The Effects of System Parameters on In Vivo Injection Performance of a Needle-Free Injector in Human Volunteers

Abstract

Both device-related factors and subject variables interact to mediate in vivo performance of a needle-free injector.

Needle‐Free Subcutaneous Sumatriptan (Sumavel™ DosePro™): Bioequivalence and Ease of Use

“…For Sumavel™ DosePro™, when observed closely it is immediate. This is because the injection takes place during a 10th of a second, and the s.c. 0.5 mL bolus of fluid then requires time to dissipate in the potential space of the s.c. tissues; the undissipated bolus causes the immediate swelling 11 . The frequency of swelling reports then continuously falls at succeeding time points.…”

“…On an intent‐to‐treat basis (ie, without removal of these 4 subjects from the database), this was sufficient to reduce mean exposure and to violate the prospective criteria for bioequivalence. Prior experience suggests that relative lack of adipose tissue at the site of administration provides insufficient space for the injectate, and that this is more important for rapid administrations in comparison with slower ones 11 . When approved by regulatory authorities, the use of Sumavel™ DosePro™ at the arm will not be recommended, and patients will be encouraged to use the thigh or the abdomen.…”

“…There had previously been smaller‐scale pilot studies of prototype delivery systems. These included studies of systems parameters on administration performance in normal volunteers, 11 and a study of priming mechanism manipulation, again in normal volunteers, and not in patients actually experiencing migraine attacks (unpublished). Both studies were conducted according to the principles of the Declaration of Helsinki, Good Clinical Practices guidelines, and Part 21 Code of Federal Regulations ( CFR ) as it applies to investigational new drugs (section 312) and human protections (sections 50 and 56).…”

“…The resulting jet of medication (about 380 microns diameter) is propelled through the skin and into the s.c. tissue, delivering 0.5 mL in less than 100 milliseconds. There is never any contact between the medication and the nitrogen gas, and the latter exhausts from the side of the delivery system 11 …”

Needle-Free Jet Injection of Rapid-Acting Insulin Improves Early Postprandial Glucose Control in Patients With Diabetes

“…Importantly, the current device has a built-in lock-release system that only releases insulin when proper skin contact has been made and sufficient pressure has been applied to the nozzle of the injector. Other factors that determine optimal insulin delivery relate to jet velocity and nozzle diameter (22–24). Our data are therefore in part specific to the jet injector used and cannot be extrapolated to other jet injectors.…”