Unraveling the electrochemical properties of lanthanum cobaltite decorated halloysite nanotube nanocomposite: An advanced electrocatalyst for determination of flutamide in environmental samples.

Prostate cancer is one of the primary causes of death around the world. As an important drug, flutamide has been used in the clinical diagnosis of prostate cancer. However, the over dosage and improper discharge of flutamide could affect the living organism. Thus, it necessary to develop the sensor for detection of flutamide with highly sensitivity. In this paper, we report the synthesis of lanthanum cobaltite decorated halloysite nanotube (LCO/HNT) nanocomposite prepared by a facile method and evaluated for selective reduction of flutamide. The as-prepared LCO/HNT nanocomposite shows the best catalytic performance towards detection of flutamide, when compared to other bare and modified electrodes. The good electrochemical performance of the LCO/HNT nanocomposite modified electrode is ascribed to abundant active sites, large specific surface area and their synergetic effects. Furthermore, the LCO/HNT modified electrode exhibits low detection limit (0.002 µM), wide working range (0.009-145 µM) and excellent selectivity with remarkable stability. Meaningfully, the developed electrochemical sensor was applied in real environmental samples with an acceptable recovery range.

Innovative Strategy Based on a Novel Carbon-Black-ß-Cyclodextrin Nanocomposite for the Simultaneous Determination of the Anticancer Drug Flutamide and the Environmental Pollutant 4-Nitrophenol.

In the present work, a noncovalent and eco-friendly approach was proposed to prepare a carbon-black/ß-cyclodextrin (CB/ß-CD) nanocomposite. CB/ß-CD-nanocomposite-modified screen-printed carbon electrodes were applied for the simultaneous determination of the anticancer drug flutamide (Flut) and the environmental pollutant 4-nitrophenol (4-NP). The electrochemical performance of the proposed sensor relied on the conductivity of CB, the different binding strengths of the guests (Flut and 4-NP) to the host (ß-CD), and the different reduction potentials of the nitroaromatic compounds. Fascinatingly, the proposed sensor exhibited an excellent electrochemical performance with high sensitivity, selectivity, and reproducibility. The obtained wide linear ranges were 0.05-158.3 and 0.125-225.8 µM for Flut and 4-NP. The low detection limits of 0.016 and 0.040 µM with the higher sensitivities of 5.476 and 9.168 µA µM-1 cm-2 were achieved for the determination of Flut and 4-NP, respectively. The practical feasibility of the proposed sensor was studied in tap-water and human-serum samples.

Optimization of Electrochemical Sensitivity in Anticancer Drug Quantification through ZnS@CNS Nanosheets: Synthesis via Accelerated Sonochemical Methodology.

Zinc sulfide/graphitic Carbon Nitride binary nanosheets were synthesized by using a novel sonochemical pathway with high electrocatalytic ability. The as- obtained samples were characterized by various analytical methods such as Transmission Electron Microscopy (TEM), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS) to evaluate the properties of ZnS@CNS synthesized by this new route. Subsequently, the electrical and electrochemical performance of the proposed electrodes were characterized by using EIS and CV to establish an electroactive ability of the nanocomposites. The complete properties like structural and physical of ZnS@CNS were analyzed. As-prepared binary nanocomposite was applied towards the detection of anticancer drug (flutamide) by various electrochemical methods such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry. The glassy carbon electrode modified with a ZnS@CNS composite demonstrates a remarkable electrocatalytic efficiency for detecting flutamide in a pH 7.0 (PBS). The composite modified electrode shows synergistic effect of ZnS and CNS catalyst. The electrochemical sensing performance of the linear range was improved significantly due to high electroactive sites and rapid electron transport pathways. Crucially, the electrochemical method was successfully demonstrated in biological fluids which reveals its potential real-time applicability in the analysis of drug.

Molecular dynamics simulation of drug delivery across the cell membrane by applying gold nanoparticle carrier: Flutamide as hydrophobic and glutathione as hydrophilic drugs as the case studies.

In this study, molecular dynamics simulation is applied to investigate drug transport in both pure state and conjugated with neutral gold nanoparticle (AuNP) as a drug carrier inside dipalmitoylphosphatidylcholine (DPPC) membrane. Flutamide (Flu) as a hydrophobic and Glutathione (GSH) as a hydrophilic anticancer drug are selected as the case studies. Dynamics of each drug including adhesion on and penetration into the cell membrane are investigated. Pure and conjugated form of drugs inside the water and near the membrane are studied. Simulation results show that the interaction between drug molecules and DPPC changes after drug conjugating with AuNP. GSH, as a hydrophilic drug, intends to remain above the membrane bilayer and after conjugating with AuNP diffuses inside DPPC. However, hydrophobic Flu molecule likes to diffuse inside DPPC, but after conjugating with AuNP, its diffusion inside the lipid bilayer decreases, and its retention time at the surface of DPPC increases. Presence of Flu-NP at the surface of DPPC could enhance its impact on blocking dihydrotestosterone binding at androgen receptors resulting in tumor cell growth arrest. In addition, the tendency of GSH-NP for diffusion to the DPPC is a positive factor for the successful transport of heavy metals such as AuNP without rapid clearance through either the hepatobiliary pathway or the renal system. In conclusion, such MD simulation results may solve problems in nanomedicine translation and turn into a bridge toward maximizing targeting and minimizing nanotoxicity of metal NPs.

Resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectra of copper(II)-Flutamide system with anionic surfactants and its analytical application.

A simple, sensitive, and rapid method based on ion association, for the determination of FLD has been developed. Flutamide (FLD) can react with Cu(II) to form 1:1 cationic chelate at pH 2.2-7.0 Mclivaine buffer medium, which can further react with anionic surfactants (AS) such as sodium dodecyl sulfate (SDS), sodium lauryl sulfonate (SLS) and sodium dodecylbenzene sulfonate (SDBS) to form 1:1 ion-association complexes. As a result, the resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced to the highest degree. The maximum RRS, SOS and FDS wavelengths of three ion-association complexes were located at 345/345 nm, 610/305 nm and 430/860 nm, respectively. The increments of scattering intensity (ΔI) were directly proportional to the concentration of FLD in certain ranges. The detection limits (3σ) of FLD for SDS, SLS and SDBS systems were 1.9 ng ml(-1), 2.1 ng ml(-1) and 2.2 ng ml(-1)(RRS method), 2.4 ng ml(-1), 2.7 ng ml(-1) and 2.6 ng ml(-1) (SOS method) and 2.3 ng ml(-1), 2.4 ng ml(-1) and 2.5 ng ml(-1) (FDS method), separately. The sensitivity of RRS method was higher than those of FDS and SOS methods. The optimum conditions of RRS method and the influence factors, the composition and the reaction mechanism have been discussed. Since the method is highly selective, it does not interference concomitant substances. These methods were applied successfully for the determination of FLD in pharmaceutical formulation and urine samples.

Ultrasonication and hydrothermal assisted synthesis of cloud-like zinc molybdate nanospheres for enhanced detection of flutamide.

Ultrasonication is one of the emerging probes for nanoparticles synthesis as well as promoting the material property by treasuring the precious time during a chemical reaction. In this present work, we successfully designed a cloud-like α-ZnMoO4 nanospheres (ZMNS) using ultrasound assistance (bath sonication with the power of 60 W and frequency of 37/80 kHz) hydrothermal method for catalyzing the effective electrochemical determination of anti-androgen drug candidate flutamide (FLT). The crystallinity and phase purity were investigated using powder X-ray diffractometric analysis. The FTIR and Raman spectra information were compared to detect the possible bonding in ZMNS. The texture and surface morphology were studied using Field emission scanning electron microscope and High-resolution Transmission electron microscope images. The presence of the elements (Zn, Mo and O) and the absence of any other impurities were monitored and confirmed using EDAX analysis. The fabrication of ZMNS modified GCE was performed carefully. Additionally, the ZMNS modified glassy carbon electrode (GCE) exhibits superior electrocatalytic activity by means of higher cathodic peak current towards the detection of FLT. The fashioned electrode attained two wide linear response ranges (0.1 to 73 µM; 111 to 1026 µM) with a lower detection limit of about 33 nM correspondingly. Furthermore, the fabricated sensor displayed excellent sensitivity of 1.095 µA µM-1 cm-2 and good selectivity for FLT sensing even in the existence of similar interfering compounds and biomolecules. Along with that, the designed sensor executed noticeable reproducibility, repeatability, and enduring stability.

