Evaluating the Impact of Human Factors and Pen Needle Design on Insulin Pen Injection

Abstract

Background: Limited published data exists quantifying the influence of human factors (HF) and pen needle (PN) design on delivery outcomes of pen injection systems. This preclinical in vivo study examines the impact of PN hub design and applied force against the skin during injection on needle penetration depth (NPD). Method: To precisely locate injection depth, PN injections (20 µl; 2 IU, U-100 volume equivalent) of iodinated contrast agent were administered to the flank of Yorkshire swine across a range of clinically relevant application forces against the skin (0.25, 0.75, 1.25, and 2.0 lbf). The NPD, representing in vivo needle tip depth in SC tissue, from four 32 G × 4 mm PN devices (BD Nano™ 2nd Gen and three commercial posted-hub PN devices; n = 75/device/force, 1200 total) was measured by fluoroscopic imaging of the resulting depot. Results: The reengineered hub design more closely achieved the 4 mm target NPD with significantly less variability (P = .006) than commercial posted-hub PN devices across the range of applied injection forces. Calculations of IM (intramuscular) injection risk completed through in silico probability model, using NPD and average human tissue thickness measurements, displayed a commensurate reduction (~2-8x) compared to conventional PN hub designs. Conclusions: Quantifiable differences in injection depth were observed between identical labeled length PN devices indicating that hub design features, coupled with aspects of variable injection technique, may influence injection depth accuracy and consistency. The reengineered hub design may reduce the impact of unintended individual technique differences by improving target injection depth consistency and reducing IM injection potential.

Insulin Injection Practices in a Population of Canadians with Diabetes: An Observational Study

“…3 a as a reference point was the image depicting the most significant application pressure. Proper technique indicates the needle hub should be visible and to avoid indenting the skin when injecting to reduce the risk of intramuscular injection [ 5 , 29 ]. Pen needle hub design, in addition to needle length and injection technique, may help with mitigating excessive user-applied injection force [ 29 , 30 ].…”

“…Structured training and the use of new-generation pen needles can help improve injection technique, leading to significant HbA1c reductions and decreased rates of lipohypertrophy [34,43]. Technological advances in needle design have observed that a 4 mm pen needle injected at a 90°angle results in optimal needle depth penetration, therefore reducing the risk of intramuscular injections [29]. New-generation pen needles have also been associated with more positive patient reviews and improved ease of use [30], and in general, shorter needles are the preferred choice for most patients [25].…”

“…New-generation pen needles have also been associated with more positive patient reviews and improved ease of use [30], and in general, shorter needles are the preferred choice for most patients [25]. Pen needle hub design may also support proper injection force [29,30].…”

Bruising—An Ignored Issue?

“…One manufacturer (Becton Dickinson) has recently redesigned this hub from a dome to a tip that looks more like a ring. 5 The new hub design aims to reduce the impact of variable injection techniques by dispersing insertion forces across a re-engineered, contoured, and expanded surface area. 5 The design of the hub enables a more comfortable insulin application with a full-length needle penetration regardless of application force.…”

User experiences with second-generation 32-gauge × 4 mm vs. thinner comparator pen needles: prospective randomized trial

“…For these reasons, a 32 G extra-thin-wall, 5-bevel cannula PN has been re-engineered with a contoured hub with expanded surface area to improve the injection experience and injection depth consistency 21,[25][26][27] . The aim of this investigation, conducted as two separate studies, was to compare user experiences with this redesigned, second generation 32 G Â 4 mm PN (investigational BD 32 G PN: BD Nano i 2nd Gen, also known as BD Nano PRO) versus four thinner and similar length, commercially available PNs (33 G Â 4 mm, 34 G Â 4 mm, and 34 G Â 3.5 mm).…”