Separable arrowhead microneedles

Abstract

Hypodermic needles cause pain and bleeding, produce biohazardous sharp waste and require trained personnel. To address these issues, we introduce separable arrowhead microneedles that rapidly and painlessly deliver drugs and vaccines to the skin. These needles are featured by micron-size sharp tips mounted on blunt shafts. Upon insertion in the skin, the sharp-tipped polymer arrowheads encapsulating drug separate from their metal shafts and remain embedded in the skin for subsequent dissolution and drug release. The blunt metal shafts can then be discarded. Due to rapid separation of the arrowhead tips from the shafts within seconds, administration using arrowhead microneedles can be carried out rapidly, while drug release kinetics can be independently controlled based on separable arrowhead formulation. Thus, drug and vaccine delivery using arrowhead microneedles are designed to offer a quick, convenient, safe and potentially self-administered method of drug delivery as an alternative to hypodermic needles.

Microneedle characterisation: the need for universal acceptance criteria and GMP specifications when moving towards commercialisation

“…Typically the MN-treated skin is excised from the bulk skin sample, fixed in a suitable media, then instantly frozen using liquid nitrogen and stored at -80°C until the time of analysis. A cryostat is used to slice the sample into cryosections of approximately 6-12 µm thick, which are then typically stained with hematoxylin and eosin stains to observe the MN-created microchannels [47,48,49,65]. An example of results obtained with this procedure is presented in Figure 8.…”

Inkjet printing of transdermal microneedles for the delivery of anticancer agents

“…Fig. 8 shows the application of methylene blue coated metal MNs on porcine skin and the creation of perforations immediately after the MN piercing (Chu and Prausnitz, 2011;Donnelly et al, 2008;Gill and Prausnitz, 2007). The staining disappears after six hours without any marks on the skin indicating successful delivery of the coating material as methylene blue diffuses in the tissue.…”

Toward Biofunctional Microneedles for Stimulus Responsive Drug Delivery

“…Polyvinyl alcohol (PVA)/PVP arrowheads and PVA/sucrose arrowheads were produced, inserted and remained in the skin. 58 Lee et al created dissolving microneedles from CMC and amylopectin. The shafts of the microneedles were loaded with sulforhodamine, which dissolved within 5 minutes, giving a bolus delivery of 0.04ug.…”