Use of jet insulin injection in diabetes mellitus therapy

Assessment of the biological performance of the needle-free injector INJEX using the isolated porcine forelimb

BACKGROUND

The development and utilization of novel needle-free injection devices in order to minimize needle stick injuries make increasing demands for suitable assay systems, which reflect the physiological situation in humans as close as possible.

OBJECTIVES

It was therefore the goal of the present study to test the biological performance of a needle-free injector (INJEX) by the use of porcine skin as a model with a high predictive value for the feasibility in humans because of its close similarity to human skin.

METHODS

In order to use porcine skin in the context of the underlying tissues, the isolated porcine forelimb was chosen as an assay model for use with the INJEX injector. Ink or the fluorescent dye fluorescein-isothiocyanate was injected and the penetration depth was determined metrically and dye distribution histologically. To assess the resorption of heparin, needle injection was compared with needle-free injection in a perfused limb model.

RESULTS

Increasing amounts of ink increasingly penetrated into subcutaneous tissue layers in a cone-shaped manner mainly following lead structures. Penetration was hampered by skin thickness and by the deep muscle fascia, which served as a penetration barrier. Resorption of heparin was similar irrespective of injection by the use of a needle or the INJEX device.

CONCLUSIONS

The isolated porcine forelimb serves as a versatile tool for the assessment of the biological performance of needle-free injection devices such as INJEX. Further studies are necessary to correlate the model for drug delivery in humans.

New Way to Deliver Fluids: Endoscopic Jet Injection Into the Beagle Prostate

PURPOSE

Local therapy of the prostate could have a role in the treatment of benign prostatic hyperplasia as well as prostate cancer. Endoscopic jet injection could simplify these treatments. We evaluated the tissue effects of endoscopic jet injection in an animal model.

MATERIALS AND METHODS

An endoscopic jet injector was developed. In 12 beagle dogs the prostate was injected with single shot and continuous mode jet injection. Macroscopic and histological analysis was performed 0, 2 and 14 days after jet injection.

RESULTS

Jet injection allowed complete penetration of the beagle prostate. The single shot technique resulted in only minimal tissue effects. However, the continuous mode led to major tissue damage, even complete aseptic necrosis, in the injected area.

CONCLUSIONS

A new method for endoscopic application of fluids is described. Depending on the jet injection technique it could be used to apply pharmaceutical agents or plasmids, and/or induce aseptic necrosis.

Delivery of insulin by jet injection: recent observations

Medi-Ject Corporation (now Antares Pharma, Inc.) has been providing delivery devices for the needle-free administration of insulin for over 25 years. This study was one of the final steps in the development and premarket evaluation of Medi-Ject's newest needle-free system, the Medi-Jector Vision. This study was conducted to evaluate the performance of this device in the hands of experienced jet injection users in a home environment. Diabetic subjects currently using a needle-free device for the administration of their insulin were studied. Subjects used the new Medi-Jector Vision for all of their insulin administration during the course of the study. Insulin was injected on schedule and at doses consistent with their standard of practice as directed by their health care provider. All subjects were required to document each injection in a daily diary. Study subjects utilized all common insulin types (rapid, regular, intermediate, and long acting), and injections were administered in all of the common injection sites (arms, thighs, abdomen, and buttocks). Once subjects optimized the system to the most appropriate orifice size based on completeness of injection, average completeness percentages were greater than 94% for all orifice sizes. Most patients using the new Medi-Jector Vision in the home were able to manage their insulin therapy without significant complication. We conclude that the jet delivery of insulin with the new Medi-Jector Vision is well accepted by people with diabetes and offers a reliable alternative to the use of needles.

Painless intravenous catheterization by intradermal jet injection of lidocaine: a randomized trial

STUDY OBJECTIVE

To compare efficacy and cost of lidocaine cutaneous anesthesia by two jet injectors to routine needle infiltration for pain relief of intravenous (i.v.) catheterization, hypothesizing that jet injection of lidocaine is less painful than its needle infiltration.

DESIGN

Randomized, prospective, controlled trial.

SETTING

University hospital outpatient surgical unit.

PARTICIPANTS

75 surgical patients ASA I and II.

INTERVENTIONS

Three groups of 25 patients each were given intradermal lidocaine anesthesia via conventional 25-gauge needle/syringe; by MedEJet or Biojector jet injector prior to IV catheterization with an 18-gauge Jelco catheter.

MEASUREMENTS AND MAIN RESULTS

Visual analogue pain scores (VAS) (0 = no pain, 10 = intolerable pain) and subjective pain intensity scores (PIS) (0 = not painful, 4 = intolerable pain) at lidocaine application and at i.v. catheterization, were recorded. Cost assessment of each method was made. At local anesthetic application, no pain by proportion of VAS = 0 with MedEJet: 25/25 (confidence interval [CI]: 0.868, 0.999) and Biojector: 24/25 (CI 0.804, 0.991) was noted, but-22 of 25 patients experienced pain with needle administration: (with VAS = 0; 3/25 [CI: 0.044, 0.302]) (posterior probability [PP] > 0.999). The corresponding VAS scores (means +/- SD) were 0.00 +/- 0.00, 0.04 +/- 0.20, and 2.4 +/- 2.23 (p < 0.001). No pain by proportion of PIS = 0 with MedEJet: 25/25 (CI: 0.868, 0.999 and Biojector: 23/25 (0.749, 0.976) was noted, but pain in 20/25 was felt with the needle: 5/25 (CI: 0.090, 0.394) (PP > 0.999). The corresponding PIS scores were 0.00 +/- 0.00, 0.16 +/- 0.55, and 1.24 +/- 1.00 (p < 0.001). At i.v. catheterization, no pain by proportion of VAS = 0 with MedEJet: 22/25 (CI: 0.698, 0.956) or Biojector: 21/25 (CI: 0.651, 0.934) was noted; but pain in 19/25 with needle administration was experienced: 6/25 (CI: 0.116, 0.436) (PP > 0.999). The corresponding scores were 0.12 +/- 0.33, 0.44 +/- 0.20, and 1.64 +/- 1.50 (p < 0.001). No pain by proportion of PIS = 0 with MedEJet: 24/25 (CI: 0.804, 0.991) or Biojector: 24/25 (CI: 0.804, 0.991) was noted, but pain was apparent in 12/25 with needle administration: 13/25 (CI: 0.334, 0.701) (PP > 0.999). The corresponding scores were 0.00 +/- 0.00, 0.00 +/- 0.00, and 0.76 +/- 0.88 (p < 0.001). Cost per application: MedEJet = $0.13; needle/syringe = $0.50; Biojector = $0.94.

