Development of an HPLC method for simultaneous analysis of five antineoplastic agents

Multifunctional chitosan-bimetallic nanocarrier deliver 5-fluorouracil for enhanced treatment of pancreatic and triple-negative breast cancer

This work aimed to prepare multifunctional aptamer-conjugated, photothermally responsive 5-fluorouracil (5fu)-loaded chitosan-bimetallic (Au/Pd) nanoparticles (APT-CS-5fu-Au/Pd NPs) for improved cytotoxicity in two cancer cell lines (PANC-1 and MDA-MD 231). The CS-5fu-Au/Pd NPs were polydispersed with a size of 34.43 ± 1.59 nm. FTIR analysis indicated the presence of CS, 5fu in CS-5fu-Au/Pd NPs. The 2 theta degrees in CS-5fu-Au/Pd NPs accounted for CS and Au/Pd. Additionally, AGE revealed the conjugation of APT in CS-5fu-Au/Pd NPs. The APT-CS-5fu-Au/Pd NPs (180 μg/mL) with NIR treatment increased the temperature to >50 °C. The optimized 5fu input was 0.075 % in CS-5fu-Au/Pd NPs, exhibiting a hydrodynamic size of 112.96 ± 17.23 nm, DEE of 64.2 ± 3.77 %, and DLE of 11.1 ± 0.65 %. A higher level of 5fu release (69.8 ± 2.78 %) was observed under pH 5.4 at 74 h. In conclusion, NIR-APT-CS-5fu-Au/Pd NPs did not cause toxicity to RBC and Egg CAM, but increased cytotoxicity in MDA-MB 231 and PANC-1 cells by triggering oxidative stress-mediated cell death.

Residual contamination in antineoplastic drug packaging

INTRODUCTION

The handling of antineoplastic drugs should follow strict supervision and safety rules to minimize the occupational exposure risks to professionals involved. The external surface contamination of drug vials is recognized as a health risk. So, our goal was to determine if there is residual contamination on the vials and containers surface of the antineoplastic drugs doxorubicin (DOX) and cyclophosphamide (CP).

METHODS

A cross-sectional study was conducted. Samples were collected using a uniform sampling procedure on the inner surfaces of the packages/boxes and the outer surfaces of the vials. The analyzes were executed by high-performance liquid chromatography/mass spectrometry (UHPLC-MS/MS).

RESULTS

A total of 209 samples were analyzed, 66 of CP and 143 of DOX. CP levels were detected in nine samples (13.63%), three were below the lower limit of quantification (LLQ) and the other six had contamination levels ranging from 1.24 to 28.04 ng/filter. DOX levels were detected in 36 samples (25.17%), two were below the LLQ and the others had levels between 1.32 and 664.84 ng/filter. The majority of samples with residual contamination were in vials (80.0%), however, boxes also showed contamination.

CONCLUSIONS

The results revealed the presence of residual contamination in the vials and packages of CP and DOX drugs. Although the residues found in each sample are small, special care should be taken in the handling and disposal of the antineoplastic drugs. The use of personal protective equipment is fundamental while handling the vials and packaging of cytotoxic drugs.

The first facile optical density-dependent approach for the analysis of doxorubicin, an oncogenic agent accompanied with the co-prescribed drug; paclitaxel

Doxorubicin (DRB) is an anthracycline oncogenic drug extracted from cultures of Streptomyces peucetius var. caesius. It is frequently recommended as an anti-neoplastic agent for the treatment of diverse malignancies. It exerts its antineoplastic effect either via inhibiting the enzyme topoisomerase II and/or via intercalation to DNA or reactive oxygen species generation. In the present article, the direct, simple, one-pot, somewhat eco-safe, and non-extractive spectrophotometric system was executed to track doxorubicin, a chemotherapeutic remedy, in the presence of paclitaxel, a naturally occurring Taxan antineoplastic radical, through the greenness rated method. DRB's optical density was studied in various mediums and solvents to develop the current approach. An acidic ethanolic solution was found to increase the optical density of the sample significantly. At 480 nm., the most remarkable optical density was obtained. Various experimental factors, including intrinsic media, solvent, pH, and stability time, were investigated and controlled. The current approach achieved linearity within the 0.6-40.0 µg mL-1 range, accompanied by a limit of both detection and quantification (LOD and LOQ) of 0.18 and 0.55 µg mL-1, correspondingly. The approach was validated under the ICH guidelines (Quality Guidelines). The system's greenness and enhancement degree were estimated.

