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A new micellar electrokinetic capillary chromatographic (MEKC) method has been developed and optimized for simultaneous quantitation of doxorubicin (Dox) and fullerenol (Frl) in rat serum. The separation was carried out in a capillary (48.5-40 cm to the detector - 50 µm id fused-silica capillary with bubble cell, 150 µm) at an applied voltage of 25 kV and temperature of 25 °C. For the background electrolyte 10 mmol L - 1 borate buffer pH 9.3 plus 15 mmol L-1 phosphate buffer pH 7.0 (with the final pH of the mixture adjusted to 7.0 with HCl), with added 10 % ( V / V ) methanol, and 15 mmol L-1 sodium dodecyl sulfate as a surfactant, were used. The hydrodynamic injection was carried out at 5.0 kPa during the period of 100 s. Linear calibration curves were established over the concentration range 0.5-500.0 mg L - 1 for Dox and 10.0-500.0 mg L - 1 for Frl (at 234 nm). The proposed MEKC procedure was fully validated and applied for the deter mination of Dox and Frl in Wistar rats after intra pe ritoneal administration of both molecules., (© 2024 Rade Injac et al., published by Sciendo.)

Background: Aidi Injection (ADI), a Chinese herbal preparation with anti-cancer activity, is used for the treatment of hepatocellular carcinoma (HCC). Several clinical studies have shown that co-administration of ADI with doxorubicin (DOX) is associated with reduced toxicity of chemotherapy, enhanced clinical efficacy and improved quality of life for patients. However, limited information is available about the herb-drug interactions between ADI and DOX. The study aimed to investigate the pharmacokinetic mechanism of herb-drug interactions between ADI and DOX in a rat model of HCC., Methods: Experimental HCC was induced in rats by oral administration of diethylnitrosamine. The HCC rats were pretreated with ADI (10 mL/kg, intraperitoneal injection) for 14 consecutive days prior to administration of DOX (7 mg/kg, intravenous injection) to investigate pharmacokinetic interactions. Plasma concentrations of DOX and its major metabolite, doxorubicinol (DOXol), were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)., Results: Preadministration of ADI significantly altered the pharmacokinetics of DOX in HCC rats, leading to increased plasma concentrations of both DOX and DOXol. The area under the plasma drug concentration-time curve (AUCs) of DOX and DOXol in rats pretreated with ADI were 3.79-fold and 2.92-fold higher, respectively, than those in control rats that did not receive ADI., Conclusions: Increased levels of DOX and DOXol were found in the plasma of HCC rats pretreated with ADI., (© 2021. The Author(s).)

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

Introduction: Doxorubicin is an anthracycline antibiotic used as an anticancer agent. Long-term use of this anticancer agent could accumulate its metabolite, doxorubicinol, and cause cardiomyopathy, due to its cardiotoxicity. This cardiotoxic effect depends on the amount of doxorubicin and doxorubicinol accumulated in the body. This study aimed to analyze doxorubicin and doxorubicinol levels in the blood plasma of breast cancer patients., Methods: Participants of this study were 30 breast cancer patients who had received doxorubicin in their therapy regimen. The samples were analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), with the Acquity UPLC BEH C18 Waters chromatography column (2.1 x 100 mm : 1.7 μm). Plasma (250 μL) samples were prepared by protein precipitation, using methanol. The mobile phase consisted of 0.1% acetic acid (eluent A) and acetonitrile (eluent B), with gradient elution; the flow rate was 0.15 mL/min and runtime, 7 min., Results and Discussion: This method was linear in the range of 1-1000 ng/mL for doxorubicin and 0.5-500 ng/mL for doxorubicinol. This method was successfully used to analyze doxorubicin and doxorubicinol, simultaneously, using hexamethylphosphoramide as the internal standard, in the plasma of breast cancer patients. Results showed that the measured concentrations of doxorubicin and doxorubicinol ranged between 12.54-620.01 ng/mL and 1.10-27.00 ng/mL, respectively. The measured cumulative doses of doxorubicin ranged between 48.76 and 319.01 mg/m 2 ; thus, the risk of cardiomyopathy in the surveyed patients was under 4%, according to literature., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Harahap et al.)

For cancer treatment, intratumoral drug injection has many limitations and not commonly adopted. The poly[lactic-co-glycolic acid] (PLGA) has emerged as a promising vehicle to enhance the in vitro/in vivo characteristic of various drugs. We prepared doxorubicin-PLGA microspheres (DOX-PLGA MSs) using the electrospray method. An in vitro elution method was employed to evaluate the release of DOX from the MSs. We performed an in vivo study on rats, in which we directly injected DOX-PLGA MSs into the liver. We measured liver and plasma DOX concentrations to assess local retention and systemic exposure. The mean diameter of the MSs was 6.74 ± 1.01 μm. The in vitro DOX release from the MSs exhibited a 12.3 % burst release on day 1, and 85.8 % of the drug had been released after 30 days. The in vivo tests revealed a higher local drug concentration at the target lobe of the liver than at the adjacent median lobe. In the first week, the DOX concentration in the peripheral blood of the MS group was lower than that of the direct DOX injection group. Based on the measured intrahepatic concentration and plasma pharmacokinetic profiles, DOX-PLGA MSs could be suitable vectors of chemotoxic agents for intratumoral injection., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Despite its cardiotoxicity doxorubicin is widely used for the treatment of paediatric malignancies. Current treatment regimens appear to be suboptimal as treatment strategies vary and do not follow a clear pharmacological rationale. Standardisation of dosing strategies in particular for infants and younger children is required but is hampered by scarcely defined exposure-response relationships. The aim is to provide a rational dosing concept allowing for a reduction of variability in systemic therapy intensity and subsequently unforeseen side effects., Methods: Doxorubicin plasma concentrations in paediatric cancer patients were simulated for different treatment schedules using a population pharmacokinetic model which considers age-dependent differences in doxorubicin clearance. Overall drug exposure and peak concentrations were assessed. Simulation results were used to support a three round Delphi consensus procedure with the aim to clarify the pharmacological goals of doxorubicin dosing in young children. A group of 28 experts representing paediatric trial groups and clinical centres were invited to participate in this process., Results: Pharmacokinetic simulations illustrated the substantial differences in therapy intensity associated with current dosing strategies. Consensus among the panel members was obtained on a standardised a priori dose adaptation that individualises doxorubicin doses based on age and body surface area targeting uniform drug exposure across children treated with the same protocol. Further, a reduction of peak concentrations in very young children by prolonged infusion was recommended., Conclusions: An approach to standardise current dose modification schemes in young children is proposed. The consented concept takes individual pharmacokinetic characteristics into account and involves adaptation of both the dose and the infusion duration potentially improving the safety of doxorubicin administration.

Doxorubicin, an anthracycline antitumor antibiotic, acts as a cancer treatment by interfering with the function of DNA. Herein, liquid chromatography-tandem mass spectrometry was for the first time developed and validated for the simultaneous determination of doxorubicin and its major metabolites doxorubicinol, doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The liquid-liquid extraction of a 10 μL mouse plasma sample with chloroform:methanol (4:1, v / v ) and use of the selected reaction monitoring mode led to less matrix effect and better sensitivity. The lower limits of quantification levels were 0.5 ng/mL for doxorubicin, 0.1 ng/mL for doxorubicinol, and 0.01 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone. The standard curves were linear over the range of 0.5-200 ng/mL for doxorubicin; 0.1-200 ng/mL for doxorubicinol; and 0.01-50 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The intra and inter-day relative standard deviation and relative errors for doxorubicin and its four metabolites at four quality control concentrations were 0.9-13.6% and -13.0% to 14.9%, respectively. This method was successfully applied to the pharmacokinetic study of doxorubicin and its metabolites after intravenous administration of doxorubicin at a dose of 1.3 mg/kg to female BALB/c nude mice.

