioanalysis of doxorubicin, epirubicin, vinblastine, and cyclophosphamide. RESULTS: In nine baboons, at a median gestational age of 139 days (range, 93-169), FEC 100% (n = 2), FEC 200% (n=1), ABVD 100% (n = 5), and ABVD 200% (n = 1) were administered. The obtained ratios of fetal/maternal drug concentration in the different simultaneously collected samples were used as a measure for transplacental transfer. Fetal plasma concentrations of doxorubicin and epirubicin averaged 7.5 ± 3.2% (n = 6) and 4.0 ± 1.6% (n = 8) of maternal concentrations, respectively. Fetal tissues contained 6.3 ± 7.9% and 8.7 ± 8.1% of maternal tissue concentrations for doxorubicin and epirubicin, respectively. Vinblastine concentrations in fetal plasma averaged 18.5 ± 15.5% (n=9) of maternal concentrations. Anthracyclines and vinblastine were neither detectable in maternal nor in fetal brain/CSF. 4-Hydroxy-cyclophosphamide concentrations in fetal plasma and CSF averaged 25.1 ± 6.3% (n = 3) and 63.0% (n = 1) of the maternal concentrations, respectively. CONCLUSION: This study shows limited fetal exposure after maternal administration of doxorubicin, epirubicin, vinblastine, and 4-hydroxy-cyclophosphamide.

Simultaneous determination of anthracyclines and taxanes in human serum using online sample extraction coupled to high performance liquid chromatography with UV detection.

An online SPE-LC method that can determine both anthracyclines and taxanes simultaneously in human serum samples is reported. The entire method of extraction, separation and UV detection was achieved online by column switching between an SPE column (Biotrap 500 (20 x 4 mm)) and an analytical column (Zorbax XDB C18, 150 x 4.6 mm, 5 microm) with a 23 min total cycle time. The method is linear (r(2)>0.998) over the range of 0.5-25 microg/mL. The analytes of interest are retained on the SPE column with good recovery (84-117%), while proteins and other serum components elute to waste. This online clean-up is much faster (150 s) and less manual than traditional off-line extraction methods. Using 0.1 mL spiked serum samples, the LOQ was 0.5 microg/mL. Intra- and inter-day precision were acceptable (< or = 15% RSD) at and above the LOQ. The method was applied to the analysis of serum samples from patients undergoing chemotherapy with these agents.

Gemcitabine and epirubicin plasma concentration-related excretion in saliva in patients with non-small cell lung cancer.

AIM: The excretion in saliva of gemcitabine and its metabolite 2',2'-difluorodeoxyuridine (dFdU) as well as epirubicin (Epi) and its metabolite epirubicinol (Epi-ol) was studied in patients with non-small cell lung cancer, treated with gemcitabine plus epirubicin. METHODS: Patients (n = 12) were treated with gemcitabine 1125 mg/m, followed by Epi 100 mg/m. Blood, saliva, and oral mucosa cells were collected during 22 hours for analysis of gemcitabine, Epi, and their metabolites. Gemcitabine, dFdU, Epi, and Epi-ol were quantified by high-performance liquid chromatography. RESULTS: Gemcitabine was cleared rapidly from plasma and undetectable after 3 hours in all patients. Gemcitabine was detectable in saliva during only the first hour after infusion. The Cmax in saliva was 0.66 +/- 0.61 mg/L, and the saliva to plasma ratio (S/P ratio) was 0.038 +/- 0.037. The Cmax of dFdU was reached 1.5-2 hours after gemcitabine infusion and was 1.03 +/- 0.63 mg/L. The dFdU S/P ratios gradually increased from 0.021 +/- 0.013 at t = 1 hour to 0.050 +/- 0.027 at t = 6 hours after infusion. Epi displayed a triexponential plasma concentration-time profile. The Epi and Epi-ol concentrations in saliva at t = 6 hours after administration were 55 +/- 27 and 9 +/- 9 microg/L, respectively, and decreased to 28 +/- 14 and 7 +/- 4 microg/L, respectively, at t = 22 hours. The corresponding S/P ratios were 1.28 +/- 0.73 and 0.36 +/- 0.31 at t = 6 hours and 1.72 +/- 1.00 and 0.62 +/- 0.34 at t = 22 hours, respectively. The amount of Epi in mucosal cells ranged from 135-598 ng per 10 cells at t = 3 hours and decreased to 33-196 ng per 10 cells at t = 22 hours. CONCLUSION: Gemcitabine and Epi, as well as their main metabolites dFdU and Epi-ol, are excreted in detectable amounts in saliva, although their absolute concentrations remain relatively low.