Occupational Exposure during Intraperitoneal Pressurized Aerosol Chemotherapy Using Doxorubicin in a Pig Model

Background

This study evaluated occupational exposure levels of doxorubicin in healthcare workers performing rotational intraperitoneal pressurized aerosol chemotherapy (PIPAC) procedures.

Methods

All samples were collected during PIPAC procedures applying doxorubicin to an experimental animal model (pigs). All procedures were applied to seven pigs, each for approximately 44 min. Surface samples (n = 51) were obtained from substances contaminating the PIPAC devices, surrounding objects, and protective equipment. Airborne samples were also collected around the operating table (n = 39). All samples were analyzed using ultra-high performance liquid chromatography-mass spectrometry.

Results

Among the surface samples, doxorubicin was detected in only five samples (9.8%) that were directly exposed to antineoplastic drug aerosols in the abdominal cavity originating from PIPAC devices. The telescopes showed concentrations of 0.48-5.44 ng/cm² and the trocar showed 0.98 ng/cm² in the region where the spraying nozzles were inserted. The syringe line connector showed a maximum concentration of 181.07 ng/cm², following a leakage. Contamination was not detected on the surgeons' gloves or shoes. Objects surrounding the operating table, including tables, operating lights, entrance doors, and trocar holders, were found to be uncontaminated. All air samples collected at locations where healthcare workers performed procedures were found to be uncontaminated.

Conclusions

Most air and surface samples were uncontaminated or showed very low doxorubicin concentrations during PIPAC procedures. However, there remains a potential for leakage, in which case dermal exposure may occur. Safety protocols related to leakage accidents, selection of appropriate protective equipment, and the use of disposable devices are necessary to prevent occupational exposure.

Validated HPLC-UV Method for Simultaneous Estimation of Paclitaxel and Doxorubicin Employing Ion Pair Chromatography: Application in Formulation Development and Pharmacokinetic Studies

Though paclitaxel (PTX) and doxorubicin (DOX) are amongst the most widely used and investigated drug pair for combination chemotherapy but surprisingly, not a single validated HPLC-UV method is available to analyze PTX and DOX simultaneously. So, herein a HPLC-UV method is developed and validated for the same, filling an indispensable gap in the literature. As these two moieties have characteristically different polarities, resolving them under the common chromatographic conditions is a challenging task. Herein, the principle of ion pair chromatography is utilized to resolve these two moieties on a C18 column employing an isocratic mobile phase comprised of acetonitrile and octane sulfonic acid buffer (67 : 37) and detected simultaneously at 231 nm using a UV detector only. The retention time is 4.4 and 7.2 min for PTX and DOX, respectively, with a total analysis time of less than 10 minutes, suitable for the formulation development and research, while LOQ is less than 0.066 μg/ml for both the drugs, suitable for the therapeutic drug monitoring at preclinical and clinical research setup. To substantiate the applicability of the developed method, a nanoformulation coloaded with PTX and DOX was designed and analyzed using the developed protocol. The method is also applied successfully to study the plasma kinetic profile of both the moieties simultaneously in Balb/c mice. Further, the method is validated as per the ICH guidelines fulfilling the unmet need of a validated analytical tool to simultaneously estimate PTX and DOX. Moreover, the results suggest that the principal of common ion chromatography demonstrated here can also be applied further for the simultaneous chromatographic separation of other polar and nonpolar moieties too. Consequently, the reported method surely will advance the toolset required for the precision-based combination chemotherapy.

Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles

New materials chemistries are urgently needed to overcome the limitations of existing biomedical materials in terms of preparation, functionality and versatility, and also in regards to their compatibility with biological...

Quantitative analysis of doxorubicin hydrochloride and arterolane maleate by mid IR spectroscopy using transmission and reflectance modes

Background

Environment-friendly fast and accurate mid-infrared spectroscopic methods have been developed for the quantitative analysis of doxorubicin hydrochloride (DOX) and arterolane maleate (ALM) in bulk and marketed formulations. Both transmittance and reflectance modes have been used for the analysis and a comparison has been drawn for better accuracy. The analytical methods were validated in accordance with International Council for Harmonisation (ICH) guidelines

Results

The proposed methods have been successfully developed and validated for the quantification of doxorubicin and arterolane maleate in solid bulk and dosage form. High recovery values in both the modes, while analysing DOX and ALM, indicated good accuracy of the methods. The methods showed excellent repeatability and intermediate precision [% RSD (Relative Standard Deviation < 2.0%]. The assay values of the drugs in solid dosage forms were also found close to the labelled claim.