Background: Bladder hyperthermic intracavitary chemotherapy (HIVEC) has good effectiveness for bladder cancer, but conventional HIVEC systems lack precision and convenient application. To test the safety of a new HIVEC device (BR-TRG-II-type) in pigs and to perform a preliminary clinical trial in patients with bladder cancer., Methods: This device was tested on six pigs to optimize the temperature and time parameters. Then, 165 patients (HIVEC after transurethral resection (TUR), n = 128; or HIVEC, n = 37) treated between December 2006 and December 2016 were recruited. Mitomycin C (MMC) was the chemotherapeutic agent. A serum pharmacokinetic study was performed. The primary endpoints were tumor recurrence, disease-free survival (DFS), and cumulative incidence rate (CIR) during follow-up. The adverse effects were graded., Results: The animal experiment showed that 45 °C for 1 h was optimal. HIVEC was successful, with the infusion tube temperature stably controlled at about 45 °C, and outlet tube temperature of about 43 °C in all patients, for three sessions. Serum MMC levels gradually increased during HIVEC and decreased thereafter. The mean DFS was 39 ± 3.21 months (ranging from 8 to 78 months), and the DFS rate was 89.1% during follow-up. No adverse events occurred., Conclusion: The use of the BR-TRG-II-type HIVEC device is feasible for the treatment of bladder cancer. Future clinical trials in patients with different stages of bladder cancer will further confirm the clinical usefulness of this device., Trial Registration: chictr.org.cn: ChiCTR1900022099 (registered on Mar. 252,019). Retrospectively registered.

Doxorubicin (DOX), an anthracycline molecule, is currently one of the most widely used anticancer drugs in clinics. Systematic treatment of patients with DOX is known to be accompanied by several unpleasant side effects due to the toxicity of the drug. Thus, monitoring of DOX concentration in serum samples has become increasingly important to avoid side effects and ensure therapeutic efficiency. In this study, we discuss the construction of a disposable electrochemical sensor for the direct monitoring of DOX in clinical blood samples. The sensor is based on coating a gold electrode in a flexible integrated electrode construct formed on polyimide sheets using photolithography, with nitrogen-doped reduced graphene oxide (N-rGO) suspended in chitosan. Under optimized conditions, a linear relationship between the oxidative peak current and the concentration of DOX in the range of 0.010-15 μM with a detection limit of 10 nM could be achieved. The sensor was adapted to monitor DOX in serum samples of patients under anticancer treatment. Graphical abstract.

Objective: Thermosensitive liposomal doxorubicin (TSL-Dox) is a promising stimuli-responsive nanoparticle drug delivery system that rapidly releases the contained drug in response to hyperthermia (HT) (>40 °C). Combined with localized heating, TSL-Dox allows highly localized delivery. The goals of this study were to demonstrate that real-time fluorescence imaging can visualize drug uptake during delivery, and can predict tumor drug uptake. Methods: Nude mice carrying subcutaneous tumors (Lewis lung carcinoma) were anesthetized and injected with TSL-Dox (5 mg/kg dose). Localized HT was induced by heating tumors for 15, 30 or 60 min via a custom-designed HT probe placed superficially at the tumor location. In vivo fluorescence imaging (excitation 523 nm, emission 610 nm) was performed before, during, and for 5 min following HT. After imaging, tumors were extracted, drug uptake was quantified by high-performance liquid chromatography, and correlated with in vivo fluorescence. Plasma samples were obtained before and after HT to measure TSL-Dox pharmacokinetics. Results: Local drug uptake could be visualized in real-time during HT. Compared to unheated control tumors, fluorescence of heated tumors increased by 4.6-fold (15 min HT), 9.3-fold (30 min HT), and 13.2-fold (60 min HT). HT duration predicted tumor drug uptake ( p  = .02), with tumor drug concentrations of 4.2 ± 1.3 µg/g (no HT), 7.1 ± 5.9 µg/g (15 min HT), 14.1 ± 6.7 µg/g (30 min HT) and 21.4 ± 12.6 µg/g (60 min HT). There was good correlation ( R 2  = 0.67) between fluorescence of the tumor region and tumor drug uptake. Conclusions: Real-time in vivo fluorescence imaging can visualize drug uptake during delivery, and can predict tumor drug uptake.

Background: Monitoring of mycophenolic acid (MPA) levels may be useful for effective mycophenolate mofetil (MMF) dosing. However, whether commonly obtained trough levels are an acceptable method of surveillance remains debatable. We hypothesized that trough levels of MPA would be a poor predictor of area under the curve (AUC) for MPA., Methods: A total of 51 patients with lupus nephritis who were on MMF 1500 mg twice a day and had a 4-h AUC done were included in this study. MPA levels were measured prior to (C0) and at 1 (C1), 2 (C2) and 4 (C4) h, followed by 1500 mg of MMF. The MPA AUC values were calculated using the linear trapezoidal rule. Regression analysis was used to examine the relationship between the MPA trough and AUC. Differences in the MPA trough and AUC between different clinical and demographic categories were compared using t-tests., Results: When grouped by tertiles there was significant overlap in MPA, AUC 0-4 and MPA trough in all tertiles. Although there was a statistically significant correlation between MPA trough levels and AUC, this association was weak and accounted for only 30% of the variability in MPA trough levels. This relationship might be even more unreliable in men than women. The use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was associated with increased MPA trough levels and AUC at 0-4 h (AUC0-4)., Conclusion: Trough levels of MPA do not show a strong correlation with AUC. In clinical situations where MPA levels are essential to guide therapy, an AUC0-4 would be a better indicator of the adequacy of treatment.

Peripheral T-cell lymphomas (PTCL) are a group of rare malignancies characterized by chemotherapy resistance and poor prognosis. Romidepsin and pralatrexate were approved by the US Food and Drug Administration for patients with relapsed/refractory PTCL, exhibiting response rates of 25% and 29% respectively. Based on synergy in preclinical models of PTCL, we initiated a phase 1 study of pralatrexate plus romidepsin in patients with relapsed/refractory lymphoma. This was a single institution dose-escalation study of pralatrexate plus romidepsin designed to determine the dose-limiting toxicities (DLTs), maximum tolerated dose, pharmacokinetic profile, and response rates. Patients were treated with pralatrexate (10 to 25 mg/m 2 ) and romidepsin (12 to 14 mg/m 2 ) on 1 of 3 schedules: every week × 3 every 28 days, every week × 2 every 21 days, and every other week every 28 days. Treatment continued until progression, withdrawal of consent, or medical necessity. Twenty-nine patients were enrolled and evaluable for toxicity. Coadministration of pralatrexate and romidepsin was safe, well tolerated, with 3 DLTs across all schedules (grade 3 oral mucositis × 2; grade 4 sepsis × 1). The recommended phase 2 dose was defined as pralatrexate 25 mg/m 2 and romidepsin 12 mg/m 2 every other week. Twenty-three patients were evaluable for response. The overall response rate was 57% (13/23) across all patients and 71% (10/14) in PTCL. The phase 1 study of pralatrexate plus romidepsin resulted in a high response rate in patients with previously treated PTCL. A phase 2 study in PTCL will determine the efficacy of the combination. This trial was registered at www.clinicaltrials.gov as #NCT01947140., (© 2018 by The American Society of Hematology.)

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 (Fe 3 O 4 @SiO 2 /DABCO) by Au-S bond. The interactions of epirubicin with aptamer on the AuNPs/Fe 3 O 4 @SiO 2 /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/Fe 3 O 4 @SiO 2 /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., (Copyright © 2017 Elsevier B.V. All rights reserved.)

