2020 Volume 9 Issue 1 Pages 135-142
Dedicated needles for pen-shaped self-injectable syringes for insulin or GLP-1 receptor activation (hereinafter referred to as injection needles) have been developed with the aim to reduce pain during injections. According to a study based on patients’ clinical experiences, a tendency has been reported that “the thinner and shorter the needles, the less painful patients feel”. In recent years, NANOPASS® Jr. 34G3mm with the needle length of 3mm (Terumo: TN34GT-J3) was launched, which we put to a fundamental test against the old tapered needles of NANOPASS® II 34G4mm needle (Terumo: TN34GT4). As a result, it was found that, while the piercing resistance was similar, the injection and flow path resistances of TN34GT-J3 were less than those of TN34GT4, with the strength evaluated from the deflection width and the number of bending times until breaking point was greater for TN34GT-J3. From these results, we noted that TN34GT-J3 is no inferior to TN34GT4 in any structural measurements and usable fundamentally as well as TN34GT4. Furthermore, with its shorter needle length potentially reducing intramuscular injection risks, it is considered useful for such patients with less subcutaneous fat at injection sites as children and lean patients.
