Sulfisoxazole

Sulfisoxazole

Quantitative determination of sulfisoxazole and its three N-acetylated metabolites using HPLC-MS/MS, and the saturable pharmacokinetics of sulfisoxazole in mice.[Pubmed:27454084]

J Pharm Biomed Anal. 2016 Sep 10;129:332-338.

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.

Simultaneous determination of N(1)-acetyl sulfisoxazole and its metabolites, and relative bioavailability compare to sulfisoxazole in rats.[Pubmed:27423008]

J Pharm Biomed Anal. 2016 Sep 10;129:117-120.

N(1)-acetyl Sulfisoxazole (N1AS), a dihydropteroate synthase inhibitor is known to be biotransformed primarily to Sulfisoxazole, partly to N(4)-acetyl Sulfisoxazole (N4AS), and likely also to diacetyl Sulfisoxazole (DAS) and other compounds. Although its clinical use has been limited due to urolithiasis, some countries still use the drug in combination with trimethoprim in cattle. A liquid chromatographic method using ultraviolet detection was developed for the simultaneous determination of four substances for the first time. Four analytes and sulfamethoxazole (IS) were separated on a reversed-phase column with gradient elution of a mobile phase. Because DAS and N1AS in plasma were changed very quickly into N4AS and Sulfisoxazole, respectively, and esterase inhibitors (sodium fluoride and eserine) could not prevent the transformation, Sulfisoxazole and N4AS were monitored in rat plasma following a single oral administration of N1AS and Sulfisoxazole in five rats. The relative bioavailability of N1AS to Sulfisoxazole was about two, indicating that a half-dose of N1AS would be equivalent to a dose of Sulfisoxazole to achieve the same systemic exposure to Sulfisoxazole.

Amplified electrochemical sensor employing CuO/SWCNTs and 1-butyl-3-methylimidazolium hexafluorophosphate for selective analysis of sulfisoxazole in the presence of folic acid.[Pubmed:28189110]

J Colloid Interface Sci. 2017 Jun 1;495:61-67.

In the present work, CuO nanoparticle decorated on single wall carbon nanotubes (CuO/SWCNTs) nanocomposite was successfully synthesized by chemical precipitation method and used for modification of carbon paste electrode (CPE) in the presence of 1-butyl-3-methylimidazolium hexafluorophosphate (1-B-3-MIHFP) liquid as binder. The novel voltammetric sensor was used as first electrochemical sensor for determination of Sulfisoxazole (SFX). CuO/SWCNTs nanocomposite characterized by scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) methods. Voltammetric methods such as cyclic voltammetry, square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS) and chronoamperometry were performed to assess the electrochemical performance of CuO/SWCNTs/1-B-3-MIHFP/CPE towards SFX in aqueous solution. The voltammetric obtained data confirm the significant enhancement of oxidation current and reduction overvoltage for electro-oxidation of SFX at a surface of CuO/SWCNTs/1-B-3-MIHFP/CPE. The square wave voltammetric response shows the linear increment of oxidation signals with an increase in the concentration of SFX in the range of 0.08-650muM with limit of detection 0.04muM. Using CuO/SWCNTs/1-B-3-MIHFP/CPE the SFX and folic acid peaks are separated ca. 0.72 and 0.895V, respectively; hence SFX can be detected in the presence of folic acid. Finally, the CuO/SWCNTs/1-B-3-MIHFP/CPE was used as high sensitive tools for analysis of SFX and folic acid in real samples.

Electro-catalytic degradation of sulfisoxazole by using graphene anode.[Pubmed:27155409]

J Environ Sci (China). 2016 May;43:54-60.

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.

Identification of a new class of ETA selective endothelin antagonists by pharmacophore directed screening.[Pubmed:8198578]

Biochem Biophys Res Commun. 1994 May 30;201(1):228-34.

Novel endothelin antagonists were identified through a "pharmacophore directed screening" strategy. The sulfanilamide antibacterial agent Sulfisoxazole was found to be a good endothelin receptor antagonist (IC50's of 0.60 microM and 22 microM for the ETA and ETB receptors, respectively). The structurally similar sulfamethoxazole was found to be a weaker antagonist (IC50 for ETA 16 microM and for ETB 230 microM). These compounds represent a new class of low molecular weight and ETA-selective non-peptide endothelin antagonists.