Conclusion

The proposed Fourier transform infrared (FT-IR) spectroscopic methods were found to be specific, reproducible, valid and could be used as general methods for the quantification of most of the solid drug preparations such as tablets, capsules and powders.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13065-021-00752-3.

Optical Biosensors for Therapeutic Drug Monitoring

Therapeutic drug monitoring (TDM) is a fundamental tool when administering drugs that have a limited dosage or high toxicity, which could endanger the lives of patients. To carry out this monitoring, one can use different biological fluids, including blood, plasma, serum, and urine, among others. The help of specialized methodologies for TDM will allow for the pharmacodynamic and pharmacokinetic analysis of drugs and help adjust the dose before or during their administration. Techniques that are more versatile and label free for the rapid quantification of drugs employ biosensors, devices that consist of one element for biological recognition coupled to a signal transducer. Among biosensors are those of the optical biosensor type, which have been used for the quantification of different molecules of clinical interest, such as antibiotics, anticonvulsants, anti-cancer drugs, and heart failure. This review presents an overview of TDM at the global level considering various aspects and clinical applications. In addition, we review the contributions of optical biosensors to TDM.

Measuring extent of surface contamination produced by the handling of antineoplastic drugs in low- to middle-income country oncology health care settings

Antineoplastic drugs are known to cause detrimental effects to health care workers who are exposed through work tasks. Environmental monitoring studies are an excellent approach to measure the extent of surface contamination produced by the handling of antineoplastic drugs in the workplace and to assess the potential for occupational exposures in oncology health care settings. The main aim of the study was to establish the extent of surface contamination produced by the handling of antineoplastic drugs in a limited-resource oncology health care facility in Colombia by conducting an environmental monitoring study using affordable analytical instrumentation. Contamination with antineoplastic drugs was widespread in the health care facility under evaluation, which could result in health care worker exposure to antineoplastic drugs. A comprehensive review of current safety guidelines and protocols including assessment of adherence in the health care facility should be done.

Antineoplastic drugs and their analysis: a state of the art review

We provide an overview of the analytical methods available for the quantification of antineoplastic drugs in pharmaceutical formulations, biological and environmental samples.

A New Method to Quantify Ifosfamide Blood Levels Using Dried Blood Spots and UPLC-MS/MS in Paediatric Patients with Embryonic Solid Tumours

Ifosfamide blood concentrations are necessary to monitor its therapeutic response, avoiding any adverse effect. We developed and validated an analytical method by UPLC-MS/MS to quantify ifosfamide in dried blood spots (DBS). Blood samples were collected on Whatman 903® filter paper cards. Five 3 mm disks were punched out from each dried blood spot. Acetonitrile and ethyl acetate were used for drug extraction. Chromatographic separation was carried out in an Acquity UPLC equipment with a BEH-C18 column, 2.1 x 100 mm, 1.7 μm (Waters®). The mobile phase consisted in 5 mM ammonium formate and methanol:acetonitrile (40:48:12 v/v/v) at 0.2 mL/min. LC-MS/MS detection was done by ESI+ and multiple reaction mode monitoring, ionic transitions were m/z¹⁺ 260.99 > 91.63 for ifosfamide and 261.00 > 139.90 for cyclophosphamide (internal standard). This method was linear within a 100–10000 ng/mL range and it was accurate, precise and selective. Ifosfamide samples in DBS were stable for up to 52 days at -80°C. The procedure was tested in 14 patients, ages 1 month to 17 years (9 males and 5 females), with embryonic tumours treated with ifosfamide, alone or combined, at a public tertiary referral hospital. Ifosfamide blood levels ranged from 11.1 to 39.7 μmol/L at 12 hours after the last infusion, while 24-hour levels ranged from 0.7–19.7 μmol/L. The median at 12 hours was 19.5 μmol/L (Q₂₅ 14.4–Q₇₅ 29.0) and 3.8 μmol/L (Q₂₅ 1.5–Q₇₅ 9.9) at 24 hours, p<0.001. This method is feasible to determine ifosfamide plasma levels in paediatric patients.

