Precision of Low-Dose Insulin Administration Using the Jet Injector 
Neufeld, N. (1997). Unpublished clinical study.  

Precision and repeatability of insulin dosages using a jet-injector versus conventional syringe was compared. Twenty-eight participants including parents of diabetic children, children with diabetes older than 10 yr. and medical office staff took part in this study. They were asked to draw up 1u, 2u, and 3.5u with each device; the contents were then weighed with a Mettler Analytic Balance. At 1u the sample variance for the syringe was 71.7%, variance for the jet was 7.9%. At 2u, syringe variance was 67.7% and 6.7% for the jet. At 3.5u, syringe variance was 52.1% and 18.1% for the jet. These findings suggest that the jet injector is a useful tool for ensuring accuracy of small dosages of insulin, particularly when considering multiple caregivers may be preparing injections for a given individual. 
 
Survey of Patient Preference for Insulin Jet Injectors Versus Needle and Syringe
Denne, J.R., Andrews, K.L., Lees, D.V., & Mook, W. (1992) The Diabetes Educator vol.18, 22~227.  

Many studies have tested the insulin absorption rate and mechanical reliability of jet injectors. However, no published papers have dealt exclusively with patient preference for this method of administering insulin over a period of years. This paper reports the results of a survey done to determine if use of a jet injector for delivering insulin has an effect on acceptance of and adherence to a regimen of multiple doses of insulin. Over the past 15 years, the authors have instructed approximately 70 patients to use various jet injectors. A questionnaire was developed and sent to 75 patients. Of these, 42 completed and returned the questionnaire. Survey results indicate that even though some problems with the injectors were identified, 70% of those responding still preferred to take insulin by jet injector. 

Plasma Free Insulin Profiles After Administration of Insulin by Jet and Syringe 
Taylor, R., Home, P.D., & Alberti, K.G. (1981). Diabetes Care vol.4, 377-379.  

Plasma free insulin profiles in insulin-dependent diabetic subjects were compared after jet and syringe injection of insulin. Jet injection of insulin resulted in a shift of the free insulin profile to the left. Thus higher plasma free insulin levels were found over the first 30-min after injection (P <0.05), while after 240 min plasma free insulin levels were lower than those seen following syringe injection (P < 0.05). Significant differences in the response of blood glucose and 3 - hydroxyburyrate levels reflected the differences in plasma free insulin levels. Jet administration results in more rapid absorption of insulin and could be useful in providing a more physiological postprandial insulin profile than that seen after conventional injection.  

Comparison of Insulin Levels after Injection by Jet and Disposable Syringe
Malone, J.I., Lowift, S., Grove, N.P., & Shah, S.C. (1986) Diabetes care vol.9, 637~640. 

Intermediate-acting biosynthetic human (NPH) insulin was administered by disposable insulin syringe into the right upper thigh of nine insulin-dependent diabetic youths. Seven days later, the same amount and type of NPH insulin was given in the same anatomic site with a Medi-Jector II, which delivers insulin as a jet stream. Blood was collected before insulin injection and at hourly intervals subsequently for the measurement of glucose and insulin. The total serum insulin mea-sured before the first morning dose with the needle and syringe and the Medi-Jector II was 41.2 + 10.7 uU/ml and 46.2 + 10.7 uU/ml, respectively. During the next 9 h, the areas under the respec-tive total insulin curves were not different, but the area under the free-insulin curve after jet injec-tion was greater than the free insulin area after needle injection (P <.01). The ratio of free/total serum insulin was 0.31+0.02 after needle injection and 0.40+0.03 after jet injection (P <.0025). The peak of total insulin concentration occurred 4.2 h after jet injection of NPH: I h earlier than the peak after needle injection. The plasma glucose at time zero was 197 + 15 mg/ dl before needle injection and 242 + 19 mg/ dl before jet injection. Although diet consumed by each subject on the 2nd study day was identical to that of the 1st day, the mean glucose increase was greater after needle-injected insulin than after jet-spray injection. This indicates that the greater amount of free insulin observed after jet-injected insulin had a direct effect in lowering the plasma glucose. Jet injection may reduce insulin requirements by increasing the availability of free insulin. 

Human Insulin-Induced Lipoatrophy - Successful Treatment Using a Jet-Injection 
Logwin, S., Conget, I., Jansa, M., Vidal, M., Nicolau, C., & Gomis, R. (1996). Diabetes Care vol.19, 255-256.  

Objective- To evaluate the efficacy of the administration of insulin by a jet-injector device in stop-ping and reversing severe human insulin-induced lipoatrophy.  

Case- We report a case of a woman with severe human insulin-induced lipoatrophy who has been treated exclusively with recombinant DNA human insulin since the onset of IDDM.  

Results- The loss of subcutaneous tissue in the injection areas was demonstrated and measured by high-frequency ultrasound. Dermatologic exam demonstrated a severe reduction of fat tissue. After 8 months of administration of human insulin by a jet injector, there were no more new lesions of lipoatrophy and those affected areas were substantially ameliorated.  

Conclusions- Jet-injection devices might constitute a helpful method to treat those patients affected by severe human insulin-induced lipoatrophy. 

