Assessing the integrity and mechanical properties of commercial microneedles: innovation or fad?

With the rapid advancements in microneedle technology, the translation of microneedles to end users is now achievable. However, concerns about microneedle product quality persist due to the absence of standard guidelines. This study aims to evaluate the integrity, mechanical properties and skin penetration performance of commercially available polymeric-based cosmetic microneedle patches. The patches were characterised for needle geometry/dimension, mechanical strength and insertion capabilities using in vitro Parafilm^® M and ex vivo porcine skin models. Ten microneedle patches investigated have needle height of ~ 180-500 μm, base width of ~ 100-270 μm and interneedle spacing of ~ 320-686 μm with fracture force up to 14 N. Some microneedles showed deformed needles due to poor packaging protection. Despite most microneedle patches showed good insertion into Parafilm^® M, only 7 patches demonstrated ex vivo porcine skin insertion in OCT analysis. Nevertheless, only 1 microneedle patch demonstrated full skin insertion ratio due to a lower needle density. This study highlights the critical role of needle geometry, mechanical properties and packaging in ensuring microneedle functionality. More importantly, microneedle products are a significant 'innovation' that must prioritise puncture performance and packaging to ensure effectiveness and avoid being dismissed as a mere 'fad'.