A review with 310 references. Photochemical degradation is likely to be an important loss mechanism for many pharmaceutical pollutants in surface waters. This review summarizes the current knowledge of the photochemical behavior of pharmaceuticals and highlights the use of the fundamental photochemistry and phototoxicity literature to help understand and predict the aquatic fate of pharmaceuticals. Naproxen and diclofenac are shown to exemplify the idea that photochemical behavior obtained from fundamental photochemistry studies can be related to environmental conditions. There are, however, numerous compounds that have been found in environmental matrices for which no photochemistry data relatable to environmental conditions are available. It will be necessary to combine the results available in the large body of fundamental photochemistry and phototoxicity literature with laboratory and field experiments designed to determine direct and indirect photolysis rates and to identify photoproducts. This course will lead to a thorough understanding of the role of photodegradation on the fate and impact of pharmaceutical pollutants.

Photodegradation of pharmaceuticals in the aquatic environment: A review

Determination of nifedipine using nanostructured electrochemical sensor based on simple synthesis of Ag nanoparticles at the surface of glassy carbon electrode: Application to the analysis of some real samples

Photostability of Drugs and Drug Formulations, Second Edition

1. Lipid peroxidation in rat brain slices was induced by Fe+3/ascorbate. 2. Brain lipid peroxidation, as measured by malondialdehyde formation, was inhibited by all the tested nitro aryl 1,4-dihydropyridine derivatives over a wide range of concentrations. The time-course antioxidant effects of the most representative agents were assessed. On the basis of both time-course and IC50 experiments the tentative order of antioxidant activity on rat brain slices could be: nicardipine>nisoldipine> (R,S/S,R)-furnidipine > (R,R/S,S)-furnidipine>nitrendipine>nimodipine> nifedipine. 3. 1,4-Dihydropyridine derivatives that lack of a nitro group in the molecule (isradipine, amlodipine) also inhibited lipid peroxidation in rat brain slices but at higher concentrations than that of nitro-substituted derivatives. 4. All the tested nitroso aryl derivatives [2,6-dimethyl-4-(2-nitrosophenyl)-3,5-pyridinedicar. boxylic acid dimethyl ester (NTP), nitrosotoluene, nitrosobenzene] were more potent inhibitors of lipid peroxidation than were the parent nitro compounds. In conclusion, on the basis of the IC50 values determined, the rank order of antioxidant potency for these derivatives can be established as: ortho-nitrosotoluene>NTP>nitrosobenzene.

Antioxidant Effects of 1,4-Dihydropyridine and Nitroso Aryl Derivatives on the Fe+3/Ascorbate-Stimulated Lipid Peroxidation in Rat Brain Slices

The electrochemical behavior of several calcium antagonists of the dihydropyridine family has been investigated in aqueous buffered solution using a glassy carbon electrode. Both oxidation of the dihydropyridine ring and the reduction of the nitro or benzoxadiazole moiety are observed using cyclic voltammetry and the shape of the voltammograms depending on the initial scan direction. Each process may interfere with the other. The single reduction peak corresponds to a four‐electron transfer giving rise to the hydroxylamine. Reversing the scan leads to the nitroso derivative, its reversibility depends on the 2‐ or 3‐position of the nitro group. Oxidation of the dihydropyridine ring proceeds through a two‐electron exchange. However, nicardipine, which possesses a dialkylbenzylamine side chain, exhibits two additional peaks; the first due to the methoxylation of the side chain, and the second attributed to the oxidative chlorination of this moiety. Potentials are pH dependent. A general EC mechanism is proposed for the overall process. Copyright © 1992 VCH Publishers Inc.

Cyclic voltammetric study of some calcium antagonist dihydropyridines in aqueous medium

Nifedipine: Differential pulse polarography and photodecomposition.

A polarographic study of the photodegradation of nitrendipine.

GC/MS and DART-MS as complementary methods for investigating the effects of weathering on chemical profiles of ignitable liquids: A case study for paint thinner

S. Perna

Papers

Nifedipine: Differential pulse polarography and photodecomposition.

A polarographic study of the photodegradation of nitrendipine.

GC/MS and DART-MS as complementary methods for investigating the effects of weathering on chemical profiles of ignitable liquids: A case study for paint thinner

Evaluation of Mass Spectrometric Methods for Screening Polycyclic Aromatic Hydrocarbons in the Particulate Phase of Wildfire/Biomass Smoke