To achieve drug targeting and on-demand releasing, surface functionalization plays a critical role in fabricating potential mesoporous silica nanoparticles (MSNs) toward tumor chemotherapy. Here, we prepared a size-controllable ligand-functionalized MSNs delivery system via coordinate bonding, which can release doxorubicin (DOX) in response to pH and prolong the circulation time of drug in vivo. After modifying the external surface of MSNs with polyethylene glycol (PEG), iminodiacetic acid (IDA) as a ligand was mainly grafted on the surface of mesopores to chelate cupric iron and DOX in sequence via coordinate bonds. The modified MSNs exhibited a uniform size of about 72nm and could be stably dispersed in saline. After DOX loading, the drug loading content and encapsulation efficiency were calculated to be 9.3±0.1% and 92.8±0.6%, respectively. Moreover, the resultant MSNs showed a pH-responsive release property, which could avoid the premature leakage of drug in circulation and achieve on-demand release within the tumor cells. Additionally, the pharmacokinetic study in healthy rats demonstrated that DOX loaded in functionalized MSNs presented the longer circulation time and lower plasma clearance rate compared with DOX solution. These results indicated that PEG/IDA modified MSNs with pH-responsive release capacity possessed great promising as an anticancer drug delivery system., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Aims: The aims of the study were: (i) to characterize the pharmacokinetics (PK) of doxorubicin (DOX) and doxorubicinol (DOXol) in patients diagnosed with non-Hodgkin's lymphoma (NHL) using a population approach; (ii) to evaluate the influence of various covariates on the PK of DOX; and (iii) to evaluate the role of DOX and DOXol exposure in haematological toxicity., Methods: Population PK modelling (using NONMEM) was performed using DOX and DOXol plasma concentration-time data from 45 NHL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). The influence of drug exposure on haematological toxicity was analysed using the Mann-Whitney-Wilcoxon test., Results: A five-compartment model, three for DOX and two for DOXol, with first-order distribution and elimination for both entities best described the data. Population estimates for parent drug (CL) and metabolite (CL m ) clearance were 62 l h -1 and 27 l h -1 , respectively. The fraction metabolized to DOXol (F m ) was estimated at 0.22. While bilirubin and aspartate aminotransferase showed an influence on the CL and CL m , the objective function value decrease was not statistically significant. A trend towards an association between the total area under the concentration-time curve (AUC total ), the area under the concentration-time curve for DOX (AUC) plus the area under the concentration-time curve for DOXol (AUC m ), and the neutropenia grade (P = 0.068) and the neutrophil counts (P = 0.089) was observed, according to an exponential relationship., Conclusions: The PK of DOX and DOXol were well characterized by the model developed, which could be used as a helpful tool to optimize the dosage of this drug. The results suggest that the main active metabolite of DOX, DOXol, is involved in the haematological toxicity of the parent drug., (© 2016 The British Pharmacological Society.)

Congestive heart failure is one of the leading causes of disability in long-term survivors of cancer. The anthracycline antibiotic doxorubicin (DOX) is used to treat a variety of cancers, but its utility is limited by its cumulative cardiotoxicity. As advances in cancer treatment have decreased cancer mortality, DOX-induced cardiomyopathy has become an increasing problem. However, the current means to alleviate the cardiotoxicity of DOX are limited. We considered that vascular endothelial growth factor-B (VEGF-B), which promotes coronary arteriogenesis, physiological cardiac hypertrophy, and ischemia resistance, could be an interesting candidate for prevention of DOX-induced cardiotoxicity and congestive heart failure. To study this, we administered an adeno-associated viral vector expressing VEGF-B or control vector to normal and tumor-bearing mice 1 wk before DOX treatment, using doses mimicking the concentrations used in the clinics. VEGF-B treatment completely inhibited the DOX-induced cardiac atrophy and whole-body wasting. VEGF-B also prevented capillary rarefaction in the heart and improved endothelial function in DOX-treated mice. VEGF-B also protected cultured endothelial cells from apoptosis and restored their tube formation. VEGF-B increased left ventricular volume without compromising cardiac function, reduced the expression of genes associated with pathological remodeling, and improved cardiac mitochondrial respiration. Importantly, VEGF-B did not affect serum or tissue concentrations of DOX or augment tumor growth. By inhibiting DOX-induced endothelial damage, VEGF-B could provide a novel therapeutic possibility for the prevention of chemotherapy-associated cardiotoxicity in cancer patients., Competing Interests: The authors declare no conflict of interest.

We describe a highly sensitive nanoparticle-based fluorescence resonance energy transfer (FRET) probe developed without using molecular fluorophores as donors and acceptors. The success of this work relies on the strategy that DNA scission was designed to occur to the probe when target presented, which enabled the fluorescence signal "turn-on" of graphene quantum dots (GQDs) and thus quantitative analysis. In particular, amino-modified SiO2 NPs were initially coated by GQDs to form highly emitting SiO2/GQDs, followed by conjunction with DNA functionalized gold nanoparticles (Au NPs-DNA) to form SiO2/GQDs-DNA-Au NPs composite. Owing to the FRET interactions between the GQDs and Au NPs, the fluorescence of GQDs was effectively quenched by Au NPs. When bleomycin (BLM), a model analyte, was mixed with the probe, the fluorescence signal of GQDs would be restored due to the removal of Au NPs from the SiO2/GQDs surface by DNA scission treatment with BLM in the presence of Fe (II). The current FRET probe shows a good linear relationship between the fluorescence intensity and the concentration of BLM in the range from 0.5nM to 1μM with a detection limit of 0.2nM. The probe also shows satisfactory results for the analysis of clinical serum samples. This method provides versatility to the application of GQDs in FRET biosensing and could be potentially extended to other similar systems by replacing the linker between the GQDs and Au NPs., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Aims: The aim of the present study was to develop a pharmacokinetic-pharmacodynamic (PK-PD) model to characterize the relationship between plasma doxorubicin and N-terminal pro B-type natriuretic peptide (NT-proBNP) concentrations within 48 h of doxorubicin treatment., Methods: The study enrolled 17 female patients with stages 1-3 breast cancer and receiving adjuvant doxorubicin (60 mg m(-2) ) and cyclophosphamide (600 mg m(-2) ) every 14 days for four cycles. In two consecutive cycles, plasma concentrations of doxorubicin, doxorubicinol, troponin and NT-proBNP were collected before infusion, and up to 48 h after the end of doxorubicin infusion. Nonlinear mixed-effects modelling was used to describe the PK-PD relationship of doxorubicin and NT-proBNP., Results: A three-compartment parent drug with a one-compartment metabolite model best described the PK of doxorubicin and doxorubicinol. Troponin concentrations remained similar to baseline. An indirect PD model with transit compartments best described the relationship of doxorubicin exposure and acute NT-proBNP response. Estimated PD parameters were associated with large between-subject variability (total assay variability 38.8-73.9%). Patient clinical factors, including the use of enalapril, were not observed to be significantly associated with doxorubicin PK or NT-proBNP PD variability., Conclusion: The relationship between doxorubicin concentration and the acute NT-proBNP response was successfully described with a population PK-PD model. This model will serve as a valuable framework for future studies to identify clinical factors associated with the acute response to doxorubicin. Future studies are warranted to examine the relationship between this acute response and subsequent heart failure. Should such a relationship be established, this model could provide useful information on patients' susceptibility to doxorubicin-induced long-term cardiotoxicity., (© 2016 The British Pharmacological Society.)

Doxorubicin (Dox) is a DNA-targeting anthracycline antibiotic active against a wide spectrum of cancers. The interaction between Dox and double-stranded DNA (dsDNA) was used to load Dox using DNA duplexes as carriers. More importantly, the interesting DNA sequence-dependent fluorescence response of Dox could be exploited in the design of efficient Dox release systems and efficient fluorescence sensors. In this work, we demonstrated that separate introduction of G and C bases into T-rich single-stranded DNA (ssDNA) sequences afforded the best discrimination of Dox binding between dsDNA and ssDNA. For the first time, we successfully utilized this interesting DNA sequence-dependent fluorescence response of Dox as a signal transduction mechanism for the sensitive detection of biothiols in human serum. Cysteine, homocysteine, and glutathione were detected at as low as 26 nM, 37 nM, and 29 nM, respectively. The biosensors exhibited not only good selectivity, stability, and sensitivity in aqueous solutions but also a sensitive response in human serum, demonstrating their potential for diagnosis.

Context: Doxorubicin (DOX)-loaded folate-targeted poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) [P(HB-HO)] nanoparticles [DOX/FA-PEG-P(HB-HO) NPs] were prepared by the W1/O/W2 solvent extraction/evaporation method for applications in cancer treatment. However, the biodistribution, pharmacokinetics, and targeting of the nanoparticles (NPs) have not yet been studied., Objective: The biodistribution, pharmacokinetics, and targeting of DOX/FA-PEG-P(HB-HO) NPs were evaluated in female BALB/c nude mice bearing HeLa tumors., Materials and Methods: Three DOX formulations were injected into the tail vein of the mice at a dosage of 5 mg/kg. At each time point, blood and various tissues were collected. All samples were then processed and analyzed by a validated high performance liquid chromatographic (HPLC) method., Results: The t1/2 values of DOX/P(HB-HO) NPs and DOX/FA-PEG-P(HB-HO) NPs were 2.7- and 3.5-times higher than that of free DOX. No significant difference (p > 0.05) was found in Cmax between the NPs and free DOX. The Tmax values of the two NPs were prolonged from 0.25 to 1 h. The AUC0-t values were 1.55- and 3.05-folds higher than that of free DOX, and MRT increased to 15.99 h for DOX/P(HB-HO) NPs and 25.14 h for DOX/FA-PEG-P(HB-HO) NPs. For DOX/FA-PEG-P(HB-HO) NPs, the DOX content in the tumors were 10.81- and 3.33-times higher than those for free DOX and DOX/P(HB-HO) NPs at 48 h, respectively., Discussion and Conclusions: DOX/FA-PEG-P(HB-HO) NPs displayed reduced cardiac toxicity and improved bioavailability. Moreover, the NPs exhibited a significant extent of DOX accumulation in the tumors, thus suggesting that folate-targeted NPs could effectively transport into HeLa tumors with satisfying targeting.

