title: A study of photostability and compatibility of the anti-chagas drug Benznidazole with pharmaceutics excipients.
abstract: Abstract Context: Benznidazole (BNZ) is an antiparasitic with trypanocidal properties for the etiological treatment of Chagas disease since 1973. Monitoring the stability of this drug is one of the most effective methods of assessment, forecasting and prevention of problems related to quality product.
  
  
  OBJECTIVE
  To investigate the direct and indirect photodegradation of BNZ and to evaluate the interference of the excipients used in the forms dosage solid as well as to shed light on the chemical structure of the degradation products obtained.
  
  
  METHODS
  To perform this work we adopted the "ICH Harmonised Tripartite Guideline: Photostability Testing of New Drug Substances and Products Q1B" (Guideline Q1B). We used benzonidazole (BNZ) (N-benzil-2-(2-nitroimidazol-1-il) acetamide) (LAFEPE®, Recife, Brazil) and various excipients; beyond high-performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and mass spectrometry/mass spectrometry (MS/MS). The indirect photodegradation of BNZ was carried out using physical mixtures with 13 pharmaceutical excipients commonly used in the preparation of solid dosage forms.
  
  
  RESULTS
  HPLC and MS/MS techniques were selected for the identification of two photoproducts (PPs) and photoreactions found in direct and indirect tests with the microcrystalline cellulose, considered a critical excipient.
  
  
  CONCLUSIONS
  Despite variations in the infrared spectrometry, differential scanning calorimetry and differential thermogravimetry curves, these techniques are not conclusive since the study of photodegradation of the drug caused decay of 30%, according to the ICH.
  
  
  CONCLUSIONS
  The results show that BNZ only undergoes direct photodegradation, since no new PPs were found for a combination of the drug and excipients.
authors.affiliation: Laboratório de Tecnologia dos Medicamentos, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Rua Prof. Arthur de Sá, s/n, Cidade Universitária , Recife, PE , Brazil .
authors.forename: Fabiana L A
authors.initials: FL
authors.lastname: Santos
authors.forename: Larissa A
authors.initials: LA
authors.lastname: Rolim
authors.forename: Camila B M
authors.initials: CB
authors.lastname: Figueirêdo
authors.forename: Magaly A M
authors.initials: MA
authors.lastname: Lyra
authors.forename: Monize S
authors.initials: MS
authors.lastname: Peixoto
authors.forename: Leslie R M
authors.initials: LR
authors.lastname: Ferraz
authors.forename: José L
authors.initials: JL
authors.lastname: Soares-Sobrinho
authors.forename: Ádley Antonini
authors.initials: ÁA
authors.lastname: Neves de Lima
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Lima Leite
authors.forename: Pedro José
authors.initials: PJ
authors.lastname: Rolim Neto
mesh_terms: D014355:Chagas Disease / Q000188:drug therapy; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use; D009593:Nitroimidazoles / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use; D010782:Photolysis / Q000528:radiation effects; D014344:Trypanocidal Agents / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use
chemical_list: D005079:Excipients; D009593:Nitroimidazoles; D014344:Trypanocidal Agents; C009999:benzonidazole
keywords: Benznidazole; Chagas disease; HPLC-MS/MS; degradation product; photodegradation