Are needle-free injections a useful alternative for growth hormone therapy in children? Safety and pharmacokinetics of growth hormone delivered by a new needle-free injection device compared to a fine gauge needle

The clinical safety, use and pharmacokinetics of a new needle-free device for delivery of growth hormone (GH) were compared with those of conventional needle injection devices. In an open-label, randomized, 4-period crossover study, 18 healthy adults received single subcutaneous injections of Genotropin administered by the Genotropin ZipTip needle-free device and by conventional injection. Bioequivalence was established between the devices. In a separate open-label, randomized, multicenter, 2-period crossover study, pediatric patients underwent 2-weeks Genotropin treatment administered by the Genotropin ZipTip and by a fine-gauge needle device (>95% used the Genotropin Pen). In total, 128/133 patients who were treated completed the study. Genotropin ZipTip was well tolerated and >50% of patients found no difference between the devices for all parameters assessed. After study completion, >20% patients preferred to continue using Genotropin ZipTip. Although statistical analyses demonstrated superiority of the Genotropin Pen versus Genotropin ZipTip for bleeding, pain, soreness, and bruising, Genotropin ZipTip was considered to provide a safe and bioequivalent alternative to needle injection.

Transdermal drug delivery by jet injectors: energetics of jet formation and penetration

PURPOSE

Pressure-driven jets have been used for intradermal delivery of a variety of drugs. Despite their introduction into clinical medicine, variability and occasional bruising have limited their widespread acceptance. Although numerous clinical studies of jet injectors have been reported in the literature, surprisingly little is known about the mechanisms of jet penetration into the skin. In this article, we report results of our studies aimed at determining the dependence of drug delivery on jet velocity and diameter. These studies were performed using two experimental models, porcine skin and human skin. Our rationale for using two models was to explore the possibility of using porcine skin as a model for human skin.

METHODS

Dermal penetration of jets possessing a range of diameters from 76 microm to 559 microm and a range of velocities from 80 m/s to 190 m/s was studied into human and porcine skin. Penetration was quantified using radiolabeled mannitol. Pressure and velocity of the jets were measured using a calibrated pressure transducer and high-speed photography.

RESULTS

Penetration of the jet into the skin was determined by two main parameters, jet diameter and average jet velocity. Substantial variation in jet penetration into porcine skin was observed for skin pieces obtained from different anatomic locations. For porcine skin, a parabolic dependence of jet delivery on velocity and diameter was observed. The threshold velocity is suggested to be between 80 and 100 m/s for a jet diameter of 152 microm. Above the threshold velocity, the delivery increased for velocities up to 150 m/s, after which delivery decreased with increasing velocity. At a constant velocity of 150 m/s, jet delivery exhibited a maximum at a diameter of 152 microm. Results obtained with human skin were qualitatively similar but quantitatively different. The threshold velocity for jet penetration into human skin was comparable with that in porcine skin; however, the maxima observed in jet delivery into porcine skin with respect to jet velocity was not apparent for human skin over the range of velocities explored.

CONCLUSIONS

These studies offer a quantitative analysis of jet penetration into the skin.

Pharmacokinetics and pharmacodynamics of a new formulation of recombinant human growth hormone administered by ZomaJet 2 Vision, a new needle-free device, compared to subcutaneous administration using a conventional syringe

The objective of the present study was to investigate the applicability of a new human growth hormone (Zomacton) formulation, administered both by a conventional syringe and by a new needle-free device (ZomaJet 2 Vision). The study was performed according to a randomized, controlled, three-period crossover design. On 3 separate days, all subjects received in a random order a single subcutaneous injection of 1.67 mg hGH as follows: Zomacton 4 mg/ml conventional syringe administration (Treatment A), Zomacton 10 mg/ml conventional syringe administration (Treatment B), or Zomacton 10 mg/ml ZomaJet 2 Vision administration (Treatment C). The pharmacokinetic parameters were assessed for the individual subjects in each group by noncompartmental methods. Bioequivalence was assessed based on log-transformed AUC and C(max) values. To investigate the effectiveness of two formulations and the different administration methods, the pharmacodynamic parameters (insulin-like growth factor-1 [IGF-1] and free fatty acids [FFA]) were also evaluated. No subjects were withdrawn due to adverse events. The local tolerance assessment (assessed by inspection)revealed no differences between ZomaJet2 Vision application and conventional injections by syringe. Administration of the new hGH formulation by syringe was found to be bioequivalent with the reference treatment, both based on AUC and C(max) values; the new formulation administered by use of ZomaJet 2 Vision was found to be bioequivalent based on AUC values only. When using the ZomaJet 2 Vision, the absorption of hGH was faster, resulting in higher C(max) values. The maximum hGH serum concentration of around 20 ng/ml was observed 3.5 to 4 hours after drug administration. The terminal half-life was found to be around 2.5 hours. Comparison of the pharmacodynamic profiles (both IGF-1 and FFA) demonstrated bioequieffectiveness. These results support the use of jet injectors as a viable alternative to the traditional injection pens.