Chitosan-gold collapse gel/poly (bromophenol blue) redox-active film. A perspective for selective electrochemical sensing of flutamide.

Chitosan-gold collapse gel (CS-Au CG) was prepared by reducing chloroauric acid (HAuCl4) with a polysaccharide, chitosan (CS), in the absence of chemical and physical agents. CS-Au CG was used for the first time as a suitable nano-biocomposite sensing film for efficient one-step electrochemical deposition of poly (bromophenol blue) (PBPB) redox mediator through amino-hydroxyl reaction to prepare a novel anti-androgen drug flutamide (FLU) sensor using glassy carbon electrode (GCE). The effect of electropolymerization cycle, scan rate, pH, and concentration of CS-Au CG/PBPB film on electrochemical behavior of FLU molecules was investigated. The excellent synergetic effect of CS-Au CG/PBPB film showed substantially enhanced electrocatalytic activity for FLU due to the halogen-nitro synthon molecular recognition processes. The selectivity of CS-Au CG/PBPB film sensor for FLU was discussed in detail. The fabricated electrochemical sensor exhibited good linearity in the ranges of 0.01-1245 µM. And also superior sensitivity (0.63 µAµM-1 cm-2) along with low limit of detection (4.8 nM) was obtained for FLU determination. The CS-Au CG/PBPB film showed an excellent selectivity, good reproducibility, and stability. In addition, the proposed sensor was successfully used to analysis of FLU drug in human urine and human blood serum samples with satisfactory results.

Broadband dielectric spectroscopy as an experimental alternative to calorimetric determination of the solubility of drugs into polymer matrix: Case of flutamide and various polymeric matrixes.

In this paper we determined the solubility limits of the amorphous flutamide within the two different polymeric matrixes - poly vinylpyrrolidone and poly vinylacetate. In order to achieve this goal, series of broadband dielectric spectroscopy measurements were performed. As a result we found that the maximal amount of the drug that can be successfully dissolved within the PVAc (maintaining the non-supersaturated conditions) is equal to 35 wt% of the amorphous solid dispersion system. Interestingly enough similar results, in terms of solubility limits, were achieved utilizing significantly higher amount of the pharmaceutical - 71 wt% - in the PVP matrix. Accordingly, we established the following relationship in the solubility limits of the amorphous flutamide dispersed within examined polymer matrixes: PVP > PVAc. It is worth highlighting that in order to preserve the thermodynamic stability - one of the two contributors to the physical stability - drug loading in the amorphous solid dispersion system should not exceed its solubility limits. Hence, choosing appropriate amount of the polymer addition will determine if obtained system remains physically stable. Subsequently, we presented the "stability maps" for all investigated FL-based ASD systems from which one might predict the stabilization effect exerted by certain amount of polymer.

Automated determination of flutamide by a validated flow-injection method: application to dissolution studies of pharmaceutical tablets.

The first flow-injection (FI) method for the determination of flutamide--a potent antiandrogen used for the treatment of prostate cancer--is reported. The method is based on the direct measurement of the absorbance of the analyte at 310 nm under flow conditions. Parameters affecting the determination such as detection wavelength, sample injection volume and flow rate were studied and optimized. The assay was validated (linearity, limits of detection and quantitation, accuracy, repeatability, reproducibility and selectivity) for the dissolution studies of flutamide-containing tablets during stability testing. The results were in good agreement with high performance liquid chromatography (HPLC) used as a reference method.

Two different spectrophotometric determinations of potential anticancer drug and its toxic metabolite.

