Injection force of reusable insulin pens: Novopen 4, Lilly Luxura, Berlipen, and ClikSTAR.
BACKGROUND
Insulin pen devices are used by approximately half of insulin users worldwide. The injection force of insulin pens is a key element in their design. This study aimed to demonstrate that the sanofi-aventis reusable ClikSTAR® (CS) pen has an improved injection force over existing insulin pens.


METHODS
The injection force of four reusable insulin pens--Novopen® 4 (NP4; Novo Nordisk), Luxura® (LL; Eli Lilly and Co.), Berlipen® (BP; Haselmeier GmbH), and CS (sanofi-aventis)--was tested in a laboratory setting. Injection force was tested using two methods: six dispense rates between 6 and 24.66 U/s (constant volume flow rate) and constant button speeds of 4 and 8 mm/s.


RESULTS
The CS required a lower mean injection force versus NP4, LL, and BP at both doses and all dispense rates. Mean injection force was 45%, 126%, and 60% higher for NP4, LL, and BP versus CS, respectively (p < .05 for each of the comparisons), for a flow rate of 6 U/s at 60 U dose. Mean injection force in all pens increased with the dispense rate, but the injection force remained significantly lower for CS versus all other pens (p < .05). The injection force for CS was significantly lower for 60 U at 10 and 17.03 U/s than for 80 U.


CONCLUSIONS
The study demonstrated that CS pens require a lower injection force at a wide range of different injection speeds than other reusable insulin pens. This is an important benefit for patients with diabetes, especially those with limited dexterity.
LWS Risk Management Consult, Brannenburg, Germany. arnd.friedrichs@lwsgroup.com
Arnd
A
Friedrichs
Volker
V
Korger
Steffen
S
Adler
D003920:Diabetes Mellitus / Q000188:drug therapy*; D016503:Drug Delivery Systems; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007279:Injections, Subcutaneous / Q000295:instrumentation; D007328:Insulin / Q000008:administration & dosage*
D007004:Hypoglycemic Agents; D007328:Insulin