'Needle-free' delivery of local anesthesia: a valuable option in pediatrics

Needleless injection or jet injection of medication has had a rather limited clinical use in children's healthcare beyond mass vaccinations. Medications injected into children with a needle-free system include local anesthetic agents, sedatives (midazolam), and anesthetic induction agents (ketamine). Reports suggest that local discomfort is often negligible and costs are often minimal. Risks associated with this simple and flexible technique are considered to be markedly less than alternative approaches, such as syringe and needle. Further investigations are needed to confirm initial reports and establish current and other uses of jet injectors in children.

Potential use of autoinjector-packaged antidotes for treatment of pediatric nerve agent toxicity

STUDY OBJECTIVE

We sought to determine the feasibility of discharging Mark 1 atropine and pralidoxime autoinjectors into small, sterile vials to facilitate the potential intramuscular injection of these antidotes, particularly pralidoxime, on a milligram per kilogram basis to small children.

METHODS

Autoinjectors were swabbed with isopropyl alcohol and then discharged into emptied, sterile, plastic 10-mL vials. This was repeated with the investigator garbed in standard personal protective gloves and full face mask and hood. The autoinjector injection surfaces were cultured.

RESULTS

The autoinjectors were easily discharged into the vials without need for practice or special dexterity, even when investigators were garbed in protective gear. A small core of rubber stopper might be injected into the vial, and thus, the vial contents need to be withdrawn through a filter needle before reinjection. The autoinjector injection surfaces were sterile after alcohol swabbing.

CONCLUSION

Autoinjectors might be a readily available source of concentrated pralidoxime for potential intramuscular use in small children.

[Theoretical bases of a cardio-synchronised jet injection system into the vena cava]

Aim of this paper is to present a procedure aimed at raising the flow rate in the vena cava. To this purpose some fluid is injected at high speed in the vessel, accelerating the flow and dragging the stagnating flow upstream the catheter. In order to raise the efficiency of the system and to avoid damage to heart valves, the injection is synchronised with the diastole. A prototype of an injection system has been designed and built, in order to reach these goals. The injection times are controlled by the electrocardiogram track of the patient, in such a way that the maximum flow rate occurs when the tricuspid valve is open. A "dragging effect" index, that is the ratio between overall flow rate induced by any injection (injected flux plus dragged flux) and injected flux flow rate has been evaluated, both theoretically and experimentally. An experimental model of the lower vena cava has been built and used to measure the velocity profile in the vessel. The dragging effect at the confluence between the two iliac and the vena cava has been verified. By making the catheter sections smaller and/or raising the feeding pressure it is possible to have the injection of small volumes at high speed, capable of moving the blood in the vena cava with a minor contribution of external fluid, thus reducing risks of volume overload and overdiluition of blood.

Enhancement of fibrinolytics with a laser-induced liquid jet

BACKGROUND AND OBJECTIVE

There are several problems inherent in the treatment of cerebral embolisms, such as the narrow therapeutic time window and the severe side effects of fibrinolytic drugs. There is thus need of a new method of removing a cerebral thrombus more rapidly using smaller amounts of fibrinolytics.

STUDY DESIGN/MATERIALS AND METHODS

The liquid-jet generator was made by insertion of an optical fiber (diameter: 0.6 mm) into a balloon catheter (6 Fr). A pulsed holmium (Ho) YAG laser (pulse duration time = 350 micros) was used as a laser source. The maximum penetration depth of a liquid jet generated with this device into a gelatin artificial thrombus was measured at various stand-off distances (L; distance between the optical fiber end and the catheter exit). Based on the result, a stand-off distance of 13 mm was chosen to investigate the enhancement of urokinase (UK) efficacy by only a single operation of the liquid-jet device in artificial thrombi made of human blood.

