RESUMEN
The mechanism of sulfisoxazole (SFF) selective removal by photocatalysis in the presence of titanium (IV) oxide (TiO2) and iron (III) chloride (FeCl3) was explained and the kinetics and degradation pathways of SFF and other antibiotics were compared. The effects of selected inorganic ions, oxygen conditions, pH, sorption processes and formation of coordination compounds on the photocatalytic process in the presence of TiO2 were also determined. The Fe3+ compounds added to the irradiated sulfonamide (SN) solution underwent surface sorption on TiO2 particles and act as acceptors of excited electrons. Most likely, the SFF degradation is also intensified by organic radicals or cation organic radicals. These radicals can be initially generated by reaction with electron holes, hydroxyl radicals and as a result of electron transfer mediated by iron ions and then participate in propagation processes. The high sensitivity of SFF to decomposition caused by organic radicals is associated with the steric effect and the high bond polarity of the amide substituent.
Asunto(s)
Antibacterianos/química , Sulfonamidas/química , Titanio/química , Catálisis , Concentración de Iones de Hidrógeno , Cinética , Compuestos Orgánicos , Fotólisis , Sulfisoxazol/química , Purificación del AguaRESUMEN
New functionalized acrylamide derivatives bearing sulfisoxazole moiety were designed to target bacterial dihydropteroate synthase (DHPS). The in vitro antimicrobial activities of these compounds were assessed. The E-configuration of compound 5b was proved by single crystal X-ray analysis. Compounds 5g and 5h displayed double the activity of ampicillin against B. subtilis. Also, 5h was two times more active than gentamycin against E. coli. Interestingly, compounds 5f-g, 7c, 8a, 8c exhibited two folds the potency of amphotericin B against S. racemosum while 5h displayed three folds the activity of amphotericin B against S. racemosum. Most of the synthesized compounds showed superior activities to the parent sulfisoxazole and were non-toxic to normal cells. DHPS is confirmed to be a putative target for our compounds via antagonizing their antibacterial activity by the folate precursor (p-aminobenzoic acid) and product (methionine) on E. coli ATCC 25922. Docking experiments against DHPS rationalized the observed antibacterial activity. Additionally, compound 5g was evaluated as a selective targeting vector for 99mTc that showed a remarkable uptake and targeting ability towards the infection site that was induced in mice.
Asunto(s)
Acrilamida/farmacología , Antibacterianos/farmacología , Dihidropteroato Sintasa/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Sulfisoxazol/farmacología , Acrilamida/química , Antibacterianos/síntesis química , Antibacterianos/química , Células Cultivadas , Dihidropteroato Sintasa/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/crecimiento & desarrollo , Humanos , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Estructura Molecular , Relación Estructura-Actividad , Sulfisoxazol/químicaRESUMEN
The widespread occurrence of sulfonamides (SAs) in natural waters, wastewater, soil and sediment has raised increasing concerns about their potential risks to human health and ecological systems. Sulfate radical (SO4-)-based advanced oxidation processes (SR-AOPs) have become promising technologies to remove such contaminants in the environment. The present study systematically investigated the degradation of four selected SAs with different five-membered heterocyclic rings, namely, sulfamethoxazole (SMX), sulfisoxazole (SIX), sulfathiazole (STZ), and sulfamethizole (SMT), by thermo-activated persulfate (PS) process, and the role of heterocyclic rings was assessed particularly. The results revealed that all the selected SAs could be degraded efficiently by thermo-activated PS process and their decay rates were appreciably increased with increasing temperature. For instance, degradation rates of STZ increased from 0.3â¯×â¯10-3 to 19.5â¯×â¯10-3â¯min-1 as the temperature was increased from 30 to 60⯰C. Under the same experimental conditions, the degradation rates of SAs followed the order of SIX > SMXâ¯≈â¯STZâ¯>â¯SMT, which was in accordance with decay rates of their R-NH2 moieties. Kinetic results indicated that five-membered heterocyclic rings could serve as reactive moieties toward SO4- attack, which were confirmed by frontier electron density (FED) calculations. Based on the transformation products identified by high-resolution mass spectrometry (HR-MS), five different oxidation pathways, including hydroxylation, aniline moiety oxidation, dimerization, sulfonamide bond cleavage, and heterocyclic ring oxidation/cleavage were proposed. Moreover, the degradation efficiency in real surface water (RSW) was found to be slightly slower than that in artificial surface water (ASW), suggesting that SR-AOPs could be an efficient approach for remediation of soil and water contaminated by these SAs.