In this study, long-circulating Arg-Gly-Asp (RGD)-modified aclacinomycin A (ACM) liposomes were prepared by thin film hydration method. Their morphology, particle size, encapsulation efficiency, and in vitro release were investigated. The RGD-ACM liposomes was about 160 nm in size and had the visual appearance of a yellowish suspension. The zeta potential was -22.2 mV and the encapsulation efficiency was more than 93%. The drug-release behavior of the RGD-ACM liposomes showed a biphasic pattern, with an initial burst release and followed by sustained release at a constant rate. After being dissolved in phosphate-buffered saline (pH 7.4) and kept at 4°C for one month, the liposomes did not aggregate and still had the appearance of a milky white colloidal solution. In a pharmacokinetic study, rats treated with RGD-ACM liposomes showed slightly higher plasma concentrations than those treated with ACM liposomes. Maximum plasma concentrations of RGD-ACM liposomes and ACM liposomes were 4,532 and 3,425 ng/mL, respectively. RGD-ACM liposomes had a higher AUC0-∞ (1.54-fold), mean residence time (2.09-fold), and elimination half-life (1.2-fold) when compared with ACM liposomes. In an in vivo study in mice, both types of liposomes inhibited growth of human lung adenocarcinoma (A549) cells and markedly decreased tumor size when compared with the control group. There were no obvious pathological tissue changes in any of the treatment groups. Our results indicate that RGD-modified ACM liposomes have a better antitumor effect in vivo than their unmodified counterparts.

Ovarian cancer is the fifth most common malignancy in the world's female population and with the highest lethality index among gynecological tumors. The prognosis of metastatic disease is usually poor, especially in platinum-resistant cases. There are several options for the treatment of metastatic disease resistant to platinum derivates (e.g. paclitaxel, topotecan and pegylated liposomal doxorubicin), all of which are considered equipotent. Pegylated liposomal doxorubicin (PLD) is a liposomal form of the anthracycline antibiotic doxorubicin. It is characterized by more convenient pharmacokinetics and a different toxicity profile. Cardiotoxicity, the major adverse effect of conventional doxorubicin, is reduced in PLD as well as hematotoxicity, alopecia, nausea and vomiting. Skin toxicity and mucositis, however, emerge as serious issues since they represent dose and schedule-limiting toxicities. The pharmacokinetics of PLD (prolonged biological half-life and preferential distribution into tumor tissue) provide new possibilities to address these toxicity issues. The extracorporeal elimination of circulating liposomes after PLD saturation in the tumor tissue represents a novel and potent strategy to diminish drug toxicity. This article intends to review PLD characteristics and the importance of extracorporeal elimination to enhance treatment tolerance and benefits.

In many studies for chemoembolization of hepatocellular carcinoma, the Lipiodol emulsion preparation protocols, especially the mixing steps, were unclear or even unrevealed at all. However, doxorubicin (DOX) release may depend on the composition and volume ratio (Lipiodol to DOX solution) of a Lipiodol emulsion. Therefore, we conducted a preclinical study to compare in-vitro drug release and in-vivo pharmacokinetics of DOX from diverse Lipiodol emulsions and drug-eluting beads (DEBs) and to compare the tumor response in a rabbit VX2 carcinoma model. DOX release profiles of four types of Lipiodol emulsions with different media (normal saline or Pamiray as an iodinated contrast medium), volume ratio (Lipiodol to DOX solution), and DEBs were investigated in-vitro. For the in-vivo study, 15 rabbits bearing VX2 carcinoma in the liver were treated with 4∶1 volume ratio Lipiodol emulsion (group A), 1∶1 volume ratio Lipiodol emulsion (group B), and DEBs (group C) chemoembolization. Blood and tissue sampling was conducted to evaluate DOX concentration in plasma and tissues, histological changes, and liver toxicity. The most stable emulsion was formed with Pamiray (including DOX) at a 4∶1 volume ratio. The AUC value of group A was significantly lower than that of group B (p = 0.003) but comparable to that of group C (p = 0.071). The Cmax value of group A was significantly different compared with those of group B (p = 0.004) and C (p = 0.015). The tissue drug concentration in group A was comparable to that in group C (p = 0.251). No viable tumor was detected in rabbits of group A and B. In group C, viable tumor less than 10% was seen in two of the five rabbits. There were no significant differences in liver enzyme levels after the procedure. In conclusion, DOX release and pharmacokinetics of presented emulsion systems depend substantially on their composition. Therefore, Lipiodol emulsion type should be considered when interpreting data and designing new studies dealing with chemoembolization.

Local drug delivery depots have significant clinical utility, but there is currently no noninvasive technique to refill these systems once their payload is exhausted. Inspired by the ability of nanotherapeutics to target specific tissues, we hypothesized that blood-borne drug payloads could be modified to home to and refill hydrogel drug delivery systems. To address this possibility, hydrogels were modified with oligodeoxynucleotides (ODNs) that provide a target for drug payloads in the form of free alginate strands carrying complementary ODNs. Coupling ODNs to alginate strands led to specific binding to complementary-ODN-carrying alginate gels in vitro and to injected gels in vivo. When coupled to a drug payload, sequence-targeted refilling of a delivery depot consisting of intratumor hydrogels completely abrogated tumor growth. These results suggest a new paradigm for nanotherapeutic drug delivery, and this concept is expected to have applications in refilling drug depots in cancer therapy, wound healing, and drug-eluting vascular grafts and stents.

Hypothesis: Liposomes made of single-chain amphiphiles and a large amount of sterols display several advantages including a limited permeability. In the present paper, we examine the possibility to prepare such non-phospholipid liposomes with interfacial polyethylene glycol (PEG) in order to improve their circulation in the blood stream. Cholesterol (Chol) was chosen as the PEG anchor., Experiments: The phase behavior of mixtures of palmitic acid (PA) and cholesterol including various proportions of PEGylated cholesterol (PEG-Chol) was characterized. In conditions leading to the formation of fluid bilayers, properties of the resulting liposomes were assessed., Findings: Up to 20 mol% of PEGylated cholesterol could be introduced without significant perturbations in fluid bilayers made of PA and cholesterol. With 10 mol% PEG-Chol, PA/Chol/PEG-Chol liposomes showed a very limited permeability to calcein and doxorubicin. Doxorubicin could be actively loaded in PA/Chol/PEG-Chol liposomes with a high drug loading efficiency and a high drug to lipid ratio. Pharmaco-kinetic experiments in rats indicated that interfacial PEG reduced the clearance of PA/Chol liposomes compared to the naked ones. However the lifetime of these non-phospholipid liposomes in the blood circulation was considerably shorter than that observed for control PEGylated phospholipid liposomes, a phenomenon associated with the negative interfacial charge of the PA/Chol/PEG-Chol liposomes., (Copyright © 2014 Elsevier Inc. All rights reserved.)

