About
Contact
Help
Sending publications
How to publish
Advanced Search
View Item 
  •   Home
  • Facultad de Ciencias Químicas y Farmacéuticas
  • Artículos de revistas
  • View Item
  •   Home
  • Facultad de Ciencias Químicas y Farmacéuticas
  • Artículos de revistas
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Browse byCommunities and CollectionsDateAuthorsTitlesSubjectsThis CollectionDateAuthorsTitlesSubjects

My Account

Login to my accountRegister
Biblioteca Digital - Universidad de Chile
Revistas Chilenas
Repositorios Latinoamericanos
Tesis LatinoAmericanas
Tesis chilenas
Related linksRegistry of Open Access RepositoriesOpenDOARGoogle scholarCOREBASE
My Account
Login to my accountRegister

Photophysical and photochemical behavior of nimodipine and felodipine

Artículo
Thumbnail
Open/Download
IconJPP 2007. LETELIER.pdf (552.1Kb)
Publication date
2007-06-10
Metadata
Show full item record
Cómo citar
Pizarro Urzúa, Nancy A.
Cómo citar
Photophysical and photochemical behavior of nimodipine and felodipine
.
Copiar
Cerrar

Author
  • Pizarro Urzúa, Nancy A.;
  • Günther Sapunar, Germán;
  • Núñez Vergara, Luis;
Abstract
A different photophysical and photochemical behavior has been found between two second generation antihypertensive 1,4-dihydropyitidines (1,4-DHPs), felodipine and nimodipine. While nimodipine was observed as being more reactive and photolabile in excited state, felodipine showed a major reactivity in its ground state towards an electrophilic transient species like singlet oxygen. Nimodipine had a photodegradation quantum yield of 2.34 x 10(-4) in deaereated acetonitrile and 1.81 x 10(-2) in deaereated ethanol. The values of the photodegradation quantum yields in aereated solutions were similar. However, felodipine is less photolabile than nimodipine, with a photodegradation quantum yield changing from 1.4 x 10(-5) to 7 x 10(-6) in the same solvents, probably a consequence of a lowered stability of the zwitterion radical involved in the formation of the photoproduct. In addition, nimodipine and felodipine were able to generate singlet oxygen with quantum yields of 0.085 and 0.003 in benzene, respectively. The results show that tested 1,4-DHPs behave as relatively good scavengers of excited oxygen, with overall rate constant values for nimodipine ranging from 0.38 x 105 M-1 s(-1) in chloroform to 9.73 x 10(5) M-1 s(-1) in N,N-dimethylformamide. On the other hand, the rate constants for felodipine ranged from 0.44 x 105 M-1 s(-1) in benzene to 19.5 x 10(5) M-1 s(-1) in N,N-dimethylacetaniide. In conclusion, the present results indicate that it is difficult to discriminate which specie is responsible for the photoallergic and phototoxic effects previously reported for these drugs, because these effects could be attributed to the participation of zwitterionic radicals in the process of photodegradation and/or its ability to generate singlet oxygen.
Identifier
URI: https://repositorio.uchile.cl/handle/2250/120471
ISSN: 1010-6030
Quote Item
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 189(1):23-29
Collections
  • Artículos de revistas
xmlui.footer.title
31 participating institutions
More than 73,000 publications
More than 110,000 topics
More than 75,000 authors
Published in the repository
  • How to publish
  • Definitions
  • Copyright
  • Frequent questions
Documents
  • Dating Guide
  • Thesis authorization
  • Document authorization
  • How to prepare a thesis (PDF)
Services
  • Digital library
  • Chilean academic journals portal
  • Latin American Repository Network
  • Latin American theses
  • Chilean theses
Dirección de Servicios de Información y Bibliotecas (SISIB)
Universidad de Chile

© 2020 DSpace
  • Access my account