Asunto(s)
Antibacterianos/química , Restauración y Remediación Ambiental/métodos , Contaminantes del Suelo/química , Sulfatos/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Oxidación-Reducción , Sulfametizol/química , Sulfametoxazol/química , Sulfatiazol/química , Sulfisoxazol/químicaRESUMEN
As robust polymeric catalysts, graphitic carbon nitride (g-C3N4) has been known to have great application potential in environmental remediation. However, the mechanisms in the photo-assisted catalytic processes during the reduction or oxidation of pollutants are still difficult to discern and therefore not well studied. In this work, visible-assisted catalytic reduction of hexavalent chromium (Cr(VI)) or oxidation of sulfisoxazole (SIZ) by g-C3N4 with the addition of formic acid (FA) or potassium peroxydisulfate (PS) were systematically investigated. Effects of operation parameters such as g-C3N4 dosage, FA concentration, Cr(VI) concentration, solution pH, PS concentration were studied. The results showed g-C3N4 can be effective and robust catalyst for both the reduction (Yin) and oxidation (Yang) reactions in the environmental remediation. Mechanisms were studied by using electron spin resonance (ESR) spectroscopy. The results revealed the CO 2- is the predominant radical for Cr(VI) reduction in the g-C3N4/FA/Vis system and the SO4- and OH are all the main radicals for the oxidation of SIZ in the g-C3N4/PS/Vis system. The photo-generated carriers by g-C3N4, act as radical initiator, were responsible for the production of the reactive radical species in aqueous solution. This work not only shed a new light on the application of semiconductor polymers for the removal of micropollutants and also will expand the applicability of the polymeric photocatalysts for environmental remediation.
Asunto(s)
Cromo/química , Restauración y Remediación Ambiental/métodos , Nitrilos/química , Sulfisoxazol/química , Catálisis , Contaminantes Ambientales/química , Contaminantes Ambientales/aislamiento & purificación , Grafito , Oxidación-Reducción , Polímeros , SemiconductoresRESUMEN
To determine the preferred water molecule binding sites of the polybasic sulfa drugs sulfamethoxazole (SMX) and sulfisoxazole (SIX), we have studied their monomers and monohydrated complexes through laser-desorption conformer-specific UV and IR spectroscopy. Both the SMX and SIX monomer adopt a single conformer in the molecular beam. On the basis of their conformer-specific IR spectra in the NH stretch region, these conformers were assigned to the SMX and SIX global minimum structures, both exhibiting a staggered sulfonamide group and an intramolecular C-HO[double bond, length as m-dash]S hydrogen bond. The SMX-H2O and SIX-H2O complexes each adopt a single isomer in the molecular beam. Their isomeric structures were determined based on their isomer-specific IR spectra in the NH/OH stretch region. Quantum Theory of Atoms in Molecules analysis of the calculated electron densities revealed that in the SMX-H2O complex the water molecule donates an O-HN hydrogen bond to the heterocycle nitrogen atom and accepts an N-HO hydrogen bond from the sulfonamide NH group. In the SIX-H2O complex, however, the water molecule does not bind to the heterocycle but instead donates an O-HO[double bond, length as m-dash]S hydrogen bond to the sulfonamide group and accepts an N-HO hydrogen bond from the sulfonamide NH group. Both water complexes are additionally stabilized by a Cph-HOH2 hydrogen bond. Interacting Quantum Atoms analysis suggests that all intermolecular hydrogen bonds are dominated by the short-range exchange-correlation contribution.
