title: Reduction of the "burst release" of copper ions from copper-based intrauterine devices by organic inhibitors.
abstract: BACKGROUND
  The copper intrauterine device is a contraceptive method that is based on the release of copper ions from a copper wire. Immediately after insertion, the dissolution of copper in the uterine fluid is markedly higher ("burst release") than that necessary for contraception action, leading to a variety of harmful effects.
  
  
  METHODS
  Pretreatments with organic compounds [thiourea (TU) and purine (PU), 10(-4)-10(-2) M concentration range, 1- and 3-h immersion times] were tested. The dissolution of copper with and without pretreatments in TU and PU solutions was analyzed by conventional electrochemical techniques and surface analysis.
  
  
  RESULTS
  Pretreatments in PU solutions reduced the initial corrosion rate of copper in simulated uterine solutions, with inhibitory efficiencies that depend on the PU concentration and on the immersion time assayed. Inhibitory efficiency values higher than 98% for pretreatments with ≥10(-3) M PU were found. Conversely, after TU pretreatments, a high copper release was measured.
  
  
  CONCLUSIONS
  It was concluded that 10(-3) M PU pretreatment is a promising strategy able to reduce the "burst release" of copper and to ensure contraceptive action.
authors: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT-CONICET La Plata), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC 16, Suc. 4 (1900) La Plata, Argentina.
authors: Florencia
authors: F
authors: Alvarez
authors: Patricia L
authors: PL
authors: Schilardi
authors: Monica Fernández Lorenzo
authors: MF
authors: de Mele
mesh_terms: D003300:Copper / Q000032:analysis / Q000737:chemistry*; D003343:Corrosion; D055664:Electrochemical Techniques; D007435:Intrauterine Devices, Copper / Q000009:adverse effects*; D011687:Purines / Q000737:chemistry*; D013890:Thiourea / Q000737:chemistry*
chemical_list: D011687:Purines; D003300:Copper; D013890:Thiourea; C030985:purine