[Pharmacokinetics of epirubicin hydrochloride long-circulating thermosensitive liposomes in rat plasma].

To develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of epirubicin hydrochloride (EPI) in rat plasma, daunorubicin hydrochloride was used as internal standard. The plasma samples were deproteinated with methanol, and separation was performed on a reversed-phase CAPCELL PAK C18 column (3.0 mm x 50 mm, 3 microm). The mobile phase contained methanol-0.1% formic acid (80:20). Detection was carried out by multiple reaction monitoring on a HP1200-6410 QQQ LC/MS system. Different preparations of EPI solution, EPI-LIP (EPI-liposome) and EPI-LTSL (EPI-thermosensitive liposome) was administered in rats by i.v with the same dosage (12 mg kg(-1)). The pharmacokinetic model and parameters were fitted and calculated by the DAS ver2.0 software. The calibration curve was linear in the range of 0.01-50 microg mL(-1). The limit of quantification was 0.01 microg mL(-1). RSDs of intra- and interbatch precisions were all less than 11.9%. The average extract recovery was 89.3% and 92.1%, respectively. The pharmacokinetics of EPI in rats with all preparations were fitted to three compartments, which all fast distributed and slowly eliminated. The t1/2 alpha, t1/2 beta, t1/2 gamma, AUC(0-infinity), and MRT(0-infinity) of EPI-LTSL group were 7.5, 1.3, 12.6, 12.9, 3.7 times those of EPI solution group; and 1.6, 1.4, 12.3, 2.9, 2.6 times those of EPI-LIP group. Moreover, the CL of the latter two groups was about 13.4 times of the former EPI-LTSL group. EPI-LTSL can significantly improve AUC and prolong the circulation time of EPI in rat plasma.

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.

Determination of epirubicin and its metabolite epirubicinol in saliva and plasma by HPLC.

We present a high-performance liquid chromatography (HPLC) method suitable for the analysis of epirubicin and its metabolite epirubicinol in saliva and plasma. Preparation of saliva and plasma samples was performed by extraction of analytes with a chloroform:2-propanol mixture (6:1, vol/vol) and evaporation of the organic phase to dryness under vacuum at a temperature of approximately 45 degrees C. The chromatographic analysis was carried out by reversed-phase isocratic elution of the anthracyclines with a Chromsep stainless steel HPLC column (150 x 4.6 mm I.D.) filled with Nucleosil 100 S C(18) material, particle size 5 micro m. The detection was accomplished by spectrofluorimetry at excitation and emission wavelengths of 474 and 551 nm, respectively. The anthracyclines eluted within 10 min of injection, and the method appeared to be specific. The method is linear over a concentration range of 5 to 1000 micro g/L for epirubicin and 2 to 400 micro g/L for epirubicinol (r > 0.99) in both saliva and plasma. The recoveries from saliva and plasma of epirubicin, epirubicinol, and the internal standard doxorubicin were 88.9 and 69.0%, 87.6 and 77.3%, and 80 and 67.9%, respectively. The lower limit of quantification was 5 micro g/L for epirubicin and 2 micro g/L for epirubicinol. The method proved to be precise and accurate, as the within-day and between-day coefficients of variation were less than 10%. Overall results indicate that our method is suitable for the bioanalysis of epirubicin and epirubicinol in saliva as well as plasma.