Asunto(s)
Antiinfecciosos/química , Sulfametoxazol/química , Sulfisoxazol/química , Agua/química , Sitios de Unión , Fenómenos Biofísicos , Humanos , Enlace de Hidrógeno , Luz , Modelos Moleculares , Estructura Molecular , Teoría Cuántica , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Relación Estructura-Actividad , Sulfanilamida/químicaRESUMEN
In this study, our aim was to develop solid drug-cyclodextrin inclusion complex system having nanofibrous morphology in order to have fast-dissolving property and enhanced water-solubility of poorly water-soluble drug. Here, we prepared a highly concentrated aqueous solution of inclusion complex between sulfisoxazole and sulfobutyl ether7-beta-cyclodextrin (SBE7-ß-CD, Captisol®), and then, without using any polymeric matrix, the electrospinning of sulfisoxazole/SBE7-ß-CD-IC nanofibers was performed in order to obtain free-standing and handy nanofibrous web. As a control sample, nanofibers from pure SBE7-ß-CD was also electrospun and free-standing nanofibrous web was obtained. The SEM imaging revealed that the bead-free and uniform nanofiber morphology with the average fiber diameter (AFD) of 650±290nm for sulfisoxazole/SBE7-ß-CD-IC NF and 890±415nm for pure SBE7-ß-CD NF was obtained. The inclusion complex formation between sulfisoxazole and SBE7-ß-CD in sulfisoxazole/SBE7-ß-CD-IC NF sample was confirmed by 1H NMR, TGA, DSC, XRD and FTIR analyses. Due to the combined advantage of cyclodextrin inclusion complexation and high surface area of electrospun nanofibers, fast-dissolving property with enhanced water-solubility was successfully achieved for sulfisoxazole/SBE7-ß-CD-IC NF. Our findings suggest that electrospun nanofibers/nanowebs from CD-IC of poorly water-soluble drugs may offer applicable approaches for high water-solubility and fast-dissolving tablet formulations for drug delivery systems.
Asunto(s)
Portadores de Fármacos/química , Nanofibras/química , Sulfisoxazol/química , beta-Ciclodextrinas/química , Polímeros , SolubilidadRESUMEN
Sulfisoxazole (SFX) is still used in combination with trimethoprim in cattle despite adverse drug reactions (e.g., urolithiasis). Recently, SFX is known to be a promising repositioned drug candidate for pulmonary hypertension and cancer. We developed a simultaneous determination method of SFX and its N-acetylated metabolites (N(1)-acetyl SFX, N1AS; N(4)-acetyl SFX, N4AS; diacetyl SFX, DAS) using HPLC-MS/MS for the first time, and examined the pharmacokinetics of SFX in mice. N1AS and DAS were converted rapidly to SFX and N4AS, respectively, in mouse plasma. The time courses of plasma SFX and N4AS concentrations were well-characterised following the oral administration of SFX to mice. The absorption, metabolism, and/or excretion of SFX given at >700mg/kg may be saturable, and in contrast to humans and rats, the extent of systemic exposure of mice to N4AS was much greater than that of SFX. Interestingly, the acetyl groups at both N1- and N4-positions were degraded during the ionisation required to generate precursor ions. In additional experiments the carboxyl group of N-acetyl-5-aminosalicylic acid (NA5AS) was lost instead of the acetyl group during the ionisation, and acetaminophen (AAP) appeared. As the acetyl and carboxyl groups of some substances can be degraded during ionisation in the mass spectrometer, caution is appropriate when it is sought to simultaneously quantify similar structures containing these moieties; chromatographic separation is essential.
Asunto(s)
Sulfisoxazol/química , Sulfisoxazol/farmacocinética , Acetaminofén/química , Acetaminofén/farmacocinética , Administración Oral , Ácido Aminosalicílico/química , Ácido Aminosalicílico/farmacocinética , Animales , Cromatografía Líquida de Alta Presión/métodos , Humanos , Ratones , Ratas , Espectrometría de Masas en Tándem/métodosRESUMEN
Graphite and graphene electrodes were prepared by using pure graphite as precursor. The electrode materials were characterized by a scanning electron microscope (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV) measurements. The electro-catalytic activity for degradation of sulfisoxazole (SIZ) was investigated by using prepared graphene or graphite anode. The results showed that the degradation of SIZ was much more rapid on the graphene than that on the graphite electrode. Moreover, the graphene electrode exhibited good stability and recyclability. The analysis on the intermediate products and the measurement of active species during the SIZ degradation demonstrated that indirect oxidation is the dominant mechanism, involving the electro-catalytic generation of OH and O2(-) as the main active oxygen species. This study implies that graphene is a promising potential electrode material for long-term application to electro-catalytic degradation of organic pollutants.