In this work, stainless steel (SS) was used as a substrate to fabricate an inexpensive and disposable impedimetric immunosensor. SS surface was modified with a stable thin layer of 3-aminopropyltriethoxysilane (APTES), and followed by electrodeposition of gold nanoparticles (GNPs). The morphology and size of the electrodeposited GNPs were studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The interfacial properties of the SS electrode after each modification step were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a solution containing [Fe(CN)₆]³⁻/⁴⁻ as a redox probe. The results indicated that APTES layer was successfully formed on the electrode surface and GNPs enhanced the conductivity and sensitivity of the electrode. The applicability of the proposed assembled electrode in electrochemical immunosensors was followed by immobilizing doxorubicin-specific monoclonal antibodies onto the GNP-modified electrode to determine doxorubicin concentration using the EIS technique. The relative charge transfer resistance was found to increase linearly with doxorubicin concentration in two ranges from 2.5 to 30.0 and 30.0 to 100.0 pg mL⁻¹. The detection limit of the immunosensor was 1.7 pg mL⁻¹ (3s(b)/m) doxorubicin. The satisfactory results were obtained from determination of doxorubicin concentrations in spiked human serum samples. The recoveries were in the range of 88.0-122.2%. These results indicate that modified SS electrodes are promising sensing elements to construct economical electrochemical immunosensors for routine quantitative analyses., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this work, we present the development of a method for the determination of doxorubicin in plasma samples in the presence of an unexpected component (riboflavin) by using total synchronous fluorescence spectroscopic data matrices. To the best of our knowledge, this is the first time that the second-order advantage is obtained with this kind of data. Two strategies including unfolding the data and: (a) processing with multivariate curve resolution coupled to alternating least-squares as first-order data or (b) processing with unfolded partial least-squares and exploiting the second-order advantage by the residual bilinearization procedure were considered. The calibration set was built with human plasma samples spiked with doxorubicin, while the validation set was prepared with human plasma samples spiked with both doxorubicin and riboflavin, a drug whose spectrum highly overlaps with the one corresponding to doxorubicin. Both methodologies reached good indicators of accuracy: recoveries of ca. 100 ± 8% and REP of ca. 5%; and precision: coefficient of variations between 7 and 9%.

Background: Intraperitoneal carcinmatosis and intra-abdominal tumour cell dissemination may occur with several tumour entities. At this final stage of the tumour disease, systemic chemotherapy remains only palliative and may be accompanied by severe side-effects. Alternatively, compartment-based therapy by intraperitoneal (i.p.) instillation of doxorubicin drug-eluting beads (dox-DEB) has been proposed. Here we investigated the safety, pharmacokinetics and side-effects of i.p. dox-DEB in a large animal trial., Materials and Methods: Ten black-headed meat-sheep received i.p. polyvinyl-alcohol-encapsulated doxorubicin. The plasma concentration of doxorubicin, blood count and laboratory findings were recorded and histological examination of the organs was performed., Results: After i.p. instillation, elevated serum levels of doxorubicin were obtained. After this initial phase, serum levels remained constant. Upon autopsy, no signs of systemic toxicity were detected. Beads remained within the peritoneal cavity and were not systemically distributed. However, we found significant local toxicity in five sheep, three of which died due to severe peritonitis., Conclusion: Doxorubicin can be successfully targeted to the peritoneal cavity by bead encapsulation. Local toxic effects must be controlled in order to facilitate clinical utility.

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., (Copyright © 2011. Published by Elsevier B.V.)

Neutral liposomes (NLP) exhibit preferential localization in solid tumors based on the enhanced permeation and retention (EPR) effect. Cationic liposomes (CLP) have a propensity for localizing in newly formed tumor vessels and they have a potentially enhanced antitumor effect. However, an increased amount of cationic lipids in liposomes also induces aggregation through electrostatic interactions between the liposomes and the anionic species in the circulation, which results in a reduced EPR effect. Consequently, it is important to investigate the characteristics of liposomes with different surface potentials in vitro to achieve an optimal intratumoral distribution and antitumor effect in vivo. In this study, the authors evaluated the characteristics of doxorubicin (DOX)-loaded NLPs, CLPs, polyethylene glycol (PEG)-modified NLPs (NLP-PEG), and PEGylated CLPs (CLP-PEG) (ie, encapsulation efficacy, zeta potential, size, membrane fluidity, aggregation in serum, and uptake of liposomes into rat aortic endothelial cells (RAECs)) to further understand their influences on the pharmacokinetics, biodistribution, and antitumor therapy in vivo. The results showed that increased amounts of cationic lipids resulted in severe liposome aggregation in the presence of serum, yet it did not alter the membrane fluidity to a large extent. The uptake of liposomes into RAECs, visualized by confocal fluorescence microscopy, confirmed the rapid uptake of CLP by the endothelial cells compared with NLP. However, the pharmacokinetics, biodistribution and anticancer efficacies of these liposomes in vivo revealed that the CLP with highly positive surface potentials exhibited reduced circulation times and poor distribution in tumors. The NLP-PEG exhibited the highest anticancer efficacy; CLP-PEG, the second highest; and CLP with the most positive surface potential, the lowest. These phenomena were mostly due to the rapid aggregation in serum and subsequent accumulation in the lungs upon the intravenous injection of the CLP. Caution should be exercised when chemotherapeutic drugs are loaded into CLP for tumor therapy.

The present study aimed to identify polymorphic genes encoding carbonyl reductases (CBR1, CBR3) and investigate their influence on doxorubicin disposition in Asian breast cancer patients (n = 62). Doxorubicin (60 mg/m(2)) was administered every 3 weeks for four to six cycles and the pharmacokinetic parameters were estimated using non-compartmental analysis (WinNonlin). The Mann-Whitney U-test was used to assess genotypic-phenotypic correlations. Five CBR1 (-48G>A, c.219G>C, c.627C>T, c.693G>A, +967G>A) and CBR3 (c.11G>A, c.255C>T, c.279C>T, c.606G>A, c.730G>A) polymorphisms were identified. The CBR1 D2 diplotypes were characterized by the presence of at least one variant allele at the c.627C>T and +967G>A loci. Patients in the CBR1 D1 diplotype group had significantly higher clearance (CL) normalized to body surface area (BSA) (CL/BSA[L/h/m(2)]: median 25.09; range 16.44-55.66) and significantly lower exposure levels; area under curve (AUC(0-infinity)/dose/BSA [h/m(5)]; median 15.08; range 6.18-38.03) of doxorubicin compared with patients belonging to the CBR1 D2 diplotype group (CL/BSA[L/h/m(2)]; median 20.88; range 8.68-31.79, P = 0.014; and AUC(0-infinity)/dose/BSA[h/m(5)]; median 21.35; range 9.82-67.17, P = 0.007 respectively). No significant influence of CBR3 polymorphisms on the pharmacokinetics of doxorubicin were observed in Asian cancer patients. The present exploratory study shows that CBR1 D2 diplotypes correlate with significantly higher exposure levels of doxorubicin, suggesting the possibility of lowered intracellular conversion to doxorubicinol in these patients. Further evaluation of carbonyl reductase polymorphisms in influencing the treatment efficacy of doxorubicin-based chemotherapy in Asian cancer patients are warranted.

The aim of this study was to evaluate the plasma trough concentrations (C(0)) of mycophenolic acid (MPA) and its major metabolite MPA 7-O-glucuronide (MPAG) in metal cation (MC)(-) (non-treated) and MC(+) (co-treated) patients who received tacrolimus (Tac) or cyclosporine (CyA). Fifty-nine Japanese stable kidney transplant recipients receiving immunosuppressive regimens containing mycophenolate mofetil (MMF) and a calcineurin inhibitor (CNI) were included in this study. Seven in the 25 patients receiving Tac and 8 in the 34 patients receiving CyA were treated with concomitant MCs administration. Multiple regression analysis revealed that concomitant MCs and CyA administration influenced MPA C(0). Their standardized partial regression coefficients were -0.29 and -0.41, respectively. Stratified analysis based on CNI treatment revealed that MPA C(0) decreased significantly by 56% with concomitant MCs administration in Tac-treated patients. There was no significant difference in MPA C(0) between the MC(-) and MC(+) groups in CyA-treated patients. With respect to MPAG C(0), MC(+) group tended to be lower by 26% than MC(-) group in Tac-treated patients. There was no significant difference in MPAG C(0) between the MC(-) and MC(+) groups in CyA-treated patients. Concomitant MCs administration did not affect the C(0) ratio of MPAG to MPA in either Tac- or CyA-treated patients. In conclusion, MCs co-administration decrease MPA C(0) in patients receiving Tac and may cause lower MPA exposure. There are little pharmacokinetic interactions between MMF and concomitant MCs in CyA-treated patients.

