Rapid local anesthesia in humans using minimally invasive microneedles

Area of Science:

• Dermatology
• Anesthesiology
• Biomedical Engineering

Background:

• Minimally invasive microneedle technology offers a potential alternative to traditional hypodermic needles for drug delivery.
• Assessing the pain, efficacy, and onset of local anesthesia induced by microneedle-delivered lidocaine is crucial for clinical adoption.

Purpose of the Study:

• To compare the pain, onset, and efficacy of lidocaine injection via microneedles versus standard hypodermic needles.
• To evaluate patient preference and pain perception associated with microneedle injections.

Main Methods:

• A randomized, single-blinded, within-participant controlled study involving 15 human subjects.
• Lidocaine was injected into the forearm and dorsum of the hand using hollow 500-microm microneedles and 26-gauge hypodermic needles.
• Pain was assessed using a visual analog scale (VAS), and numbness area/depth were measured at intervals.

Main Results:

• Microneedle injections resulted in significantly lower VAS pain scores compared to hypodermic needles.
• No significant difference was observed in the area or depth of numbness, indicating comparable efficacy and rapid onset of anesthesia.
• 80% of participants found microneedles not painful, and 77% preferred them over hypodermic needles.

Conclusions:

• Microneedle-based lidocaine delivery is a safe, effective, and less painful alternative to hypodermic injections for local anesthesia.
• This technology demonstrates rapid onset and comparable efficacy to traditional methods, with significant patient preference.