Asunto(s)
Electrodos , Contaminantes Ambientales/química , Grafito/química , Sulfisoxazol/química , Técnicas ElectroquímicasRESUMEN
Microbial resistance to the available drugs poses a serious threat in modern medicine. We report the design, synthesis and in vitro antimicrobial evaluation of new functionalized 2,3-dihydrothiazoles and 4-thiazolidinones tagged with sulfisoxazole moiety. Compound 8d was most active against Bacillis subtilis (MIC, 0.007 µg/mL). Moreover, compounds 7c-d and 8c displayed significant activities against B. subtilis and Streptococcus pneumoniae (MIC, 0.03-0.06 µg/mL and 0.06-0.12 µg/mL versus ampicillin 0.24 µg/mL and 0.12 µg/mL; respectively). Compounds 7a and 7c-d were highly potent against Escherichia coli (MIC, 0.49-0.98 µg/mL versus gentamycin 1.95 µg/mL). On the other hand, compounds 7e and 9c were fourfolds more active than amphotericin B against Syncephalastrum racemosum. Molecular docking studies showed that the synthesized compounds could act as inhibitors for the dihydropteroate synthase enzyme (DHPS). This study is a platform for the future design of more potent antimicrobial agents.
Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Relación Estructura-Actividad , Tiazoles/química , Antiinfecciosos/síntesis química , Sitios de Unión , Técnicas de Química Sintética , Dihidropteroato Sintasa/antagonistas & inhibidores , Dihidropteroato Sintasa/química , Dihidropteroato Sintasa/metabolismo , Diseño de Fármacos , Evaluación Preclínica de Medicamentos/métodos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Sulfisoxazol/química , Tiazoles/farmacologíaRESUMEN
Although sulfonamides (SAs) are among the most commonly used veterinary drugs and their presence in the environment is well documented, knowledge of their fate and behavior in the soil environment is still limited, especially for sulfisoxazole (SSX) which is characterized by the lowest (among other SAs) pK a value associated with acid-base equilibrium of sulfonamide group. Thus, this work was focused on determining the sorption potential of SSX onto natural soils differing in physicochemical properties. All the results were modeled using linear, Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin sorption isotherms. The established sorption coefficients (K(d)) for SSX were quite low (from 0.27 to 0.95 L kg(-1)), which indicated that this substance is highly mobile and has the potential to run off into surface waters and/or infiltrate ground water. The sorption data of SSX is well fitted to the Freundlich isotherm model (R(2) > 0.968). Moreover, we assessed the sorption mechanism of these compounds in the edaphic environment with respect to organic matter (OM) content, pH, and ionic strength. To clarify the current state of knowledge, these factors were examined much more thoroughly than in previous investigations concerning other SAs. The wide range of ionic strength examined showed positive correlation of this factor and sorption of SAs. The results also yielded new insight into dependency of sorption of SAs on organic matter content in soil.
Asunto(s)
Contaminantes del Suelo/química , Suelo/química , Sulfisoxazol/química , Drogas Veterinarias/química , Equilibrio Ácido-Base , Adsorción , Modelos QuímicosRESUMEN
Herein, hydroxypropyl-beta-cyclodextrin (HPßCD) inclusion complex (IC) of a hydrophobic drug, sulfisoxazole (SFS) was incorporated in hydroxypropyl cellulose (HPC) nanofibers (HPC/SFS/HPßCD-IC-NF) via electrospinning. SFS/HPßCD-IC was characterized by DSC to investigate the formation of inclusion complex and the stoichiometry of the complex was determined by Job's plot. Modeling studies were also performed on SFS/HPßCD-IC using ab initio technique. SEM images depicted the defect free uniform fibers and confirmed the incorporation of SFS/HPßCD-IC in nanofibers did not alter the fiber morphology. XRD analyses showed amorphous distribution of SFS/HPßCD-IC in the fiber mat. Release studies were performed in phosphate buffered saline (PBS). The results suggest higher amount of SFS released from HPC/SFS/HPßCD-IC-NF when compared to free SFS containing HPC nanofibers (HPC/SFS-NF). This was attributed to the increased solubility of SFS by inclusion complexation. Sandwich configurations were prepared by placing HPC/SFS/HPßCD-IC-NF between electrospun PCL nanofibrous mat (PCL-HPC/SFS/HPßCD-IC-NF). Consequently, PCL-HPC/SFS/HPßCD-IC-NF exhibited slower release of SFS as compared with HPC/SFS/HPßCD-IC-NF. This study may provide more efficient future strategies for developing delivery systems of hydrophobic drugs.