RESULTS

Maximum penetration depth increased in proportion to L and reached a maximum value (9 mm) when L was around 13 mm. Fibrinolysis rates (%) after incubation with a small amount of UK for 10 and 30 minutes were predominantly raised by a single use of the laser-induced liquid jet (5.4 +/- 2.4 vs. 22.6 +/- 6.1 and 7.3 +/- 3.8 vs. 38.3 +/- 5.6, respectively (mean +/- SD, P < 0.001)).

CONCLUSIONS

A laser-induced liquid jet effectively promoted fibrinolysis in vitro with use of only a small amount of fibrinolytics.

Model-based estimates of risks of disease transmission and economic costs of seven injection devices in sub-Saharan Africa

OBJECTIVE

To investigate and compare seven types of injection devices for their risks of iatrogenic transmission of bloodborne pathogens and their economic costs in sub-Saharan Africa.

METHODS

Risk assumptions for each device and cost models were constructed to estimate the number of new hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections resulting from patient-to-patient, patient-to-health care worker, and patient-to-community transmission. Costs of device purchase and usage were derived from the literature, while costs of direct medical care and lost productivity from HBV and HIV disease were based on data collected in 1999 in Côte d'Ivoire, Ghana, and Uganda. Multivariate sensitivity analyses using Monte Carlo simulation characterized uncertainties in model parameters. Costs were summed from both the societal and health care system payer's perspectives.

FINDINGS

Resterilizable and disposable needles and syringes had the highest overall costs for device purchase, usage, and iatrogenic disease: median US dollars 26.77 and US dollars 25.29, respectively, per injection from the societal perspective. Disposable-cartridge jet injectors and automatic needle-shielding syringes had the lowest costs, US dollars 0.36 and US dollars 0.80, respectively. Reusable-nozzle jet injectors and auto-disable needle and syringes were intermediate, at US dollars 0.80 and US dollars 0.91, respectively, per injection.

CONCLUSION

Despite their nominal purchase and usage costs, conventional needles and syringes carry a hidden but huge burden of iatrogenic disease. Alternative injection devices for the millions of injections administered annually in sub-Saharan Africa would be of value and should be considered by policy-makers in procurement decisions.

Clinical evaluation of the efficacy of anesthesia and patient preference using the needle-less jet syringe in pediatric dental practice

Most dentists are aware that local anesthetic injections produce the highest incidence of disruptive behavior in children. Both psychological and physiological monitoring of the response of children to dental injection, support empirical observations of clinicians. The needle-free injector delivers local anesthesia without the use of a needle. This is accomplished by delivering the anesthetic solution under high compressive forces. One hundred children between the ages of 3 to 13 years underwent operative procedures using Madajet XL. There was a statistically significant difference in favor of the instrument. The instrument was completely successful in providing anesthesia.

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.

Delivery of low molecular weight heparin for prophylaxis against deep vein thrombosis using a novel, needle-less injection device (J-Tip)

Given daily, low molecular weight (LMW) heparins are established for prophylaxis against deep vein thrombosis (DVT). We describe delivery by a novel, needle-less device that is virtually painless in action. Its use could provide benefits for patients in terms of comfort both psychologically and physically, and for healthcare workers in terms of safety from needle-stick injury. Patients undergoing elective surgery received LMW heparin delivered subcutaneously by either a standard needle and syringe or by the needle-less injection device, J-Tip. Pain was scored at the time of injection and plasma anti-factor Xa levels compared between the two methods of drug delivery 4 h later: 29 patients received LMW heparin delivered by the J-Tip and 31 patients by standard needle and syringe. The J-Tip was significantly more comfortable for the patient as the method of drug delivery (P < 0.001). When delivered by the J-Tip, LMW heparin was equally as efficacious, as plasma anti-factor Xa levels were similar for both methods of delivery (P < 0.42). In summary, delivery of LMW heparin by the J-Tip device was both comfortable and effective. These findings, taken in conjunction with its ease of use and complete freedom from risk of needle-stick injury might encourage further examination and use of this type of product.