Electroanalytical method for the determination of 5-fluorouracil using a reduced graphene oxide/chitosan modified sensor

A glassy carbon electrode (GCE) modified with a chemically reduced graphene oxide and chitosan (CRGO/CS) composite film was constructed and used to determine 5-fluorouracil using cyclic, staircase and square wave voltammetric techniques.

Engineering theranostic nanovehicles capable of targeting cerebrovascular amyloid deposits

Cerebral amyloid angiopathy (CAA) is characterized by the deposition of amyloid beta (Aβ) proteins within the walls of the cerebral vasculature with subsequent aggressive vascular inflammation leading to recurrent hemorrhagic strokes. The objective of the study was to develop theranostic nanovehicles (TNVs) capable of a) targeting cerebrovascular amyloid; b) providing magnetic resonance imaging (MRI) contrast for the early detection of CAA; and c) treating cerebrovascular inflammation resulting from CAA. The TNVs comprised of a polymeric nanocore made from Magnevist (MRI contrast agent) conjugated chitosan. The nanocore was also loaded with cyclophosphamide (CYC), an immunosuppressant shown to reduce the cerebrovascular inflammation in CAA. Putrescine modified F(ab')2 fragment of anti-amyloid antibody, IgG4.1 (pF(ab')24.1) was conjugated to the surface of the nanocore to target cerebrovascular amyloid. The average size of the control chitosan nanoparticles (conjugated with albumin and are devoid of Magnevist, CYC, and pF(ab')24.1) was 164±1.2 nm and that of the TNVs was 239±4.1 nm. The zeta potential values of the CCNs and TNVs were 21.6±1.7 mV and 11.9±0.5 mV, respectively. The leakage of Magnevist from the TNVs was a modest 0.2% over 4 days, and the CYC release from the TNVs followed Higuchi's model that describes sustained drug release from polymeric matrices. The studies conducted in polarized human microvascular endothelial cell monolayers (hCMEC/D3) in vitro as well as in mice in vivo have demonstrated the ability of TNVs to target cerebrovascular amyloid. In addition, the TNVs provided contrast for imaging cerebrovascular amyloid using MRI and single photon emission computed tomography. Moreover, the TNVs were shown to reduce pro-inflammatory cytokine production by the Aβ challenged blood brain barrier (BBB) endothelium more effectively than the cyclophosphamide alone.

Effects of outside air temperature on the preparation of antineoplastic drug solutions in biological safety cabinets

PURPOSE

In Japan, biological safety cabinets are commonly used by medical staff to prepare antineoplastic agents. At the Division of Chemotherapy for Outpatients, Nagoya University Hospital, a class II B2 biological safety cabinet is used. The temperature inside this biological safety cabinet decreases in winter. In this study, we investigated the effect of low outside air temperature on the biological safety cabinet temperature, time required to admix antineoplastic agents, and accuracy of epirubicin weight measurement.

METHODS

Studies were conducted from 1 January to 31 March 2008 (winter). The outside air temperature near the biological safety cabinet intake nozzle was compared with the biological safety cabinet temperature. The correlation between the outside air temperature and the biological safety cabinet temperature, time for cyclophosphamide and gemcitabine solubilization, and accuracy of epirubicin weight measurement were investigated at low and high biological safety cabinet temperatures.

RESULT

The biological safety cabinet temperature correlated with the outside air temperature of 5-20℃ (p < 0.0001). Compared to cyclophosphamide and gemcitabine solubilization in the biological safety cabinet at 25℃, solubilization at 10℃ was significantly delayed (p < 0.01 and p < 0.0001, respectively). Measurement of epirubicin weight by using a syringe lacked accuracy because of epirubicin's high viscosity at low temperatures (p < 0.01).

CONCLUSION

These results suggest that the biological safety cabinet temperature decreases when cool winter air is drawn into the biological safety cabinet, affecting the solubilization of antineoplastic agents. We suggest that a decrease in biological safety cabinet temperature may increase the time required to admix antineoplastic agents, thereby increasing the time for which outpatients must wait for chemotherapy.

