High performance liquid chromatographic determination of some co-administered anticancer drugs in pharmaceutical preparations and in spiked human plasma

The anti-tumor and renoprotection study of E-[c(RGDfK)2]/folic acid co-modified nanostructured lipid carrier loaded with doxorubicin hydrochloride/salvianolic acid A

Background

Poor in vivo targeting of tumors by chemotherapeutic drugs reduces their anti-cancer efficacy in the clinic. The discovery of over-expressed components on the tumor cell surface and their specific ligands provide a basis for targeting tumor cells. However, the differences in the expression levels of these receptors on the tumor cell surface limit the clinical application of anti-tumor preparations modified by a single ligand. Meanwhile, toxicity of chemotherapeutic drugs leads to poor tolerance to anti-tumor therapy. The discovery of natural active products antagonizing these toxic side effects offers an avenue for relieving cancer patients’ pain during the treatment process. Since the advent of nanotechnology, interventions, such as loading appropriate drug combinations into nano-sized carriers and multiple tumor-targeting functional modifications on the carrier surface to enhance the anti-tumor effect and reduce toxic and side effects, have been widely used for treating tumors.

Results

Nanocarriers containing doxorubicin hydrochloride (DOX) and salvianolic acid A (Sal A) are spherical with a diameter of about 18 nm; the encapsulation efficiency of both DOX and salvianolic acid A is greater than 80%. E-[c(RGDfK)2]/folic acid (FA) co-modification enabled nanostructured lipid carriers (NLC) to efficiently target a variety of tumor cells, including 4T1, MDA-MB-231, MCF-7, and A549 cells in vitro. Compared with other preparations (Sal A solution, NLC-Sal A, DOX solution, DOX injection, Sal A/DOX solution, NLC-DOX, NLC-Sal A/DOX, and E-[c(RGDfK)2]/FA-NLC-Sal A/DOX) in this experiment, the prepared E-[c(RGDfK)2]/FA-NLC-Sal A/DOX had the best anti-tumor effect. Compared with the normal saline group, it had the highest tumor volume inhibition rate (90.72%), the highest tumor weight inhibition rate (83.94%), led to the highest proportion of apoptosis among the tumor cells (61.30%) and the lowest fluorescence intensity of proliferation among the tumor cells (0.0083 ± 0.0011). Moreover, E-[c(RGDfK)2]/FA-NLC-Sal A/DOX had a low level of nephrotoxicity, with a low creatinine (Cre) concentration of 52.58 μmoL/L in the blood of mice, and no abnormalities were seen on pathological examination of the isolated kidneys at the end of the study. Sal A can antagonize the nephrotoxic effect of DOX. Free Sal A reduced the Cre concentration of the free DOX group by 61.64%. In NLC groups, Sal A reduced the Cre concentration of the DOX group by 42.47%. The E-[c(RGDfK)2]/FA modification reduced the side effects of the drug on the kidney, and the Cre concentration was reduced by 46.35% compared with the NLC-Sal A/DOX group. These interventions can potentially improve the tolerance of cancer patients to chemotherapy.

Conclusion

The E-[c(RGDfK)2]/FA co-modified DOX/Sal A multifunctional nano-drug delivery system has a good therapeutic effect on tumors and low nephrotoxicity and is a promising anti-cancer strategy.

Graphical Abstract

Tracking the Stepwise Formation of a Water-Soluble Fluorescent Tb12 Cluster for Efficient Doxorubicin Detection

Doxorubicin (DOX) is an anthraquinone drug used for the efficient treatment of a variety of tumors in human beings. Unfortunately, its poor biodegradability causes incomplete metabolism in the body. Therefore, it is of great significance to synthesize a sensitive and selective material for DOX detection. In this paper, we report a water-soluble Tb₁₂ cluster and track its step-by-step formation (L → Tb₁L₁ → Tb₂L₁ → Tb₂L₂ → Tb₃L₂ → Tb₄L₂ → Tb₁₂L₆). Tb₁₂ can be used to determine the presence of DOX, which quenches the luminescence of the Tb₁₂ aqueous solution, and the detection limit can reach 13 nM (K_SV = 8.7 × 10⁵ M^-1). Tb₁₂ has advantages of high sensitivity and high selectivity for the detection of DOX in a simulated environment of human urine and serum.