Evaluation of a needle-free injection system for local anaesthesia prior to venous cannulation

We evaluated a single-use, disposable, carbon-dioxide-powered, needleless injector (J-Tip, National Medical Products Inc., CA, USA), which is claimed to deliver a virtually painless, subcutaneous injection. Seventy-two patients undergoing various types of surgery had a large-bore intravenous cannula inserted prior to induction of general anaesthesia. Three minutes beforehand, a subcutaneous injection of 0.3 ml of 1% plain lidocaine was administered. Subjects were randomly allocated to receive the lidocaine either by the needleless injector or from a conventional syringe and a 25 G needle. Pain scores were recorded on injection of the lidocaine and on insertion of the cannula. There was significantly less pain on injection with the needleless injector than with the 25 G needle (p < 0.001) but, surprisingly, there was more pain on cannulation (p < 0. 001). We conclude that the device certainly delivers a less painful subcutaneous injection than a 25 G needle, but perhaps provides less effective skin anaesthesia for venous cannulation at sites where the subcutaneous space is small; its use might be better suited to areas where the subcutaneous space is deeper.

Local tolerance, pharmacokinetics, and dynamics of ganirelix (Orgalutran) administration by Medi-Jector compared to conventional needle injections

The feasibility of administering a relatively high dose of the gonadotrophin-releasing hormone (GnRH) antagonist ganirelix by means of a needle-free injection device, which could be useful in the long-term treatment of sex-steroid-dependent disorders, was evaluated in a randomized, crossover study in 16 healthy females. Local tolerance and pharmacokinetics of ganirelix administered by MediJector versus conventional needle injections were compared. Additionally, the pharmacodynamic effect was evaluated. Two milligrams of ganirelix was administered s.c. once daily for 7 days by Medi-Jector or conventional needle in a randomized sequence, without a washout period. No apparent differences in local tolerance were observed. Most injections (87.5%) gave either no or only a mild reaction. Of the moderate reactions, swelling and redness were reported most frequently (overall 4.9 and 8.5% per injection, respectively). Administration by Medi-Jector was bioequivalent to conventional needle injection with respect to the peak concentration and area under the curve. A profound suppression of luteinizing hormone and follicle stimulating hormone was observed. Serum oestradiol and progesterone concentrations were relatively low prior to treatment and remained low during the entire study period. In conclusion, administration of a relatively high dose of ganirelix by Medi-Jector might be useful for long-term treatment of sex-steroid dependent disorders.

The latest developments in insulin injection devices

The next several years promise dramatic changes in the treatment of diabetes, many of which will be driven by rapidly developing technology. Today's patient with diabetes has ready access to more information about the disease and its treatment options. As a result of this increased knowledge base, insulin-treated patients have become more autonomous in the management of their diabetes and may be better prepared to participate in making informed choices regarding insulin delivery devices. As with any insulin regimen, diabetes educators are encouraged to provide ongoing patient education and follow-up to assure optimal use of these new technologies.

Transdermal and transmucosal powdered drug delivery

High-velocity powder injection is a promising new drug-delivery technique that provides needle- and pain-free delivery of traditional drugs, drugs from biotechnology such as proteins, peptides, and oligonucleotides as well as traditional and genetic vaccines. The energy of a transient helium gas jet accelerates fine drug particles of 20 microns-100 microns diameter to high velocities and delivers them into skin or mucosal sites. This review describes the configuration and operating principles of devices that accelerate the particles, the required properties of the particles, the characteristics of the target tissues, and features of the developmental test methods. Preclinical and clinical results that best characterize the technology and introduce its potential as a drug-delivery platform are presented.

[Cost of tetanus toxoid injection using a jet-injector (Imule) in collective immunization in Senegal: comparison with injection using a syringe and resterilizable needle]

Needle-less jet injectors were developed by the US army after World War II. Their principal use, however, has been in the administration of lyophilized vaccines from multidose vials to at-risk populations in developing countries. In 1983, a hepatitis B epidemic occurred among customers of a beauty clinic in California (USA) following the use of jet-injectors, demonstrating a clear risk of cross-contamination associated with this technique. As a result, the WHO and Unicef stopped recommending jet-injectors for collective immunizations in developing countries. To eliminate the risk of contamination, Pasteur Mérieux Sérums et Vaccins (now Aventis Pasteur) developed, in 1990, jet-injectors for use with single-use vaccine cartridges. These injectors were tested for tetanus toxoid, DTP, influenza, hepatitis A and typhoid Vi vaccination. The immunogenic reaction was as strong and the injection as well tolerated as for injections using a standard needle and syringe. The additional cost of the Imule technique was evaluated in a district-wide (127,000 inhabitants) tetanus toxoid immunization program at Velingara, Senegal in 1993. The total cost was estimated to be 1.51 FF (76 F CSA, 0.32 US dollars) for one dose of tetanus vaccine given by needle and syringe and 2.41 FF (121 F CSA, 0.56 US dollars) for one dose given by Imule. Thus, the additional cost of injection by ImuleTM was 0.90 FF (45 F CSA, 0.21 US dollars). The cost of cross infection in sub-Saharan Africa has been estimated to be 2.37 FF (118 F CSA, 0.55 US dollars) per injection if injection practices are not supervised. Therefore, the Imule technique may be considered to be cost-effective. However, the technique is still not completely reliable, as shown by the total breakdown of four jet injectors during this vaccination session. Lyophilized vaccines have also not been tested in the field. Vaccinators prefer Imule, training is easy and immunization can be carried out on a day-to-day basis with no vaccine wastage. Imule is not yet in mass production, which would reduce costs. In the face of the ever-increasing risk of cross-contamination during vaccination sessions in sub-Saharan Africa, the Imule technique deserves considerable attention.