A new, validated wipe-sampling procedure coupled to LC-MS analysis for the simultaneous determination of 5-fluorouracil, doxorubicin and cyclophosphamide in surface contamination

A wipe-sampling procedure followed by a simple liquid chromatography-mass spectrometry method was developed and validated for the simultaneous quantification of three cytotoxic drugs [5-fluorouracil (5FU), doxorubicin and cyclophosphamide (CP)] for the determination of surface contamination. After a solid-phase extraction procedure with wiping filter paper, the separation was performed within 30 min using a gradient mobile phase. The method was validated according to the recommendations of the US Food and Drug Administration. Wiping was performed using Whatman(®) filter paper on different surfaces such as stainless steel, polypropylene and glass. The method was linear, between 10 and 500 ng per wiping sample (i.e., 0.1-5 ng/cm(2)) for 5FU and doxorubicin, and between 1-100 ng per wiping sample (i.e., 0.01-1 ng/cm(2)) for CP. The lower limits of detection and quantification were 5 and 10 ng per wiping sample for 5FU and doxorubicin, and 0.5 and 1 ng per wiping sample for CP. This new sensitive methodology for surface contamination studies was successfully applied on commercial vials and different places in a cancer research hospital. This approach is particularly suitable to assess the risk of occupational exposure to cytotoxic drugs and to optimize the cleaning process, especially for the most toxic molecule studied, CP.

Development and application of a validated gradient elution HPLC method for simultaneous determination of 5-fluorouracil and paclitaxel in dissolution samples of 5-fluorouracil/paclitaxel-co-eluting stents

The combined use of 5-fluorouracil and paclitaxel is common in clinical trials. However, there are few methods for simultaneous determination of 5-fluorouracil and paclitaxel; most reported approaches can only quantitate either 5-fluorouracil or paclitaxel. This paper proposes a new gradient elution HPLC method for simultaneous determination of 5-fluorouracil and paclitaxel using a photodiode array detector, C₁₈ column (250 mm × 4.6 mm, 5 μm) with methanol and 0.5% H₃PO₄ aqueous solution as the mobile phase components. The injection volume was 50 μl and the column temperature was maintained at 30 °C. The method was validated according to USP Category I requirements. The validation characteristics included system suitability, linearity, analytical range, LOD, LOQ, accuracy, precision, specificity, stability, ruggedness and robustness. The calibration curves exhibited linear concentration ranges of 0.2-40 μg/ml for 5-fluorouracil and 1.5-150 μg/ml for paclitaxel with correlation coefficients larger than 0.99990. The lower limits of quantitation were 2 ng/ml for 5-fluorouracil and 0.75 μg/ml for paclitaxel, respectively. The intra and inter-day precision and accuracy were found to be well within acceptable limits (i.e., 5%). The results demonstrate that this method is reliable, reproducible and suitable for simultaneous quantitation of the two drugs in the release media of 5-fluorouracil/paclitaxel-co-eluting stents.

Analysis of anticancer drugs: a review

In the last decades, the number of patients receiving chemotherapy has considerably increased. Given the toxicity of cytotoxic agents to humans (not only for patients but also for healthcare professionals), the development of reliable analytical methods to analyse these compounds became necessary. From the discovery of new substances to patient administration, all pharmaceutical fields are concerned with the analysis of cytotoxic drugs. In this review, the use of methods to analyse cytotoxic agents in various matrices, such as pharmaceutical formulations and biological and environmental samples, is discussed. Thus, an overview of reported analytical methods for the determination of the most commonly used anticancer drugs is given.

Liquid-liquid extraction combined with high performance liquid chromatography-diode array-ultra-violet for simultaneous determination of antineoplastic drugs in plasma

A liquid-liquid extraction (LLE) combined with high-performance liquid chromatography-diode array detection method for simultaneous analysis of four chemically and structurally different antineoplastic drugs (cyclophosphamide, doxorubicin, 5-fluorouracil and ifosfamide) was developed. The assay was performed by isocratic elution, with a C18 column (5 µm, 250 x 4.6 mm) and mobile phase constituted by water pH 4.0- acetonitrile-methanol (68:19:13, v/v/v), which allowed satisfactory separation of the compounds of interest. LLE, with ethyl acetate, was used for sample clean-up with recoveries ranging from 60 to 98%. The linear ranges were from 0.5 to 100 µg mL-1, for doxorubicin and 1 to 100 µg mL-1, for the other compounds. The relative standard deviations ranged from 5.5 to 17.7%. This method is a fast and simple alternative that can be used, simultaneously, for the determination of the four drugs in plasma, with a range enabling quantification of the drugs in pharmacokinetics, bioequivalence and therapeutic drug-monitoring studies.