Asunto(s)
Antiinfecciosos/química , Celulosa/análogos & derivados , Portadores de Fármacos , Nanofibras/química , Sulfisoxazol/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Celulosa/química , Celulosa/ultraestructura , Liberación de Fármacos , Técnicas Electroquímicas , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Nanofibras/ultraestructura , Tamaño de la Partícula , SolubilidadRESUMEN
Development of new antimicrobial agents is a good solution to overcome drug-resistance problems. In this context, new functionalized thiophene, acrylamide, arylhydrazone, pyrazole and pyridone derivatives bearing sulfisoxazole moiety were designed, synthesized and evaluated for their in vitro antibacterial and antifungal activities. Among the synthesized compounds, thiophene 4d and 6-thioglucosylpyridone 17 displayed significant antibacterial activities against Escherichia coli (MIC, 0.007 µg/mL vs gentamycin 1.95 µg/mL) and Bacillis subtilis (MIC, 0.007 µg/mL vs ampicillin 0.24 µg/mL), respectively. Whereas, the pyrazole 6 showed the highest antifungal activity against Aspergillus fumigates (MIC, 0.03 µg/mL vs amphotericin B 0.12 µg/mL). In general, most of the synthesized compounds exhibited better antimicrobial activities than sulfisoxazole; this might be attributed to the synergistic effect of the sulfonamide and attached heterocyclic moieties as well as the increased lipophilic characters of the synthesized compounds. Molecular docking studies indicated that the synthesized compounds could occupy both p-amino benzoic acid (PABA) and pterin binding pockets of the dihydropteroate synthase (DHPS), suggesting that the target compounds could act by the inhibition of microbial DHPS enzyme. The results provide important information for the future design of more potent antimicrobial agents.
Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Simulación del Acoplamiento Molecular , Pirazoles/farmacología , Piridonas/farmacología , Sulfisoxazol/química , Tiofenos/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Aspergillus/efectos de los fármacos , Bacillus subtilis/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pirazoles/síntesis química , Pirazoles/química , Piridonas/síntesis química , Piridonas/química , Relación Estructura-Actividad , Tiofenos/síntesis química , Tiofenos/químicaRESUMEN
The Fluorescence spectroscopic and solvatochromic behavior of Sulfisoxazole, a sulfa drug with antimicrobial activities, in various pure solvents of different polarity and hydrogen bonding capability is reported. The fluorescence emission spectrum of sulfisoxazole was found to be solvent polarity dependent, where a notable red shift in emission maximum was observed with increasing solvent polarity as well as hydrogen bonding capability. The effects of the latter two solvent parameters were quantitatively investigated using the methods of Lippert-Mataga and solvatochromic comparison method (SCM) that is based on the Kamlet-Taft equation. Particularly, the Lippert-Mataga method was applied to estimate the dipole moment of the excited state (µ(e)) upon plotting Stokes shift versus solvent polarizability (Δf), where a value of 11.54 Debye was obtained. On the other hand, applying the multiple regression analysis to the SCM method revealed that solvent polarizability (π*) and hydrogen-bond donor capability (α) approximately equally stabilize sulfisoxazole in the excited state with minor destabilization contribution by the hydrogen-bond acceptor capability (ß). These findings revealed that the excited state of sulfisoxazole is stabilized by polar solvents, indicating that this drug molecules exhibit larger dipole moment in the excited state than in the ground state, which in turn implies that a potential intramolecular charge transfer (ICT) occurs after excitation.