CONCLUSIONS

Almost completely painless i.v. catheterization was carried out by jet injection of lidocaine, but needle infiltration produced discomfort or pain and did not significantly reduce discomfort or pain at the i.v. needle insertion.

Recent approaches in insulin delivery

Insulin remains indispensable in the management of diabetes mellitus since its discovery in 1921. The foreignness of early available porcine and bovine insulin led to the development of human insulin by transpeptidation and biosynthesis in microorganisms. Needle phobia and stress of multiple daily injections led to the investigation and exploitation of all promising routes, ranging from nasal to rectal, by a wide variety of devices and delivery systems. This article describes the development of human insulin, various routes for delivery of insulin (including oral, nasal, buccal, rectal, and pulmonary), and various devices for regulated, safe, and convenient insulin delivery. The article reviews some recent advances in insulin delivery such as the bioresponsive and self-regulated insulin delivery system.

Evaluation of the insulin jet injector as a potential source of infection

In recent years jet injection of insulin has been widely used by patients with diabetes mellitus. Jet injectors may become contaminated by bacteria because of repeated use without cleaning; cleansing every 2 weeks is recommended. We investigated the occurrence of bacterial contamination by culturing jet injectors in everyday use by 19 patients with diabetes. Swabs from the interior chambers were cultured on blood agar plates. Only one of 20 cultures yielded bacterial growth, and the organism recovered was a presumed contaminant that could not be identified as any common pathogen. No study patient, nor any of more than 70 patients whom we instructed in jet injection, showed any clinical evidence of infection attributable to jet injector use. Jet injectors are unlikely to become colonized by bacteria or to cause infection in patients using them for insulin administration. The low rate of colonization may be due to the antibacterial preservatives added to commercial preparations of insulin. Additional data based on larger numbers of patients would be useful in further clarifying the risk of infection associated with jet injectors.

The application of insulin using the jet injector DG-77

To avoid soreness and psychic stress following insulin injections by needle and syringe, the new jet injector DG-77 was used. It is a portable percutaneous pressure device with a spring, simple to operate which can be used to apply two different types of insulin. Thirty type 1 and type 2a diabetic patients participated in the study (10 females, 20 males). Insulin was applied using a needle and the DG-77 device in the same region of the body. A standardized questionnaire was compiled concerning simplicity of application, soreness, wish to possess the device and the possibility of acquiring it. The results obtained regarding the type of application were as follows: traditional way: glycemia: at 07(00)-8.5, 10(00)-10.5, 13(00)-7.4 mmol/l; insulinemia: at 07(00)-7.5, 10(00)-20.2, 13(00)-21.0 mU/l; jet injector: glycemia - at 07(00)-8.4, 10(00)-10.4, 13(00)-8.4 mmol/l; insulinemia: at 07(00)-2.8, 10(00)-12.3, 13(00)-20.0 mU/l, which was not statistically significant; for glycemia: at 10(00), t = 0.110, p greater than 0.05, at 13(00), t = 1.88, p greater than 0.05, and for insulinemia at 10(00), t = 0.82, p greater than 0.05, and at 13(00), t = 1.23, p greater than 0.05.

IN CONCLUSION

1) blood glucose and insulin control with the jet injector administration of insulin was equally successful as with the standard insulin application; 2) incidence of hematoma was not significant; 3) eighty-five percent of patients prefer the injector due to its simplicity of application, reduced soreness and would wish to possess the device.

Trigger point injections vs. jet injection in the treatment of myofascial pain

Trigger point injections using dilute solutions of local anesthetic agents have proved effective for many patients with myofascial pain. The treatment itself, however, can produce severe pain and may occasionally be associated with complications. It was determined in this study that a local anesthetic solution administered by jet injection in the area of myofascial trigger points was capable of providing short-term pain relief equal to conventional trigger point injections using a hypodermic needle and syringe. The jet injector system produced significantly less pain during treatment than conventional trigger point injections and therefore was preferred by most subjects having the opportunity to compare both forms of treatment.

Alternative method of intercostal blockade. A preliminary study of the use of an injector gun for intercostal nerve blockade

An injector gun of the type developed for vaccinations was used to perform intercostal nerve blocks. Analgesia was achieved in all patients to some degree, but the effectiveness of the technique was limited by the currently available local anaesthestics.

Gas-powered jet injection compared with conventional methods of injection using lignocaine and technetium-99m

Plasma concentrations of lignocaine and the clearance rates of technetium-99m were compared in 10 healthy volunteers after injection with a gas-powered jet system and a needle and syringe. The dosage was highly accurate with jet injection. Bioavailability was comparable for both methods.