Electrochemical Sensor Based on Poly(Azure B)-DNA Composite for Doxorubicin Determination

A new voltammetric DNA sensor has been developed for doxorubicin determination on the platform of a glassy carbon electrode (GCE) covered with electropolymerized Azure B film and physically adsorbed native DNA. The redox properties of polymeric Azure B were monitored at various pH and scan rates. DNA application decreased the peak currents related to polymeric and monomeric forms of the dye, whereas incubation in doxorubicin solution partially restored the peaks in accordance with the drug and DNA concentration. The relative shift of the cathodic peak current caused by doxorubicin depended on the nominal DNA concentration and its application mode. In optimal conditions, the DNA sensor makes it possible to determine between 0.1 μM to 0.1 nM doxorubicin (limit of detection 7×10-11 M). The DNA sensor was tested on commercial doxorubicin formulations and on artificial samples the mimicked electrolyte content of human serum.

Selective Electrochemical Determination of Etoposide Using a Molecularly Imprinted Overoxidized Polypyrrole Coated Glassy Carbon Electrode

A simple and efficient new electrochemical sensor based on molecularly imprinted polymer has been developed for selective detection of an anticancer agent Etoposide (ETP). The sensor was prepared by electropolymerization via cyclic voltammetry (CV) of pyrrole onto a glassy carbon electrode (GCE) in the presence of ETP molecules. The extraction of ETP molecules embedded in the polymeric matrix was carried out by overoxidation in sodium hydroxide medium using CV. Various important parameters affecting the performance of the imprinted film (MIP) coated sensor were studied and optimized using differential pulse voltammetry (DPV). Under optimal conditions, the sensor response exhibited a linear dependence on ETP concentration (R2= 0.999) over the range 5.0×10−7M – 1.0×10−5M with a LOD (3σ/m) of 2.8×10−9M. The precision (% RSD, n=6) of the proposed sensor for intra- and interdays was found to be 0.84 and 2.46%, respectively. The selectivity of MIP/GCE sensor toward ETP was investigated in the presence of different interfering molecules including excipients and ETP metabolites. The developed sensor showed great recognition ability toward ETP and was successfully applied for its determination in injectable dosage forms and biological human fluids.

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.

Validation and clinical evaluation of a UHPLC method with fluorescence detector for plasma quantification of doxorubicin and doxorubicinol in haematological patients

A rapid and simple UHPLC-fluorescence detection method for the quantification of doxorubicin and its main metabolite, doxorubicinol, in human plasma has been developed. The method was also validated for its application in therapeutic drug monitoring, a clinical approach used in the optimization of oncologic treatments. Following a single protein precipitation step, chromatographic separation was achieved using a C18 column (50mm×2.10mm, particle size 1.7μm) at 50°C with a mobile phase consisting of water (containing 0.4% triethylamine and 0.4% orthophosphoric acid)/acetonitrile (77:23, v/v). Flow rate was 0.50mL/min and fluorescence detection with an excitation wavelength of 470nm and an emission wavelength of 548nm was used. The method met the specifications of linearity, selectivity, sensitivity, accuracy, precision and stability of the FDA and EMA guidelines for the validation of bioanalytical methods. Linearity for the drug (8-3000ng/mL) and the metabolite (3-150ng/mL) was observed (R(2)>0.992) and the maximum intra-day and inter-day precision coefficients of variation were less than 14% for both. The lower limits of quantification were 8 and 3ng/mL for doxorubicin and doxorubicinol, respectively. The method was successfully applied to the quantify plasma concentrations of doxorubicin and doxorubicinol in 33 patients diagnosed with haematological malignancies in which broad ranges for drug (8.3-2766.0ng/mL) and metabolite (4.8-104.9ng/mL) levels were measured adequately.