Flutamide is a hormone therapy used for men with advanced prostate cancer. Flutamide is highly susceptible to hydrolysis with the production of 3-(trifluoromethyl)aniline, which is reported to be one of its toxic metabolites, impurities and related substances according to BP and USP. Flutamide was found to be stable when exposed to oxidation by 30% hydrogen peroxide and direct sunlight for up to 4h. Two accurate and sensitive spectrophotometric methods were used for determination of flutamide in bulk and in pharmaceutical formulations. Method (I) is the area under curve (AUC) spectrophotometric method that depends on measuring the AUC in the wavelength ranges of 275-305 nm and 350-380nm and using Cramer's rule. The linearity range was found to be 1-35 µg/mL and 0.5-16 µg/mL for the drug and the degradate, respectively. In method (II), combination of the isoabsorptive and dual wavelength spectrophotometric methods was used for resolving the binary mixture. The absorbance at 249.2 nm (λiso) was used for determination of total mixture concentration, while the difference in absorbance between 232 nm and 341.2 nm was used for measuring the drug concentration. By subtraction, the degradate concentration was obtained. Beer's law was obeyed in the range of 2-35 µg/mL and 0.5-20 µg/mL for the drug and its degradate, respectively. The two methods were validated according to USP guidelines and were applied for determination of the drug in its pharmaceutical dosage form. Moreover AUC method was used for the kinetic study of the hydrolytic degradation of flutamide. The kinetic degradation of flutamide was found to follow pseudo-first order kinetics and is pH and temperature dependent. Activation energy, kinetic rate constants and t1/2 at different temperatures and pH values were calculated.

Appropriate column configurations for the rapid analysis and semipreparative purification of the radiolabeled drug flutamide by high-performance liquid chromatography.

Flutamide, marketed as Eulexin, is used for treatment of metastic prostatic carcinoma. Purity of a radiolabeled batch for metabolism studies was first determined by reversed-phase HPLC on a 5 microm, 150x4.6 mm analytical column. The separation was then scaled up to give a semipreparative column (5 microm, 250x10 mm) purification procedure. Fraction analysis was done on a short rapid analysis (5 microm, 50x3.0 mm) column. Analysis of the final product was performed on the analytical column. All columns were YMC-Pack ODS-AQ. The analytical work involved large mass injections in order to have the required amounts of radioactivity needed for accurate impurity profile determinations, and the preparative work involved masses much larger than the calculated scale-up values. Ultraviolet and radiochromatograms of the drug on the various column configurations are compared. A 95.7% recovery of product was obtained, with radiochemical purity increased from 95.0 to 99.8%.

Novel reagents for the sensitive spectrophotometric determination of flutamide, an anticancer drug in pharmaceutical preparations.

Simple and sensitive spectrophotometric methods for the determination of flutamide (FLA) in either pure form or in its pharmaceutical preparations are described. The first method is based on the diazotisation of reduced FLA, followed by coupling with alcoholic iminodibenzyl (IDB) in acid medium to give a purple coloured product having a lambda(max) of 570 nm. In the second method, the diazotisation of reduced FLA followed by coupling with 4-amino-5-hydroxy-2,7-naphthalenedisulphonic acid monosodium salt (AHND) in a buffer medium of pH 12, gives a red coloured product having a lambda(max) of 520 nm. Common excipients used as additives in pharmaceutical preparations do not interfere in the proposed methods. Both the methods are highly reproducible and have been applied to a wide variety of pharmaceutical preparations and the results compare favourably with the reported method.

Polarographic determination of flutamide.

The polarographic reduction of flutamide was investigated by direct current polarography (DCP), alternating current polarography (ACP), normal pulse polarography (NPP) and differential pulse polarography (DPP). The supporting solution was phosphate buffer containing 5% of 95% ethanol. The reduction process at the dropping mercury electrode was diffusion controlled and irreversible. Extraction with 95% ethanol followed by polarographic reduction was selected as the basis of a method for the determination of flutamide as a pure compound and in tablets.