A specific, simple and sensitive HPLC method with UV detection was developed and validated for the pharmacokinetic studies of indirubin in rat plasma for the first time. Indirubin, with osthole as the internal standard, was extracted from plasma samples by liquid-liquid extraction. Chromatographic separation was conducted on a reverse-phase ODS column (200 mm x 4.6 mm, i.d., 5 microm), using a mixture of methanol-water (75:25, v/v) as the mobile phase at a flow rate of 1.0 ml/min with UV detection at 289 nm. The calibration curve of indirubin was linear over the range of 6.5-1950 ng/ml in rat plasma. The lower limit of quantification (LLOQ) was found to be 6.5 ng/ml. The present method was successfully applied for estimating the pharmacokinetic parameters of indirubin following intravenous and intraperitoneal administration of indirubin to rats.

In wild-type mice, a single injection of streptozotocin (STZ, 200 mg/kg body wt) caused within 4 days severe hyperglycemia, hypoinsulinemia, significant glucose intolerance, loss of body weight, and the disappearance of pancreatic beta-cells. However, in ATP-sensitive K(+) channel (K(ATP) channel)-deficient mice (Kir6.2(-/-) mice), STZ had none of these effects. Exposing isolated pancreatic islets to STZ caused severe damage in wild-type but not in Kir6.2(-/-) islets. Following a single injection, plasma STZ levels were slightly less in Kir6.2(-/-) mice than in wild-type mice. Despite the difference in plasma STZ, wild-type and Kir6.2(-/-) liver accumulated the same amount of STZ, whereas Kir6.2(-/-) pancreas accumulated 4.1-fold less STZ than wild-type pancreas. Kir6.2(-/-) isolated pancreatic islets also transported less glucose than wild-type ones. Quantification of glucose transporter 2 (GLUT2) protein content by Western blot using an antibody with an epitope in the extracellular loop showed no significant difference in GLUT2 content between wild-type and Kir6.2(-/-) pancreatic islets. However, visualization by immunofluorescence with the same antibody gave rise to 32% less fluorescence in Kir6.2(-/-) pancreatic islets. The fluorescence intensity using another antibody, with an epitope in the COOH terminus, was 5.6 times less in Kir6.2(-/-) than in wild-type pancreatic islets. We conclude that 1) Kir6.2(-/-) mice are STZ resistant because of a decrease in STZ transport by GLUT2 in pancreatic beta-cells and 2) the decreased transport is due to a downregulation of GLUT2 activity involving an effect at the COOH terminus.

Background: The purpose of the study was to characterize the pharmacokinetics of mycophenolic acid (MPA) in Japanese heart transplant recipients and to find the time point that has the best correlation with the MPA area under the plasma concentration curve (AUC)., Methods and Results: Twenty-two Japanese recipients treated with mycophenolate mofetil were evaluated in the study. Approximately 9 months after transplantation, the area under the MPA serum concentration-time curve from 0 to 12 h (AUC(0-12 h)) was evaluated. The MPA AUC(0-12 h) h values in the cyclosporine (CsA) and tacrolimus (FK) groups ranged from 13.11 to 50.98 mug . h/ml and from 39.19 to 93.18 mug . h/ml, respectively. Fourteen models were developed and analyzed for their ability to estimate the MPA AUC(0-12 h) based on a limited number of samples in the CsA group. Sixteen models were developed in the FK group. The best model for predicting the full MPA AUC(0-12 h) in the CsA group was a 3-time-point model that included C(0 h), C(1 h) and C(2 h) (r(2), 0.96; mean prediction error, 0.15+/-7.85%); a 2-time-point model that included C(0 h), and C(2 h) (r(2), 0.94; mean prediction error, 0.495+/-10.35%) was also reliable. In the FK group, a 3-time-point model that included C(1 h), C(2 h) and C(4h) (r(2), 0.73; mean prediction error, 2.73+/-17.09%) was the best model for predicting the full MPA AUC(0-12 h), but it was not reliable in clinical practice., Conclusion: A 3-(C(0 h), C(1 h) and C(2 h)) and a 2-time-point model (C(0 h) and C(2 h)) are useful for predicting the full MPA AUC(0-12 h) in Japanese heart transplant recipients treated with CsA but not with FK.

Daunorubicin (DNR) is a significant antineoplastic antibiotic, which is usually applied to a chemotherapy of acute lymphatic and myelogenous leukaemia. Unfortunately, cardiotoxicity research in animals has indicated that DNR is cardiotoxic. Therefore, it is important to quantify DNR in biological fluids. A new algorithm, the alternating fitting residue (AFR) method, and the traditional parallel factor analysis (PARAFAC) have been utilized to directly determine DNR in human plasma and urine. These methodologies fully exploit the second-order advantage of the employed three-way fluorescence data, allowing the analyte concentrations to be quantified even in the presence of unknown fluorescent interferents. Furthermore, in contrast to PARAFAC, more satisfactory results were gained with AFR.

Purpose: The incorporation of doxorubicin in long-circulating sterically stabilized liposomes (SSL-DXR) alters the pharmacokinetics and biodistribution of doxorubicin and therefore has the potential to alter the pharmacologic properties of doxorubicin. Previously, we showed that repetitive administration of SSL-DXR alters tumor vascular permeability., Experimental Design: Here, we investigated the effect of weekly i.v. injections of SSL-DXR on plasma pharmacokinetics and drug biodistribution in the orthotopic 9L rat brain tumor model., Results and Conclusions: The pharmacokinetics of free doxorubicin (5.67 mg/kg) did not change with repeat dosing. In contrast, drug concentrations in plasma and brain tumor increased and deposition in liver and spleen decreased after administration of the second of two weekly doses of SSL-DXR. Noncompartmental analysis and descriptive pharmacokinetic models were created to test hypotheses relating to the mechanisms responsible for alterations in SSL-DXR deposition. The analysis suggested that weekly administration of SSL-DXR significantly (P < 0.05) decreased the plasma elimination rate of SSL-DXR (34%) and decreased drug deposition in liver (2-fold) and spleen (3.5-fold). The pharmacokinetic model that best captured the observed 2.5-fold increase in tumor uptake of SSL-DXR mediated by repeat dosing was one that hypothesized that the rates of drug influx/efflux into tumor were increased by the first dose of SSL-DXR. Models that accounted only for residual drug deposited in the tissue or blood by the first weekly injection provided inferior fits to the data. Thus, the effects of repetitive dosing on SSL-DXR deposition in tumor are consistent with a treatment-mediated alteration of tumor vascular permeability.

The underlying primary damage to the seminiferous epithelium caused by chemotherapeutic regimens at childhood is largely unknown. The present investigation was designed to identify acute cytotoxic events in the testis caused by a single dose of doxorubicin. Male rats at 6, 16, and 24 days of age were injected with doxorubicin (3 mg/kg, i.p.) or vehicle (saline) alone and 24 and 48 hours later, the germ cell types and apoptotic cells in the seminiferous epithelium were examined. As indicated by microscopy and terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling staining, an 8-fold increase in the number of apoptotic germ cells in the testes of 6-day-old rats was observed 48 hours after doxorubicin treatment. Spermatogonia migrating to the basement membrane were the primary cell type undergoing this induced apoptosis. A single dose of amifostine (200 mg/kg) administered i.p. 15 minutes before injection of doxorubicin provided no protection against this enhanced apoptosis. Under the same conditions, testicular levels of p53 and activated caspase 8 were elevated, whereas the level of murine double minute-2 was lowered. In contrast, doxorubicin treatment did not result in any significant change in the physiologic, stage-specific germ cell apoptosis occurring in the testes of 16- and 24-day-old rats. These observations suggest that the initiation phase of spermatogenesis is highly sensitive to doxorubicin-induced apoptosis. Gonocytes and early spermatogonia are the cell types that are vulnerable to this p53-trigged apoptosis, which results in a decrease in the size of the pool of germ-line stem cells. Amifostine fails to protect the germ cells against this cytotoxic insult.

A rapid and sensitive high performance liquid chromatographic (HPLC) assay utilizing fluorimetric detection (excitation at 480 nm, emission at 560 nm) for the determination of doxorubicin in dog blood was developed and validated. Treatment of blood samples containing doxorubicin with AgNO3 (as protein precipitant) resulted in appearance of an additional peak in the chromatogram of doxorubicin at 11.5 min along with the parent peak (tR = 5.5 min). The latter peak was not found when treated with other protein precipitants such as trichloroacetic acid and methanol. Construction of a calibration curve based on the area of the first peak alone did not result in linearity of the curve. However, summation of areas of both peaks resulted in a curve with good linearity and coefficient of determination (R2 = 0.9985). Appearance of the second peak may be due to the interaction of doxorubicin with cellular components of blood in the presence of AgNO3 leading to the formation of a complex with reduced polarity. Analysis of the quality control samples showed good accuracy (96.7-100.42) and precision (RSD = 2.6-5.7%). The proposed method could be advantageous in estimation of doxorubicin incorporated into targeted delivery systems that concentrate in blood cells and quantify the absolute blood concentration of doxorubicin.