Jet-Injected Insulin is Associated with Decreased Antibody Production and Postprandial Glucose Variability Compared with Needle-Injected Insulin in Gestational Diabetic Women
Jovanovic-Peterson, L., Sparks, S., Palmer, J.P., and Peterson, C.M. (1993) Diabetes Care. Vol.16, 1479-1484.  

The study group consisted of 20 women with gestational diabetes mellitus who required insulin randomized to receive either jet-injected or needle-injected human NPH and regular insulin. Variables of interest were evaluated at the start of therapy, weekly until delivery, and 6-wk postpartum that included: 1) insulin antibodies in the mother and her infant, 2) HbAlc, 3) insulin dose, 4) fasting and postprandial glucose levels, and 5) subject acceptance and preference. Results-- Of the 10 women in the needle group, 6 developed significant insulin antibodies compared with 1 of 10 in the jet group. HbAlc and insulin doses were the same in both groups. During the test meal, glucose levels in the jet group were significantly lower, yet none of the women in the jet group experienced blood glucose below 70 mg/dl at 3-4 hr after the meal, compared with 5 in the needle group. Jet injection was associated with a diminished antibody response and postprandial variability compared with needle-injected insulin. Thus, this warrants consideration as a therapeutic option for women with gestational diabetes mellitus and may also be applicable to non pregnant, insulin-requiring diabetic patients. 

Twice-Daily Mixed Regular and NPH Insulin Injections with New Jet Injector Versus Conventional Syringes: Pharmacokinetics of Insulin Absorption 
Halle, J.P., Lambert, J., Lindmayer, I., Menassa, K., Coutu, F., Moghrabi, A., Legendre, L., Legault, C., & Lalumiere, G. (1986) Diabetes Care. vol. 9, 279-282.  

The purpose of the present study was to evaluate the feasibility of using a jet injector in a split and mixed regular and NPH insulin regimen and to compare serum glucose and free-insulin profiles obtained with the injector and the conventional syringe and needle. Twelve insulin-dependent diabetic patients were hospitalized for 5 days. After a stabilization day, six patients received their insulin injection with the injector for 2 days and with the syringe and needle for the following 2 days; the regimen was reversed for the other six patients. Diet, exercise, and insulin dosage remained constant. The serum glucose levels with the injector were consistently lower than those obtained with the syringe at all times of the day except at 5:00 a.m. and 7:30 a.m., when mean values were similar for both treatment. Free-insulin levels were higher with the injector from 10:30 a.m. to 4:30 p.m. These findings suggest that insulin absorption is faster and possibly greater with the injector than with the syringe. When switching from a syringe to an injector insulin program, insulin dose adjustment may be necessary. 

Comparison of Plasma Insulin Profiles After Subcutaneous Administration of Insulin by Jet Spray and Conventional Needle Injection in Patients With Insulin Dependent Diabetes Mellitus 
Pehling, G.B., & Gerich, I.E. (1984) Mayo Clin Proc vol. 59, 751-754.  

The characteristics of plasma free insulin profiles after conventional subcutaneous injection of regular insulin (10 units) and after jet injection of this amount of insulin were compared in eight subjects with insulin-dependent diabetes mellitus. Although administration of insulin with the jet injector resulted in peak plasma free insulin concentrations (45 + 4 uU/ ml) similar to those achieved after conventional injection (47+5 uU.ml), it produced more rapid increases in plasma free insulin concentrations (time to peak concentration, 76 + 11 minutes versus 152 + 16 minutes: P <0.01) and less prolonged hyperinsulinemia. Variability in the peak insulin concentrations and the time to peak concentration was comparable for both methods of administration of insulin. Thus, insulin administered by jet injector may improve control of postprandial hyperglycemia and diminish the risk for late hypoglycemia in some patients with insulin-requiring diabetes mellitus treated with conventional injections of insulin. 

Development of New Jet Injector for Insulin Therapy
Lindmayer, I., Menassa, K., Lambert, I., Moghrabi, A., Legendre, L., Legault, C., Letendre, M., & Halle, J.P. (1986) Diabetes Care vol.9, 29~297.  

To improve diabetic patients' compliance to multiple injection protocols, we developed and tested a new insulin jet injector, the Preci-Jet 50.* The prototype has the following features: small size (14 X 2 cm) and weight (160g), capability of mixing two types of insulin, accuracy and reliability of the ejected volume (dose), ease of use and sterilization, simplicity of design, and capacity of adjusting jet pressure to individual skin resistance. The ejected volume, evaluated by gravimetry, was more accurate and more reliable with the injectors (N = 18), than with 0.5 cc disposable plastic syringes (N = 18). The dead space of injectors (N = 16), as evaluated by isotopic recuperation of radioactive insulin, was minimal, allowing mixed insulin injections. The human-device interface evaluation demonstrated that diabetic patients (N=13) learned easily to manipulate the injector and that their ability to use it properly improved after 1 mo. of use. We conclude that this injector may be a practical tool for insulin dependent diabetic patients.  

* Preci-Jet 50 was a forerunner of the AdvantaJet & the GentleJet.