New spectrophotometric method for the determination of flutamide in pharmaceutical preparations.

A sensitive and simple spectrophotometric method for the determinations of reduction product of flutamide (FLA) is described. The method is based on the interaction of diazotized flutamide reduction product with N-(1-naphthyl) ethylenediamine dihydrochloride (NEDA) in neutral or resorcinol (RSL) in alkaline medium. Absorbance of the resulting chromophores is measured at 525 or 480 nm, respectively, and is stable for at least 7 days. The two coupling reagents are applied successfully for the determination of FLA in tablets. The common excipients used as additives in pharmaceutical preparations do not interfere with the determination. Results from the analysis of pure FLA and its commercial tablets by the proposed methods agree well with the reported method.

Successful detection of (anti-)androgenic and aromatase inhibitors in pre-spawning adult fathead minnows (Pimephales promelas) using easily measured endpoints of sexual development.

Screening assays have been successfully developed for the detection of (anti-)oestrogenic substances in several fish species, including the fathead minnow (Pimephales promelas). Previous work suggested that pre-spawning adult fathead minnows might be an appropriate life-stage for developing a screen to detect endocrine active substances (EASs). Pre-spawning adult fathead minnows, in which their phenotypic sex could be determined, were exposed in flow-through systems to three reference substances for 21 days, at 25 degrees C. Male and female fish, held in separate tanks, were exposed to dihydrotestosterone (DHT, androgen), flutamide (anti-androgen) and fadrozole (aromatase inhibitor). Nominal (mean measured) concentrations for DHT were 10 (6.0), 32 (6.1) and 100 (8.6) microg l(-1), for flutamide, 100 (95.3), 320 (320.4) and 1000 (938.6) microg l(-1) and for fadrozole, 25 (24.8), 50 (51.7) and 100 (95.5) microg l(-1). After 14 and 21 days exposure, fish were evaluated for growth, secondary sexual characteristics (SSCs, number and prominence of nuptial tubercles), gonadosomatic index (GSI) and plasma vitellogenin (VTG) concentrations. Development of nuptial tubercles was sensitive to both DHT and flutamide exposure. Exposure to DHT significantly increased the number of nuptial tubercles (male characteristic) in both males (more abundant) and females, after 14 days. Flutamide (938.6 microg l(-1), day 21) significantly reduced nuptial tubercle number in male fish. Fadrozole significantly inhibited ovarian growth (lower GSI) and significantly induced testis growth (51.7 and 95.5 microg l(-1)), after 21 days. Plasma VTG concentrations were significantly elevated in male fish (6.1 and 8.6 microg l(-1)), but inhibited in female fish (6.0 microg l(-1)), exposed to DHT. Flutamide had no effect on plasma VTG in male fish, but significantly induced VTG in female fish, after 21 days. Fadrozole significantly inhibited VTG in females and induced VTG synthesis in males, at day 21. These results show that SSCs, GSI and plasma VTG concentrations can be used in pre-spawning adult fathead minnows to screen for a range of classes of EASs. This work complements other published studies in supporting the current OECD effort towards validating a 21 days non-spawning fish screening assay for assessing (anti-)oestrogens, aromatase inhibitors and (anti-)androgens.

[Sex-difference on flutamide metabolism in rat liver microsomal cytochrome P450 1A2].

