Research & Studies: Pertinent Abstracts

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.  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. 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®.