Graziano Varani

Rapid methods for determination of fluoxetine in pharmaceutical formulations

Two different analytical methods for the quality control of fluoxetine in commercial formulations have been developed and compared: a spectrofluorimetric method and a capillary zone electrophoretic (CZE) method. The fluorescence emission values were measured at lambda=293 nm when exciting at lambda=230 nm. The CZE method used an uncoated fused-silica capillary and pH 2.5 phosphate buffer as the background electrolyte. The extraction of fluoxetine from the capsules consisted of a simple one-step dissolution with methanol/water, filtration and dilution. Both methods gave satisfactory results in terms of precision; the best results were obtained for the electrophoretic method, with RSD% values always lower than 2.0%. The accuracy was assessed by means of recovery studies, which gave very good results, between 97.5 and 102.6%. Furthermore, both methods also have the advantage of being very rapid.

Photochemistry of iron-porphyrin complexes. Biomimetics and catalysis

Abstract An intramolecular electron transfer can occur in iron porphyrin complexes that are irradiated with light of suitable wavelength corresponding to axial ligand-to-metal charge transfer transitions. This process leads to the reduction of Fe(III) to Fe(II) and to the oxidation of the axial ligand to a radical species. The efficiency of the photoredox process is increased in the presence of species able of trapping the ferrous complex and/or the radical in competition with the back electron transfer process. Photoredox reactions of iron porphyrins and heme-proteins (cytochrome c) are examined in the framework of the fundamental role of electron transfer processes in biological systems. The products of the primary photoprocess can induce reactions leading to reduction or oxidation of various substrates with catalytic efficiency. This biomimetic aspect of the photoredox behavior of iron porphyrins is pointed out examining the results obtained in investigations concerning the iron-porphyrin based photoreduction of CCl4 in homogeneous solution, and photooxygenation of alkanes in both homogeneous and heteterogeneous systems.

Photo-assisted chlorination of cycloalkanes with iron chloride heterogenized with Amberlite

Photoexcitation under mild temperature and pressure conditions of FeCl4- heterogenized with Amberlite causes the conversion of several cycloalkanes to the corresponding monochlorinated products with selectivity higher than 95%.

Iron meso-tetra(2,6-dichlorophenyl)porphyrin as a very efficient catalyst for the photoreduction of carbon tetrachloride by alcohols

The ability of Fe(tdcpp)(CI), iron meso-tetra(2,6-dichlorophenyl)porphyrin chloride, to act as an efficient catalyst for photoredox reactions is shown by both the unusually high FeIII photoreduction quantum yield and the high recycle numbers obtained in the catalytic photoreduction of carbon tetrachloride by alcohols.

Photochemical and Photocatalytic Properties Iron-Tetra-Aryl-Porphyrins

We examine here the photoredox properties of a series of iron-tetra-aryl-porphyrins to test their capability of working as biomimetic catalysts in photoinduced oxygen and electron transfer processes.