Aims: To investigate the population pharmacokinetics of daunorubicin in children after administration of liposomal daunorubicin (Daunoxome)., Methods: Plasma samples from 19 children with relapsed acute myeloic leukaemia and five children with other malignancies were collected. Daunoxome was administered as a 1- to 2.5 h infusion with doses ranging from 30 to 60 mg m(-2). Overall, 214 samples were analysed for daunorubicin using capillary electrophoresis, and population pharmacokinetic modelling was performed using NONMEM., Results: The data were best described by a one compartment model. Inclusion of interoccasion variability in the model (16.7% for clearance) improved strongly the precision of the estimates. The inclusion of body surface area or height as a covariate decreased interindividual variability. However, the best fit was obtained using the absolute dose, and when weight was included as a covariate for clearance (CL) and volume of distribution (V ). The final parameter estimates were: CL 6.41 ml h(-1) kg(-1) +/- 0.5 51% and V 65.4 ml kg(-1) +/- 0.5 27% (population mean +/- 0.5 interindividual variability). The area under the curve at a dose of 60 mg m(-2) was 231 mg l (-1)h., Conclusions: In comparison with free daunorubicin, Daunoxome shows a low volume of distribution, a lower clearance and a lower interindividual variability in these parameters. This might be advantageous in reducing the variability in exposure to the drug.

Background and Objective: Pharmacologic studies on blasts from patients with leukemia are generally performed on density gradient isolated blood or bone marrow cells. Thereby, cellular drug accumulation and efflux are determined as mean values of the entire cell population. The objective of the present study was to characterize the heterogeneity in the accumulation and efflux of daunorubicin in various subpopulations of mononuclear cells isolated from patients with acute myeloid leukemia (AML)., Design and Methods: Mononuclear cells from 33 patients with AML were isolated from peripheral blood by density gradient centrifugation on Lymphoprep (1. 077 g/mL). Cellular accumulation of fluorescent daunorubicin was determined by flow cytometry after incubation of the cells at +37C for 1 hour. Thereafter, the cells were washed and reincubated in drug-free medium. Kinetics of drug efflux were determined by frequent determination of cellular fluorescence during 30 min. Daunorubicin accumulation and efflux were compared in the total isolated mononuclear cell population and in the various blast cell populations gated on FSC/SSC according to the results of immunophenotyping., Results: In 8 of these 33 (24%) patient samples, two distinct blast cell populations could be identified. In 7 out of 8 these cases the more immature blasts had a lower drug accumulation and in 6 out of the 8 cases also a higher efflux rate than the differentiating cell population. Cyclosporin A increased daunorubicin accumulation and reduced efflux in the immature blast population. In the differentiating cell population cyclosporin A increased both the accumulation and the efflux. In patients with a single blast cell population, the gated blast cells had a significantly lower drug accumulation but also a lower drug efflux rate than the total cell population., Interpretation and Conclusions: The results imply that drug transport studies on cells isolated from patients with AML give somewhat different results depending on the cell population studied. Some, but not all, of these differences in daunorubicin accumulation and efflux as well as in the effect of cyclo-sporin A can be explained by a heterogenous expression of the mdr1-gene. The observed heterogeneity may be of special relevance with regard to drug resistance. The presence of even a small resistant cell clone may jeopardize the effect of the chemotherapy due to expansion resulting in relapse of disease.

The present study investigated the effect of curcumin on adriamycin (ADR) nephrosis in rats. The results indicate that ADR-induced kidney injury was remarkably prevented by treatment with curcumin. Treatment with curcumin markedly protected against ADR-induced proteinuria, albuminuria, hypoalbuminaemia and hyperlipidaemia. Similarly, curcumin inhibited ADR-induced increase in urinary excretion of N-acetyl-beta-D-glucosaminidase (a marker of renal tubular injury), fibronectin and glycosaminoglycan and plasma cholesterol. Curcumin restored renal function in ADR rats, as judged by the increase in GFR. The data also demonstrated that curcumin protected against ADR-induced renal injury by suppressing oxidative stress and increasing kidney glutathione content and glutathione peroxidase activity. In like manner, curcumin abolished ADR-stimulated kidney microsomal and mitochondrial lipid peroxidation. These data suggest that administration of curcumin is a promising approach in the treatment of nephrosis caused by ADR.

A Phase I study of angiogenesis inhibitor TNP-470 was conducted in patients with advanced cancer. TNP-470 (25-235 mg/m2) was administered i.v. over 4 h once a week to patients who had solid tumors refractory to the best available treatment or with a high risk of recurrence and who had normal renal, hepatic, and hematological function and no evidence of coagulopathy. The aims of the study were to determine the maximum tolerated dose, dose-limiting toxicities (DLTs), and the pharmacokinetics of TNP-470 given on a once-weekly schedule. Thirty-six patients, ages 23-75 (median, 54 years), with an Eastern Cooperative Oncology Group performance status of 0-2 were treated. The number of patients at each dose level (mg/m2) were 6 (25), 3 (50), 3 (75), 3 (100), 3 (133), 12 (177), and 6 (235). The principal toxicities of TNP-470 were dizziness, lightheadedness, vertigo, ataxia, decrease in concentration and short-term memory, confusion, anxiety, and depression, which occurred at doses of 133, 177, and 235 mg/m2. Two patients treated at 235 mg/m2 experienced DLT in the form of grade III cerebellar neurotoxicity after 6 weeks of treatment. Overall, these neurological symptoms were dose-related, had an insidious onset, progressively worsened with treatment, and resolved completely within 2 weeks of stopping the drug. One patient with malignant melanoma had stabilization of the previously growing disease for 27 weeks while on the treatment. Two patients, one with adenocarcinoma of the colon and the other with a soft tissue sarcoma, had no clinically detectable disease but were at high risk for recurrence at the initiation of treatment and received 13 months and > 3 years of treatment, respectively, with no evidence of disease recurrence. The remaining patients had progression of their disease after 1-6 months of treatment. The mean plasma half-life (t(1/2)) of TNP-470 and its principal metabolite, AGM-1883, were extremely short (harmonic mean, t(1/2) of 2 and 6 min, respectively) with practically no drug detectable in the plasma by 60 min after the end of the infusion. MII, an inactive metabolite, had a considerably longer t(1/2) of approximately 2.6 h. Mean peak TNP-470 concentrations were > or = 400 ng/ml at doses > or = 177 mg/m2. On the basis of this study, the maximum tolerated dose of TNP-470 administered on a weekly schedule was 177 mg/m2 given i.v over 4 h. The principal DLT was neurotoxicity, which appeared to be dose-related and was completely reversible. On the basis of the short plasma t(1/2) of TNP-470, exploration of a prolonged i.v. infusion schedule is warranted.

Background: Different modalities of cytostatic lung perfusion were compared regarding plasma and tissue drug concentrations to assess the efficacy of an endovascular blood flow occlusion technique., Methods: A cytostatic lung perfusion study with doxorubicin hydrochloride was performed on large white pigs (n = 12). Plasma and tissue concentrations of doxorubicin were compared for isolated lung perfusion with open cannulation (ILP), blood flow occlusion perfusion with open cannulation of the pulmonary artery alone (BFO), and intravenous drug administration (i.v.). In a fourth group, thoracotomy-free BFO perfusion was performed by endovascular balloon catheterization of the pulmonary artery (endovascular BFO). The 3 animals in this group were used to compare the doxorubicin-perfused pulmonary tissue with the contralateral nonperfused lobes after 1 month., Results: The mean lung tissue doxorubicin concentration at the end of perfusion was 19.8 +/- 1.6 microg/g after ILP, 27.6 +/- 2.2 microg/g after BFO (p = not significant), and 3.0 +/- 0.8 microg/g after i.v. perfusion (p < 0.01). Whereas doxorubicin was not detectable in the plasma in the ILP group, concentrations ranged from not detectable to 0.44 microg/mL in the BFO group and from 0.31 to 0.84 microg/mL in the i.v. group (p < 0.05). Mean myocardial tissue concentration was not significantly different after BFO than i.v. perfusion (1.1 +/- 0.5 microg/g and 1.8 +/- 0.1 microg/g, respectively). In the endovascular BFO group, balloon-blocked pulmonary artery perfusion was successfully performed in all animals, and after 1 month, lung tissue showed no cytostatic-induced histologic changes., Conclusions: Compared with ILP, BFO cytostatic lung perfusion produced an insignificantly higher lung-tissue concentration, corresponding to a sixfold to ninefold higher level than after i.v. perfusion. Plasma drug levels during BFO perfusion were lower than during i.v. perfusion. Endovascular BFO may be a promising technique for repeated cytostatic lung perfusion.