Sampling and mass spectrometric analytical methods for five antineoplastic drugs in the healthcare environment

CONTEXT

Healthcare worker exposure to antineoplastic drugs continues to be reported despite safe handling guidelines published by several groups. Sensitive sampling and analytical methods are needed so that occupational safety and health professionals may accurately assess environmental and biological exposure to these drugs in the workplace.

OBJECTIVE

To develop liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analytical methods for measuring five antineoplastic drugs in samples from the work environment, and to apply these methods in validating sampling methodology. A single method for quantifying several widely used agents would decrease the number of samples required for method development, lower cost, and time of analysis.

METHODS

for measuring these drugs in workers' urine would also be useful in monitoring personal exposure levels.

RESULTS

LC-MS/MS methods were developed for individual analysis of five antineoplastic drugs in wipe and air sample media projected for use in field sampling: cyclophosphamide, ifosfamide, paclitaxel, doxorubicin, and 5-fluorouracil. Cyclophosphamide, ifosfamide, and paclitaxel were also measured simultaneously in some stages of the work. Extraction methods for air and wipe samples were developed and tested using the aforementioned analytical methods. Good recoveries from the candidate air and wipe sample media for most of the compounds, and variable recoveries for test wipe samples depending on the surface under study, were observed. Alternate LC-MS/MS methods were also developed to detect cyclophosphamide and paclitaxel in urine samples.

CONCLUSIONS

The sampling and analytical methods were suitable for determining worker exposure to antineoplastics via surface and breathing zone contamination in projected surveys of healthcare settings.

Simultaneous detection of three antineoplastic drugs on gloves by liquid chromatography with diode array detector

The aim of this study was to develop a method for simultaneous detection of antineoplastic drugs on gloves since, in occupational exposure, the main contamination route is through dermal contact, which may occur via prolonged contact with contaminated surfaces or materials. The assay was performed by liquid chromatography using the following conditions for the detection of 5-fluorouracil (5-FU), methotrexate (MTX) and paclitaxel (TAX): diode array detection and UV quantification at 195 nm for TAX, at 265 nm for 5-FU and at 302 nm for MTX; ODS column (250 x 4 mm, 5 μm) with a similar guard column; mobile phase consisted of water (pH 4)-methanol-acetonitrile (35:15:50, v/v/v) with a flow rate of 1 mL min-1. The method presented a linear range from 0.25 to 20 μg mL-1 with r² higher than 0.99. Repeatability was <15% and satisfactory extraction efficiency was obtained when liquid-liquid extraction with ethyl acetate was used for 5-FU and TAX. Satisfactory solid phase extraction was also achieved with C18 cartridges and elution with methanol for MTX. The diode array detector allowed drug quantification at a concentration > 0.25 μg mL-1 in samples, although detection was possible in samples that presented values of around 0.1 μg mL-1. The results obtained suggest that the method developed can be applied for the simultaneous determination of the drugs studied and can be considered useful in exposure assessment for health care workers.

Sequential treatment of drug-resistant tumors with targeted minicells containing siRNA or a cytotoxic drug

The dose-limiting toxicity of chemotherapeutics, heterogeneity and drug resistance of cancer cells, and difficulties of targeted delivery to tumors all pose daunting challenges to effective cancer therapy. We report that small interfering RNA (siRNA) duplexes readily penetrate intact bacterially derived minicells previously shown to cause tumor stabilization and regression when packaged with chemotherapeutics. When targeted via antibodies to tumor-cell-surface receptors, minicells can specifically and sequentially deliver to tumor xenografts first siRNAs or short hairpin RNA (shRNA)-encoding plasmids to compromise drug resistance by knocking down a multidrug resistance protein. Subsequent administration of targeted minicells containing cytotoxic drugs eliminate formerly drug-resistant tumors. The two waves of treatment, involving minicells loaded with both types of payload, enable complete survival without toxicity in mice with tumor xenografts, while involving several thousandfold less drug, siRNA and antibody than needed for conventional systemic administration of cancer therapies.