Intradermal DNA immunization by using jet-injectors in mice and monkeys

We have used spring powered jet injectors to deliver a solution of a naked DNA vaccine encoding the influenza hemagglutinin HA into the skin of mice and monkeys. We compared the immune responses induced by this needleless injection technique into the skin to the responses induced by a classical i.m. immunization. Both routes of immunization induced significant ELISA antibody titers and hemagglutination inhibition (HI) titers that were above the usual threshold values predictive of protection against influenza in mice and monkeys. In mice, both ways of immunization were equally efficient in inducing HA-specific CTL responses. Regarding antibody isotypes, the IgG1/IgG2a ratio was in favour of the IgG2a isotype for i.m. immunization and more balanced for i.d. immunization. The ability of the two injection techniques to induce immunity in mice did not correlate with transgene expression in the site of administration. In fact, local gene expression was 10-100 fold more important in the injected muscle as compared to the jet-injected skin when assessed by using the luciferase reporter system.

Fluid mechanics analysis of a spring-loaded jet injector

A syringe jet injector is a device designed to administer a drug quickly and painlessly through the skin. Though syringe jet injectors have been in use for almost 50 years, current designs still suffer from inconsistent performance. To better understand the fluid mechanics of jet injection and gain insight into how the design might influence performance, two theoretical analyses to determine the fluid pressure profile at the exit orifice were conducted. The first was a continuum analysis assuming static incompressibility. Results demonstrated that the maximum jet pressure was highly sensitive to the spring constant, initial piston velocity, and piston cross-sectional area while the time to achieve the maximum pressure was most sensitive to the injection chamber length, initial piston velocity, bulk modulus of the injectant, and the piston cross-sectional area. The second analysis was a shock wave analysis. Results demonstrated a stepwise pressure-time plot that was similar in magnitude to that for the continuum analysis assuming static incompressibility. Results from these two investigations are useful for design modification of the jet injector to achieve desired pressure-time profiles at the orifice. Control of pressure-time profiles may help to achieve a more consistent and effective injection process.

Subcutaneous administration of midazolam: a comparison of the Bioject jet injector with the conventional syringe and needle

PURPOSE

The purpose of this study was to compare jet injection to a syringe and needle in terms of the difference in discomfort and pharmacokinetics after the subcutaneous administration of midazolam.

PATIENTS AND METHODS

Using a prospective, randomized, double-blinded study design, 14 subjects were administered midazolam on two separate occasions (at least 2 weeks apart). The subjects were randomly distributed into two groups: syringe and needle (saline)/jet injector (midazolam) or syringe and needle (midazolam)/jet injector (saline). The subjects were randomly assigned to receive either EMLA (eutectic mixture of local anesthetics) or a placebo at the injection site for the first administration and the other topical agent on the second visit. Each subject received one subcutaneous injection in the deltoid region per arm per day. Each injection contained the same volume of solution. Subjects completed visual analog scale (VAS) questionnaires assessing the discomfort of the injection. Blood samples were taken at specified intervals over 2 hours for determination of midazolam levels.

RESULTS

The discomfort associated with the injection was less with the Biojector 2000 (Bioject Inc, Portland, OR) although this was not statistically significant. However, persistent discomfort was significantly greater at the needle site. The mean peak plasma level of midazolam was achieved more rapidly with the Biojector 2000 than with the syringe and needle (P < .05). However, the peak plasma level after jet injection or injection with a syringe and needle was not statistically different.

CONCLUSION

The results of the study show that the Biojector 2000 is a needle-free injection system that can be used for the administration of a premedicant before induction of anesthesia. It has several advantages, including the potential reduction of anxiety associated with the "fear of needles" and occupational injuries.