Asunto(s)
Fluorescencia , Solventes/química , Sulfisoxazol/química , Antibacterianos , Antiinfecciosos/química , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , SulfonamidasRESUMEN
The synthesis, structural characterization, voltammetric experiments and antibacterial activity of [Ni(sulfisoxazole)(2)(H(2)O)(4)].2H(2)O and [Ni(sulfapyridine)(2)] were studied and compared with similar previously reported copper complexes. [Ni(sulfisoxazole)(2)(H(2)O)(4)].2H(2)O crystallized in a monoclinic system, space group C2/c where the nickel ion was in a slightly distorted octahedral environment, coordinated with two sulfisoxazole molecules through the heterocyclic nitrogen and four water molecules. [Ni(sulfapyridine)(2)] crystallized in a orthorhombic crystal system, space group Pnab. The nickel ion was in a distorted octahedral environment, coordinated by two aryl amine N from two sulfonamides acting as monodentate ligands and four N atoms (two sulfonamidic N and two heterocyclic N) from two different sulfonamide molecules acting as bidentate ligands. Differential pulse voltammograms were recorded showing irreversible peaks at 1040 and 1070 mV, respectively, attributed to Ni(II)/Ni(III) process. [Ni(sulfisoxazole)(2)(H(2)O)(4)].2H(2)O and [Ni(sulfapyridine)(2)] presented different antibacterial behavior against Staphylococcus aureus and Escherichia coli from the similar copper complexes and they were inactive against Mycobacterium tuberculosis.
Asunto(s)
Antibacterianos , Bacterias/efectos de los fármacos , Níquel/química , Compuestos Organometálicos , Sulfapiridina , Sulfisoxazol , Sulfonamidas , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Cristalografía por Rayos X , Escherichia coli/efectos de los fármacos , Mycobacterium tuberculosis/efectos de los fármacos , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/química , Compuestos Organometálicos/farmacología , Staphylococcus aureus/efectos de los fármacos , Sulfapiridina/síntesis química , Sulfapiridina/química , Sulfapiridina/farmacología , Sulfisoxazol/síntesis química , Sulfisoxazol/química , Sulfisoxazol/farmacología , Sulfonamidas/síntesis química , Sulfonamidas/química , Sulfonamidas/farmacologíaRESUMEN
BACKGROUND: Measuring plasma unbound bilirubin concentration by the peroxidase test is useful in the management of jaundiced newborns. However, the commercially available peroxidase technology is manual, and the unbound bilirubin may be seriously underestimated at the 42-fold sample dilution and single peroxidase concentration used. We investigated improving the test by adapting it to Zone Fluidics, which is a system for automating reactant handling that requires small sample volumes and dilution. METHODS: A computer-directed Zone Fluidics system was constructed using small diameter tubing to connect in series a water-surfactant reservoir, a bi-directional pump, a multiport selection valve to which peroxidase test reactants (45 mul of sample) are attached with one port open to air, and a spectrophotometer flow cell. Test reactants and air are sequentially aspirated through the valve into the tubing connecting the pump and valve to form a reactant "zone" surrounded by air. The zone is advanced to the spectrophotometer flow cell where total and unbound bilirubin are determined (37 degrees C) from the absorbance at 460 nm at a 2-fold sample dilution and 4 peroxidase concentrations. Imprecision was assessed in artificial controls and newborn plasma. Plasma results were compared with those obtained using the commercial method. RESULTS: The CV for unbound bilirubin in the various controls ranged from 11% to 38% (within day) and 12% to 27% (between days). Triplicate CV measurements for newborn plasma measurements ranged from 0.6% to 31% (mean 11%, n=47). Mean unbound bilirubin by Zone Fluidics was 5-fold higher than that by the commercial method. CONCLUSION: Zone Fluidics can be used to automate the peroxidase test and overcome many of the limitations of the commercially available peroxidase technology.