Bacterially derived 400 nm particles for encapsulation and cancer cell targeting of chemotherapeutics

Systemic administration of chemotherapeutic agents results in indiscriminate drug distribution and severe toxicity. Here we report a technology potentially overcoming these shortcomings through encapsulation and cancer cell-specific targeting of chemotherapeutics in bacterially derived 400 nm minicells. We discovered that minicells can be packaged with therapeutically significant concentrations of chemotherapeutics of differing charge, hydrophobicity, and solubility. Targeting of minicells via bispecific antibodies to receptors on cancer cell membranes results in endocytosis, intracellular degradation, and drug release. This affects highly significant tumor growth inhibition and regression in mouse xenografts and case studies of lymphoma in dogs despite administration of minute amounts of drug and antibody; a factor critical for limiting systemic toxicity that should allow the use of complex regimens of combination chemotherapy.

Highly sensitive high-performance liquid chromatography/selective reaction monitoring mass spectrometry method for the determination of cyclophosphamide and ifosfamide in urine of health care workers exposed to antineoplastic agents

In recent years, the potential for exposure of health care workers to antineoplastic agents has led to the establishment of more restrictive government and professional standards and procedures for handling cytotoxic drugs. Therefore, the detection of low exposure levels is a new and important aim of biological monitoring. In the present paper we report an assay for the simultaneous determination of cyclophosphamide (CP) and ifosfamide (IF) in urine, using electrospray ionization liquid chromatography/tandem mass spectrometry with selective reaction monitoring (HPLC/SRM-MS). A rapid sample preparation procedure uses a solid-phase extraction stage with C18 columns. The urine assay is linear over the range 0.02 to 0.4 microg/L, with lower limits of quantification (LLOQs) of 0.02 and 0.04 microg/L for CP and IF. The accuracy and precision have been carried out through the validation study. The intra-day precision, expressed as relative standard deviation (RSD), is found to be always less than 14.7% for both analytes. The overall precision, assessed on three different days, is less than 15.0%. The recovery of ozaxaphosphorines ranges from 83.5% (CP) to 88.5% (IF) with a RSD always less than 14.6%. The uncertainty of the overall method was also evaluated, to identify possible sources of error. The combined uncertainty was less than 25% over all the days of the validation study. This method is selective and sensitive enough to determine trace levels of CP and IF in a range of urine concentrations relevant to performing low exposure assessment.

ABSORPTION OF INTRAVESICALLY APPLIED DRUGS: COMPARISON OF NORMAL AND ILEAL AUGMENTED RABBIT BLADDER

PURPOSE

Drug absorption within urinary diversions has been reported to cause prolonged and higher grade toxicity. Therefore, continuous urine drainage has been recommended during chemotherapy in patients with continent urinary diversion. We developed an animal model in which to examine the significance of drug absorption in normal rabbit bladders compared with ileal augmented bladders.

MATERIALS AND METHODS

Ten rabbits with ileal bladder augmentation and 5 control animals were used for absorption studies with methotrexate and ofloxacin. One, 4 and 12 months after surgery the rabbits received an intravesical instillation of either drug. During 2 hours blood samples were drawn. To avoid overfilling the bladder by urine it was emptied after 30, 60, 90 and 120 minutes, and refilled with fresh solution to yield a relatively constant drug amount. After 12 months the animals were sacrificed. Area of the native bladder wall and of the intestinal segment was measured to allow the correction of absorbed drug amounts per surface area. Moreover, the median villous heights of native and augmented ileum were compared histologically. Serum levels of methotrexate and ofloxacin were determined by high performance liquid chromatography.

RESULTS

The maximum serum concentration of the 2 drugs was typically seen after 60 to 120 minutes. During the 1-year period peak serum concentrations of ofloxacin remained consistently higher in ileal augmented than in control rabbits, although this did not achieve statistical significance at all instillation time points. For methotrexate a statistically significant difference was not shown for either time point. When absorption was corrected for total bladder surface area, the enhancement of ofloxacin absorption by ileal augmentation weakened and attained statistical significance only at the 1-month time point. Histological examinations after 12 months showed that augmented intestinal mucosa had a significantly smaller villous height than native ileum.

CONCLUSIONS

Our data demonstrate that bladder surface is the most important factor for increased absorption but time dependent histological changes of the integrated intestinal mucosa also influence absorption. There is a broad interindividual discrepancy. Therefore, general rules in patients with urinary diversion may not be justified.