Potential for cross-contamination from use of a needleless injector

A Novel Intermediate Attachment to Reduce Contamination in Reusable Core Needle Biopsy Devices

One barrier to breast cancer diagnosis in low-resource settings is that devices for core needle biopsy (CNB) are either disposable and expensive, or reusable and susceptible to internal contamination. Through interviews with field workers and verification experiments, we identified that a common, commercially available, reusable CNB device allows contaminants to enter the driver chamber during firing, necessitating laborious cleaning of the entire device after every use. We introduce a novel CNB device attachment that eliminates this contamination mode and interfaces with existing commercial reusable drivers and low-cost disposable needles. This attachment repositions the driver–needle connection to the exterior of the driver, preventing retrograde flow of blood. Using an unmodified commercial CNB, we replicate chamber contamination by firing into a body fluid-mimicking glycerol solution. Prototypes were tested for their performance in eliminating this contamination. We tested the effectiveness of a cleaning procedure to reduce trace contamination by using a fluorescent dye and measuring the intensity of fluorescence after cleaning. The device's ability to reliably and consistently biopsy tissue with the novel attachment was evaluated using breast tissue models. In these tests, a reusable CNB with our attachment exhibited no measurable internal contamination, and maintained full biopsy functionality as measured by tissue sample weight and length. Minimizing internal device contamination would simplify the cleaning process for reusable biopsy devices. This would improve the accessibility of breast cancer biopsies in low- and middle-income countries (LMICs).

A test method to assess the contribution of fluid shear stress to the cleaning of reusable device surfaces

Adequate cleaning of reusable medical devices is critical for preventing cross-infection among patients. For reusable medical devices, cleaning using mechanical brushes and detergent may not be sufficient to completely remove the infectious contaminants from the surfaces. This study evaluates the role of fluid flow-induced shear stress in the detachment and removal of contaminants from device surfaces. A stainless-steel test coupon, acting as a surrogate for a device surface, was coated with artificial clot of varying mass. The test coupon was exposed to fluid shear stress both with and without an enzymatic detergent. The relationship between clot removal quantity and the applied shear stress was obtained for multiple clot masses. Our results showed that fluid shear increased the effectiveness of the cleaning process. In the absence of flow, soaking the clot surface in the enzymatic detergent removed 67%, 77%, and 95% of the clot for 16 mg, 6.8 mg, and 1 mg initial masses, respectively. In the presence of fluid shear (0.3 Pa for 5 min), approximately 85%, 97%, and 99% of the clot was removed from the surface. The clot mass removed followed a linear relationship (R² = 0.98) versus the applied fluid shear stress. This study showed that different cleaning processes such as fluid shear and detergent action contribute to the soil removal process. This method could be used to evaluate cleaning protocols for minimizing contaminant residue after the reprocessing of medical devices. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1132-1140, 2019.

Current trends in needle-free jet injection: an update

Background

Jet injection can be defined as a needle-free drug delivery method in which a high-speed stream of fluid impacts the skin and delivers a drug. Despite 75 years of existence, it never reached its full potential as a strategic tool to deliver medications through the skin.

Objective

The aim of this review was to evaluate and summarize the evolution of jet injection intradermal drug delivery method including technological advancements and new indications for use.

Methods

A review of the literature was performed with no limits placed on publication date.

Results

Needleless injectors not only reduce pain during drug delivery but also confine the drug more evenly in the dermis. Understanding skin properties of the injection site is a key factor to obtain optimal results as well as setting the right parameters of the jet injector. Until the advent of disposable jet injectors/cartridges, autoclaving of the injector remains the only reliable method to eliminate the risk of infection. Needle-free intradermal injection using corticosteroids and/or local anesthetics is well documented with promising indications being developed.

Limitations

Limitations of the review include low-quality evidence, small sample sizes, varying treatment parameters, and publication bias.

Conclusion

New developments may help reconsider the use of jet injection technology. Future studies should focus on measurable optimized parameters to insure a safe and effective outcome.

Treatment of nail psoriasis with intralesional triamcinolone acetonide using a needle-free jet injector: a prospective trial

BACKGROUND

Treating nail psoriasis is challenging. Corticosteroid matrix injection with needle is a conventional treatment but pain is often a limitation.

OBJECTIVE

Evaluate efficacy and safety of triamcinolone acetonide needle-free injection with the Med-Jet MBX in psoriatic fingernail.

METHODS

Seventeen patients were enrolled between January 2012 and January 2013. Four treatments sessions were scheduled every 4 ± 1 weeks. Clinical efficacy was evaluated according to Nail Psoriasis Severity Index (NAPSI) score of target nail differences before and after the treatment.

RESULTS

Mean baseline NAPSI score was 6.5 on an 8-point scale (95% confidence interval [CI] 5.652-7.348) and mean final NAPSI score was 2.8 on an 8-point scale (95% CI 1.859-3.741), demonstrating statistically significant treatment efficacy (p = .0007). NAPSI score for target nail from baseline to end of treatment was decreased by 46.25%.

CONCLUSION

Treatment with triamcinolone acetonide delivered by Med-Jet MBX is a safe, minimally painful and effective treatment for nail psoriasis.

Needle-free liquid jet injections: mechanisms and applications

Liquid jet injections employ a high-speed jet to puncture the skin and deliver drugs without the use of a needle. They have been used to deliver a number of macromolecules including vaccines and insulin, as well as small molecules, such as anesthetics and antibiotics. This article reviews liquid jet injectors with respect to their historical perspective, clinical applications, mechanisms and future prospects. An overview of the use of jet injectors for delivery of vaccines, insulin and growth hormones is presented. Particular attention is paid to the mechanistic understanding of jet injections, especially the dependence of jet penetration on parameters such as nozzle diameter, velocity and jet power. Finally, gaps in the current understanding are presented and suggestions for future research and development are made.

Current status and future prospects of needle-free liquid jet injectors

Needle-free liquid jet injectors have been used for more than 50 years for parenteral delivery of vaccines and drugs. Although excellent bioavailability has been reported for a number of drugs, occasional pain and bruising have limited wide acceptance of jet injectors. This article reviews jet injectors with respect to their current clinical applications, emerging applications, mechanistic understanding and future prospects.

Jet injector compared with oral midazolam for preoperative sedation in children

BACKGROUND

This study compared onset of sedation and satisfaction with two needleless jet injectors with the oral route for the administration of midazolam.

METHODS

Forty-five children ages 1-6 years were randomly assigned to receive either 0.5 mg kg(-1) oral midazolam, 0.2 mg kg(-1) subcutaneous midazolam by J-Tip injector or 0.2 mg kg(-1) intramuscular midazolam by Bioject injector. After midazolam administration the children were monitored for oxygen saturation, heart rate and level of sedation (0, alert; 1, calm; 2, drowsy; 3, dozing; 4, asleep) every 2 min for 20 min by a physician blinded to the route of administration. Patient satisfaction, resistance to treatment, success of delivery, problems with separation, and acceptance of mask at the time of induction were evaluated after midazolam treatment.

RESULTS

The Bioject showed a faster onset of sedation than either the J-Tip injector or the oral midazolam (P < 0.05). The children were significantly less satisfied with the Bioject and J-Tip administration vs oral midazolam (P < 0.05). There were no differences in resistance, success of delivery, problems with separation, mask acceptance, arterial oxygen saturation or heart rate.

CONCLUSION

Despite children being less satisfied with Bioject injection of midazolam, the procedure is safe, effective and provides a more rapid onset of preoperative sedation in children than either the J-Tip injection or oral route.

'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.