Asunto(s)
Bilirrubina/sangre , Monitoreo Fisiológico/métodos , Peroxidasa/metabolismo , Calibración , Humanos , Recién Nacido , Ictericia Neonatal/sangre , Reproducibilidad de los Resultados , Sulfisoxazol/químicaRESUMEN
BACKGROUND: A belief that brand oral liquid medications taste better than their generic counterparts may influence prescribing habits among pediatricians. METHODS: We undertook a prospective, randomized, double blinded, comparative evaluation of the taste of brand and generic erythromycin ethylsuccinate, cephalexin monohydrate, erythromycin ethylsuccinate/sulfisoxazole, penicillin V potassium and trimethoprim-sulfamethoxazole in 42 adult volunteers. Subjects tasted one class of brand and generic antibiotics and rated them according to smell, texture, taste and aftertaste. RESULTS: At least one generic preparation of cephalexin, erythromycin ethylsuccinate/sulfisoxazole and penicillin V potassium was rated equal in taste to the respective brand name products. However, brand erythromycin estolate and trimethoprim-sulfamethoxazole name brand suspensions rated significantly higher than the other products tested. CONCLUSIONS: Based on our results brand name oral antibiotic formulations do not necessarily taste better than their generic counterparts.
Asunto(s)
Antibacterianos/química , Medicamentos Genéricos , Olfato , Gusto , Administración Oral , Adulto , Anciano , Cefalexina/química , Método Doble Ciego , Composición de Medicamentos , Quimioterapia Combinada/química , Eritromicina/química , Etilsuccinato de Eritromicina/química , Femenino , Humanos , Masculino , Persona de Mediana Edad , Penicilina V/química , Sulfisoxazol/química , Combinación Trimetoprim y Sulfametoxazol/químicaRESUMEN
BACKGROUND: The taste of oral liquid medications influences compliance in children. Generic preparations are prescribed to reduce cost and may taste worse than brand name products. METHODS: This was a prospective, randomized, double blind, crossover trial of the differences in taste and compliance between brand and generic antibiotic suspensions in children 3 to 14 years of age. Verbal and visual assessment methods were used to assess taste, and compliance was measured by the amount of drug returned after use. RESULTS: Ten children in each of the cephalexin and erythromycin-sulfisoxazole groups did not report that the brand and generic formulations tasted differently. Fifteen children thought that brand trimethoprim-sulfamethoxazole tasted better than the generic preparation. CONCLUSIONS: Brand name oral liquid antibiotics do not necessarily taste better than their generic counterparts. Despite preference for the taste of brand trimethoprim-sulfamethoxazole, all of the children in this study were compliant with both brand and generic medications.
Asunto(s)
Antibacterianos/química , Cooperación del Paciente , Gusto , Adolescente , Antibacterianos/economía , Cefalexina/química , Niño , Preescolar , Método Doble Ciego , Composición de Medicamentos , Quimioterapia Combinada/química , Quimioterapia Combinada/economía , Medicamentos Genéricos/química , Medicamentos Genéricos/economía , Eritromicina/química , Femenino , Humanos , Masculino , Satisfacción del Paciente , Sulfisoxazol/química , Combinación Trimetoprim y Sulfametoxazol/químicaRESUMEN
The brine shrimp Artemia, an excellent live food source in aquaculture, has been studied as a carrier to deliver selected chemotherapeutic agents to fish for prophylactic treatment of infectious diseases. To monitor the efficiency of incorporation of trimethoprim and sulfamethoxazole in Artemia franciscana, a sensitive and specific analytical method was developed. It is based on homogenization of Artemia nauplii in methanol, extraction of lipids with hexane, solid-phase cleanup on C18 cartridges, and reversed-phase liquid chromatography with detection at 210 nm. The method is sensitive (detection limit, on the order of 3 micrograms/g with a sample quantity of 30 mg [dry weight]) and reproducible (coefficients of variation, 2.2 and 1.8% for trimethoprim and sulfamethoxazole at levels of 79.6 and 257 micrograms/g of body weight, respectively). Preliminary quantitative data indicated excellent uptake and persistence of both therapeutic agents in A. franciscana, with levels of 115 micrograms/g for trimethoprim and 277 micrograms/g for sulfamethoxazole.