title: Dose accuracy and durability of the NovoPen 4 insulin delivery device before and after simulation of 5 years of use and under various stress conditions.
abstract: OBJECTIVE
  The dose accuracy of the NovoPen 4 (Novo Nordisk A/S, Bagsvaerd, Denmark) insulin delivery device was evaluated before and after simulation of 5 years of use and under conditions of mechanical and temperature stress.
  
  
  METHODS
  To simulate 5 years of use of the NovoPen 4, > or =5475 injections were performed automatically, corresponding to 3 daily injections for 5 years. Accuracy in the delivery of 1-, 30-, and 60-U insulin doses before and after simulation of 5 years of use was assessed over the in-use temperature range (5 degrees C-40 degrees C [41 degrees F-104 degrees F]). The durability and dose accuracy of the NovoPen 4 were also assessed after exposure to extremes of temperature (-40 degrees C and 70 degrees C), high relative humidity (95% RH), and mechanical challenges (freefall from 1.5 m at ambient temperature and from 1 m at 5 degrees C, 40 degrees C, and 95% RH).
  
  
  RESULTS
  The dose accuracy of the NovoPen 4 before and after 5 years of simulated use was within International Organization for Standardization 11608-specified limits for all doses studied. Dose accuracy remained within specifications for all doses after exposure to variations in temperature and humidity, and after freefall.
  
  
  CONCLUSIONS
  The NovoPen 4 exhibited dose accuracy before and after simulation of 5 years of use, across a wide range of temperature and humidity conditions, and after mechanical challenges.
authors.affiliation: Novo Nordisk A/S, Hilleroed, Denmark. CMK@novonordisk.com
authors.forename: Carsten M
authors.initials: CM
authors.lastname: Kristensen
authors.forename: Morten
authors.initials: M
authors.lastname: Donsmark
mesh_terms: D016503:Drug Delivery Systems / Q000295:instrumentation*; D004867:Equipment Design; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D017743:Equipment Reuse; D006813:Humidity; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007267:Injections; D007328:Insulin / Q000008:administration & dosage*; D008422:Materials Testing; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin