Evaluation of injection force of three insulin delivery pens.

OBJECTIVE: Reduced injection force is among the modifications to the Next Generation FlexPen (NGFP). This force was compared with two other prefilled pens: SoloStar (SS) and KwikPen (KP). RESEARCH DESIGN/METHODS: The injection force of the pens was measured, with either a BD Micro-Fine 31G thin-wall needle, or a NovoFine 32G Tip extra thin wall needle attached. Pens of each type were tested with both needles, during injection of 20 U insulin, at speeds 3.3, 5 and 8.3 mm/s. RESULTS: NGFP had a significantly (p < 0.05) lower mean injection force than SS or KP, at all injection speeds, with both needles. Injection forces (mean +/- s.d.) with NGFP and the BD Micro-Fine() 31G thin-wall needle were: 8.1 +/- 0.7, 10.7 +/- 1.4 and 15.6 +/- 0.9 N at the three speeds, respectively. For SS, the corresponding values were: 9.2 +/- 0.5, 13.3 +/- 0.8 and 20.7 +/- 2.4 N. For KP they were: 12.5 +/- 1.6, 16.9 +/- 1.2 and 24.5 +/- 2.6 N. Attached to the NovoFine 32G Tip extra thin wall needle, the NGFP injection forces were: 5.7 +/- 0.4, 8.2 +/- 0.7 and 12.7 +/- 0.5 N; with SS were: 6.7 +/- 0.3, 10.4 +/- 2.1 and 16.3 +/- 1.1 N; and with KP were: 9.1 +/- 1.3, 13.1 +/- 0.8 and 21.6 +/- 2.0 N. The injection force with NGFP was 12 - 25% lower compared with SS and 35 - 41% lower compared with KP. CONCLUSIONS: This study shows that NGFP has a significantly lower injection force than SS or KP.

[Studies on the method of sterilization with ethylene oxide gas. 2. Residual EO gas on sterilized objects].

Ethylene oxide gas (EO gas) adsorbed onto sterilized objects was quantitated in an effort to take a safety measure against residual EO gas following its use in sterilization. We measured residual amounts of EO gas adsorbed onto laboratory wares, small medical tools and appliances just after post-sterilization airation to examine whether they were rendered entirely free from EO gas by the process. The results led us to arrive at the following conclusions: 1. EO gas was recognized to remain on sterilized objects even after allowing them to stand for about 16 hours following airation. 2. The amount of residual EO gas was smaller on metallic products and larger on rubber products (notably rubber gloves). An exceedingly high concentration of EO gas was noted to remain on a tooth-brush, among other plastic materials. These facts seem to indicate that the amount of residual EO gas is closely related to the texture and shape of materials to be sterilized. 3. As regards the potential toxicity of residual EO gas. However, their sensitivity was proved to be questionable, judgment on a result being subject to considerable individual variations. 4. Nevertheless, it is incontestable that these devices can at least provide a rough estimate of unavailing since monitoring by direct measurement of residual EO gas is virtually infeasible from a practical point of view.