title: Development and validation of a dissolution test for lodenafil carbonate based on in vivo data.
abstract: BACKGROUND
  Lodenafil carbonate is a phosphodiesterase type 5 inhibitor used for the treatment of erectile dysfunction. Currently, there is no dissolution test reported for lodenafil carbonate and this drug is not listed in any pharmacopoeia.
  
  
  OBJECTIVE
  The present study focused on the development and validation of a dissolution test for lodenafil carbonate tablets, using a simulated absorption profile based on in vivo data.
  
  
  METHODS
  The appropriate conditions were determined after testing sink conditions. Different conditions as medium, surfactant concentration and rotation speed were evaluated. The percentage of dose absorbed was calculated by deconvolution, using the Wagner-Nelson method.
  
  
  RESULTS
  According to the obtained results, the use of 0.1 M HCl + 1.5% SLS (900 mL, at 37 + 0.5 °C) as the dissolution medium, paddles at 25 rpm were considered adequate. The samples were quantified by UV spectroscopy at 295 nm and the validation was performed according to international guidelines. The method showed specificity, linearity, accuracy and precision, within the acceptable range. Kinetics of drug release was better described by the first-order model.
  
  
  CONCLUSIONS
  The proposed dissolution test can be used for the routine quality control of lodenafil carbonate in tablets.
authors.affiliation: Faculty of Pharmacy, Federal University of Rio Grande do Sul , Porto Alegre - RS , Brazil.
authors.forename: Cristiane Franco
authors.initials: CF
authors.lastname: Codevilla
authors.forename: Tamara dos Santos
authors.initials: Tdos S
authors.lastname: Castilhos
authors.forename: Carolina Araújo
authors.initials: CA
authors.lastname: Cirne
authors.forename: Pedro Eduardo
authors.initials: PE
authors.lastname: Froehlich
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Bergold
mesh_terms: D002254:Carbonates / Q000737:chemistry*; D007172:Erectile Dysfunction / Q000188:drug therapy; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D058986:Phosphodiesterase 5 Inhibitors / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000737:chemistry; D013607:Tablets
chemical_list: D002254:Carbonates; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011743:Pyrimidines; D013501:Surface-Active Agents; D013607:Tablets; C532120:lodenafil carbonate