Total synchronous fluorescence spectroscopic data modeled with first- and second-order algorithms for the determination of doxorubicin in human plasma

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%.

Occurrence of cyclophosphamide and epirubicin in wastewaters by direct injection analysis-liquid chromatography-high-resolution mass spectrometry

BACKGROUND, AIM, AND SCOPE

According to the high incidence of cancer worldwide, the amount of cytostatic drugs administered to patients has increased. These compounds are excreted to wastewaters, and therefore become potential water contaminants. At this stage, very little is known on the presence and elimination of cytostatic compounds in wastewater treatment plants (WWTP). The aim of this study was to develop a liquid chromatography-high-resolution mass spectrometry (LC-Orbitrap-MS) method for the determination of cyclophosphamide and epirubicin in wastewaters. These compounds represent two outmost used cytostatic agents.

MATERIALS AND METHODS

Extraction and analytical conditions were optimized for cyclophosphamide and epirubicin in wastewater. Both solid-phase extraction using Oasis 200 mg hydrophilic-lipophilic balanced (HLB) cartridges and direct injection analysis were evaluated. Mass spectral characterization and fragmentation conditions were optimized at 50,000 resolving power (full width at half maximum, m/z 200) to obtain maximum sensitivity and identification performance. Quality parameters (recoveries, limits of detection, and repetitivity) of the methods developed were determined, and best performance was obtained with direct water analysis of the centrifuged wastewater. Finally, this method was applied to determine the presence of cyclophosphamide and epirubicin in wastewaters from a hospital effluent, an urban effluent, and influents and effluents from three WWTP.

RESULTS AND DISCUSSION

Cyclophosphamide and epirubicin were recovered after 50 mL preconcentration on solid-phase extraction 200 mg Oasis HLB cartridges (87% and 37%, respectively), and no breakthrough was observed by extracting 500 mL of water. Limits of detection were of 0.35 and 2.77 ng/L for cyclophosphamide and epirubicin, respectively. On the other hand, direct injection of water spiked at 1 μg/L provided recoveries of 107% for cyclophosphamide and 44% for epirubicin and limits of detection from 3.1 to 85 ng L(-1), respectively. The analysis of wastewaters using direct injection analysis revealed the presence of cyclophosphamide and epirubicin in WWTP influents and hospital and urban effluents at levels ranging from 5.73 to 24.8 μg L(-1).

CONCLUSIONS

The results obtained in this study demonstrate the capability of LC-Orbitrap-MS for accurate trace analysis of these very polar contaminants. This method permitted to identify cyclophosphamide and epirubicin in wastewaters and influents of WWTP, but no traces were detected in WWTP effluents. The methodology herein developed is sensitive and robust and applicable for screening of a large number of samples since no preconcentration is needed.

A comparison between ozonolysis and sonolysis/ozonolysis treatments for the degradation of the cytostatic drugs methotrexate and doxorubicin: Kinetic and efficiency approaches

Cytostatics are a major class of chemotherapy drugs with great potential to cause genotoxic and/or mutagenic effects in all organisms. Currently, hospital wastewater treatment systems (HWTS) are not able to remove these compounds and they are discharged to the environment. Thus, the objective of this study was to investigate the oxidative degradation of the cytostatic drugs doxorubicin (DOXO) [(8s,10s)-10-(4-amino-5-hydroxy-6-methyl-tetrahydro-2h-pyran-2-yloxy)-6,8,11-trihydroxy-8-(2-hydroxyacetyl)-1-methoxy-7,8,9,10-tetrahydrotetracene-5,12-dione] and methotrexate (METHO) {N-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-L-glutamic acid} by ozonolysis alone and using a combined sonolysis/ozonolysis process on bench-scale at different pH values. Besides determining the degradation efficiency, a kinetic approach was applied to determine the reaction order and rate constants for different oxidative processes carried out at pH 7.0, which is the normal pH of hospital wastewater. The results showed that the removal efficiency of these compounds is pH-dependent. A combination of sonolysis and ozonolysis processes is more efficient than the ozonolysis process alone for the degradation of doxorubicin at all pH values, while methotrexate can easily be degraded by ozonolysis alone or sonolysis/ozonolysis methodologies at any pH.