Background: Cytostatic isolated lung perfusion has been advocated for treating pulmonary metastasis of soft tissue sarcoma. Different techniques of isolated lung perfusion have been developed., Methods: Isolated lung perfusion with and without doxorubicin was performed on white pigs during 15 minutes either by a single-pass system (n = 7) or by a recirculating-blood perfusion system (n = 7). Three animals with endovenous drug application served as controls. Leakage was assessed using isotopic tracers. Perfusion-induced lung tissue injury was determined by postperfusion chest radiographs, by angiotensin-converting enzyme-to-protein ratio in the plasma and in the bronchioalveolar lavage fluid, and by wet-to-dry weight ratio and histologic examination of lung biopsy specimens at 20 and 50 minutes. Doxorubicin concentration in lung tissue and plasma was compared between the three study groups., Results: All isolated lung perfusion studies were successfully performed without significant systemic leakage (< 0.6%). Wet-to-dry weight ratio was significantly lower after single-pass as compared with recirculating-blood perfusion and endovenous drug application at both time points (5.0 +/- 1.1 and 5.3 +/- 0.8 for single-pass versus 6.6 +/- 1.1 and 6.9 +/- 0.5 for recirculating-blood versus 6.6 +/- 0.2 and 5.9 +/- 0.7 for the control group, respectively; p < 0.05). Angiotensin-converting enzyme-to-protein plasma ratio in the single-pass group was significantly lower only at 20 minutes (6.3 +/- 2.4 versus 9.3 +/- 1.0 versus 9.7 +/- 1.9, respectively; p < 0.05) but not at 50 minutes. Angiotensin-converting enzyme-to-protein ratio in bronchoalveolar lavage fluid, histology of lung biopsy specimens, and chest radiographs did not differ significantly between the three groups. Doxorubicin lung tissue concentration was not significantly different after single-pass (17.5 micrograms/g) and recirculating-blood perfusion (21.9 micrograms/g), but was significantly higher than after endovenous drug application (3.0 micrograms/g; p < 0.01)., Conclusions: Both isolated lung perfusion techniques resulted in a sixfold to sevenfold higher doxorubicin lung tissue concentration than after endovenous application. Isolated lung perfusion-induced lung injury was similar for both techniques, but recirculating-blood perfusion appeared to result in more acute lung injury and was technically more demanding than single-pass perfusion.

The aim of this study was to set up a method for quantification of plasma mitomycin C (MMC) concentrations during intravesical chemotherapy delivered in the presence of local bladder hyperthermia (HT). In comparison with existing methods, this assay, characterized by relative simplicity and efficiency, resulted in the facilitation of performance with nondedicated instrumentation or nonspecialized staff. Purification from plasma matrix was carried out by solid-phase extraction under vaccuum. The purified drug was then collected directly into the vials of the HPLC autosampler. Chromatographic analysis was performed on a reversed-phase C18 column with water:acetonitrile (85:15 by vol) as the mobile phase and the UV detector set at 365 nm. The use of porfiromycin as internal standard provided a method with good within-day precision (CV 6.0% at 5 micrograms/L, n = 6), linearity (0.5-50 micrograms/L), and specificity. The lower limit of detection (< or = 0.5 microgram/L) proved to be suitable for plasma pharmacokinetics monitoring in two tested patients treated with MMC + HT for superficial bladder cancer.

We describe here an improved method of encapsulating doxorubicin in liposomes using phosphatidylcholine, cholesterol and synthetic tetramyristoyl cardiolipin. With this new composition of lipids the entrapment of doxorubicin was found to be > 90%. Cytotoxicity studies using vincristine-resistant HL-60/VCR leukaemia cells showed that liposome-encapsulated doxorubicin reverses multidrug resistance 5-fold compared with conventional doxorubicin and at levels equivalent to that obtained using liposomes with natural cardiolipin. In normal mice, liposome-encapsulated doxorubicin was much less toxic than the conventional drug. A dose of 25 mg kg-1 i.v. of conventional doxorubicin produced 100% mortality in mice by day 14, whereas liposomal doxorubicin exhibited only 10% mortality by day 60. Liposomal doxorubicin demonstrated enhanced anti-tumour activity against murine ascitic L1210 leukaemia compared with conventional doxorubicin. At a dose of 15 mg kg-1, liposomal doxorubicin increased the median life span with 12 of 18 long-term (60 days) survivors compared with only 3 of 18 with conventional drug. Mice injected i.v. with liposomal doxorubicin had plasma levels 44-fold higher than conventional doxorubicin, producing significantly higher (P < 0.02) area under the plasma concentration curve. An altered tissue distribution was also observed with liposomal doxorubicin; cardiac tissue demonstrating at least 2-fold lower levels with liposomal doxorubicin probably accounting for its lower toxicity. This altered pharmacokinetics of liposome-encapsulated doxorubicin, providing enhanced therapeutic advantage and the ability to modulate multidrug resistance, could be useful in a clinical setting.

The effect of the paclitaxel vehicle Cremophor on the pharmacokinetics of doxorubicin and doxorubicinol was studied in two groups of mice given intravenously either 2.5 ml kg-1 Cremophor or saline followed 5 min later by 10 mg kg-1 doxorubicin. In each group three mice were sacrificed at ten time points and doxorubicin and doxorubicinol were measured in plasma by high-performance liquid chromatography (HPLC). With Cremophor present, doxorubicin AUC increased from 1420+/-440 to 2770+/-660 ng h ml(-1) (P<0.05) and doxorubicinol AUC increased from 130+/-76 to 320+/-88 ng h ml(-1) (p<0.05). Neither the terminal elimination half-lives nor the doxorubicinol-doxorubicin AUC ratio changed in the presence of Cremophor, suggesting a lack of a direct effect on drug metabolism. The possibility exists the Cremophor may change the pharmacokinetics of both paclitaxel and other drugs given concurrently.

Annamycin (Ann) is a new lipophilic anthracycline antibiotic with a marked ability to circumvent typical multidrug resistance both in vitro and in vivo. Because of its high affinity for lipid membranes and very low solubility in water, Ann has been prepared in a submicron liposome formulation (L-Ann) that is currently being investigated in a Phase I clinical study. We studied the preclinical toxicity of L-Ann in mice and beagle dogs and compared it with that of free Ann in suspension and the parent compound doxorubicin (Dox). In mice, free Ann was about twice as toxic as Dox (LD50 after a single i.v. bolus administration, 8.8 versus 19.9 mg/kg; P < 0.01). The liposomal carrier reduced Ann toxicity by 2-fold (LD50, 15.74 mg/kg for L-Ann versus 8.8 mg/kg for free Ann; P < 0.01). Granulocytopenia was the main toxicity of Ann, either free or liposome incorporated, and was much more profound than with an equitoxic dose of Dox as assessed by blood counts and pathological studies. In chronic mouse studies, L-Ann was remarkably less cardiotoxic than Dox. Cumulative toxicity with the weekly administration of a given fraction of the subacute LD10 was markedly higher with Dox than with L-Ann as assessed by body weight and mortality studies. L-Ann also had less vesicant toxicity than Dox after intradermal administration in mice. Beagle dogs tolerated the mouse-equivalent LD10 dose of L-Ann (1.4 mg/kg) with no side effects, changes in the hematological and biochemical blood parameters, or pathological changes. Our results indicate that: (a) L-Ann is more selectively myelotoxic than Dox and is noncardiotoxic; (b) the liposome carrier plays a major role in the favorable toxicity profile of L-Ann; and (c) the standard one-tenth of the LD10 should be a safe starting dose for Phase I clinical trials with L-Ann in humans.