AIM: To assess the sex-difference on flutamide metabolism in rat liver microsomes useing rat cytochrome P450, 1A2, inhibitory monoclonal antibody. METHODS: Liver microsomes were prepared from male or female rats. Protein concentration and total cytochrome P450 content were determined. Incubation mixture included liver microsomes (1.0 nmol.L-1), reduced form of nicotinamide adenine dinucleotide phosphate (NADPH, 0.1 nmol.L-1), CYP1A2 (1:400) and flutamide (2 mg.L-1). The incubation time was 30 min. The concentration of flutamide and its major metabolite 2-hydroxyflutamide were analyzed by reverse high-performance liquid chromatography. The mobile phase was a mixture of methanol-acetonitrile-water-diethylether (40:20:35:1) with methyltestosterone as internal standard. The detection wavelength was 234 nm. The reaction mixture was extracted with acetic ether 4 mL. Sex-difference on flutamide metabolism was expressed as the difference between the concentration ratio of 2-hydroxyflutamide to flutamide in male and female rat liver microsomes. RESULTS: The recoveries of flutamide and 2-hydroxyflutamide for the proposed method were more than 75%. The formation of 2-hydroxyflutamide from flutamide was inhibited by CYP1A2 antibodies (1:400) in male and female rat liver microsome for 30 min of incubation time, but the inhibition of flutamide metabolism in female rat was stronger than that in male. The concentration ratios of 2-hydroxyflutamide to flutamide were (1.5 +/- 0.6) and (0.9 +/- 0.4) in male and female rat liver microsomes, respectively (P < 0.01). CONCLUSION: The results indicate that the activity of male rat CYP1A2 is higher than that of the female rat. There is difference in sex-related rate of flutamide metabolism in rat liver microsomes.

A novel luminol chemiluminescent method catalyzed by silver/gold alloy nanoparticles for determination of anticancer drug flutamide.

It was found that silver/gold alloy nanoparticles enhance the chemiluminescence (CL) of the luminol-H2O2 system in alkaline solution. The studies of UV-Vis spectra, CL spectra, effects of concentrations luminol, hydrogen peroxide and silver/gold alloy nanoparticles solutions were carried out to explore the CL enhancement mechanism. Flutamide was found to quench the CL signals of the luminol-H2O2 reaction catalyzed by silver/gold alloy nanoparticles, which made it applicable for the determination of flutamide. Under the optimum conditions, the CL intensity is proportional to the concentration of the flutamide in solution over the range 5.0 × 10(-7) to 1.0 × 10(-4)mol L(-1). Detection limit was obtained 1.2 × 10(-8)mol L(-1)and the relative standard deviation (RSD) γ5%. This work is introduced as a new method for the determination of flutamide in commercial tablets. Box-Behnken experimental design is applied to investigate and validate the CL measurement parameters.

Biopolymeric microparticles combined with lyophilized monophase dispersions for controlled flutamide release.

Despite its short half-life, no controlled release formula of flutamide (FLT) was prepared until now. Therefore, 15 chitosan microparticle formulations were prepared for oral prolonged delivery of FLT via ionotropic gelation and emulsification-ionic gelation techniques then characterized for various parameters. FLT was successfully encapsulated into microparticles with loading capacity up to 39.98% and entrapment efficiency up to 97.16% using emulsification technique. Differential scanning calorimetry indicated that FLT was retained in a crystalline form in the microparticles prepared using ionotropic gelation whereas its crystallinity was significantly reduced using emulsification technique. Relationship between formulation variables and release behavior of FLT was explored. Chitosan microparticles prepared by ionotropic gelation showed a slower FLT release with a T(25%) of 7.9h whereas microparticles prepared by emulsification-ionic gelation under the same conditions showed a quick release profile with a T(25%) of 0.3h. Using 3 different hydrophilic carriers, immediate release FLT dispersions were prepared via lyophilization of monophase solution technique then combined with prolonged release chitosan microparticles to develop 6 controlled release formulae of FLT. A wide range of FLT release profiles were generated providing a prolonged release of drug after a suitable initial burst release.

Concepts and limitations in the application of radiolabeled antiandrogens, estrogens, or androgens as isotopic scanning agents for the prostate.

The distribution of labeled antiandrogens, estrogens, and androgens has been studied in the rat and dog to elucidate the principles and limitations encountered when these agents are used in radioscanning the prostate. The bulk of the label is rapidly cleared in the biliary secretions and in the urine. The concentration of label in the prostate in comparison to other tissues such as the intestines limits the application of these agents in radioscanning of the prostate. The tissue distributions were confirmed by total body radioscans of rats and dogs receiving a labeled 3'-iodinated analog of the antiandrogen flutamide (Sch 13521 or 3'-trifluoromethyl-4'-nitroisobutyranilide).