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.

Challenge of high polarity and low concentrations in analysis of cytostatics and metabolites in wastewater by hydrophilic interaction chromatography/tandem mass spectrometry

A method for solid phase extraction and HPLC-MS/MS of the cytostatics 5-fluorouracil, cytarabine, and gemcitabine and human metabolites uracil 1-beta-d-arabinofuranoside and 2',2'-difluorodeoxyuridine in wastewater was established. Wastewater samples from a Swiss hospital were analyzed for 5-fluorouracil, gemcitabine and 2',2'-difluorodeoxyuridine. The limits of quantification were 5.0, 0.9, and 9.0ng/L and the maximum concentrations detected were 27, 38, and 840ng/L, respectively. Along with the method development, retention mechanisms on the hydrophilic interaction chromatography (HILIC) stationary phase were studied. Both partitioning and adsorption play a role in the retention on the tested sulfoalkylbetaine modified silica HILIC column material. The contribution of these two processes is changing over the 1.6-40% range water in the mobile phase. Although the specific break point is difficult to determine, adsorption becomes more significant as the fraction of water in the mobile phase decreases below approximately 16%.

Supercritical Fluid Chromatography and High-Performance Liquid Chromatography/Tandem Mass Spectrometric Methods for the Determination of Cytarabine in Mouse Plasma

The separation of cytarabine (ara-C) from the endogenous compounds in mouse plasma by packed-column supercritical fluid chromatography (pSFC) was achieved on bare silica stationary phase with an isocratic mobile phase composed of CO2/methanol solvent with addition of ammonium acetate. SFC is commonly assumed to be only applicable to nonpolar and relatively low-polarity compounds. In this work, a broader range of compound polarities amenable to pSFC with appropriate mobile-phase modifiers and additives under normal-phase retention mechanism was demonstrated. The pSFC was integrated with an atmospheric pressure chemical ionization source and a tandem mass spectrometer (MS/MS) to enhance the sensitivity, selectivity, and speed of the assay. The influence of mobile-phase components on chromatographic performance and ionization efficiency of the test compounds was investigated for improving the sensitivity and separation for the analyte and the internal standard. The pSFC-MS/MS approach requiring approximately 2.5 min/sample for the determination of ara-C at nanograms per milliliter in mouse plasma was partially validated with respect to stability, linearity, and reproducibility. The mouse plasma levels of ara-C obtained by the pSFC-MS/MS method were found to be consistent with those determined by various reversed-phase, high-performance liquid chromatography methods using a porous graphite carbon column, a mixed-mode column, or a C18 column in conjunction with an ion-pairing agent coupled to a tandem mass spectrometer.

Selective determination of quinones by high-performance liquid chromatography with on-line post column ultraviolet irradiation and peroxyoxalate chemiluminescence detection

A new HPLC method was developed for the simultaneous determination of quinones with peroxyoxalate chemiluminescence (PO-CL) detection following on-line UV irradiation. Quinones [i.e., 1,2-naphthoquinone, 1,4-naphthoquinone, 9,10-anthraquinone, 9,10-phenanthrenequinone] were UV irradiated (254 nm, 15 W) to generate hydrogen peroxide and a fluorescent product that were determined via PO-CL detection. Generation of hydrogen peroxide from quinones with on-line UV irradiation was confirmed using flow injection analysis (FIA) system whereby incorporating an enzyme column reactor immobilized with catalase. Moreover, the structure of the produced fluorophore was confirmed using LC-MS, IR, and (1)H NMR. Afterwards, the conditions for UV irradiation and PO-CL detection were optimized. The separation of four quinones by HPLC was accomplished isocratically on an ODS column within 25 min. The detection limits (signal-to-noise ratio=3) were 6.0 pmol/injection for 1,2-naphthoquinone, 4.4 pmol/injection for 1,4-naphthoquinone, 0.2 pmol/injection for 9,10-anthraquinone, and 0.45 pmol/injection for 9,10-phenanthrenequinone.