Development of new jet injector for insulin therapy.

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 (160 g), 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 the 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.

Twice-daily mixed regular and NPH insulin injections with new jet injector versus conventional syringes: pharmacokinetics of insulin absorption.

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 treatments. 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.