Table 1.
Thedecision matrix for the design of suitable microneedles on the following performances presenting as low efficacy (✖), moderate efficacy (▲), and high efficacy (🞅). Reprinted from ref. [21].
| MicroneedleType | Solid Microneedle | Coated Microneedle | Dissolving Microneedle | Hydrogel Microneedle | |
|---|---|---|---|---|---|
| DecisionParameter | |||||
| Drug dose | 🞅 High | ✖ Low ▲ (If several patches are used) |
✖ Low ▲ (If several patches are used) |
🞅 High | |
| Onset of action (Pharmacokinetics/ pharmacodynamics) | ✖ Slow release by diffusion |
🞅 Rapid dissolution |
🞅 Dependent on the formulation |
✖ Slow release by diffusion |
|
| Delivery period | ▲ Several hours (agents that keep the pores open longer are additionally needed) | ✖ Several minutes |
🞅 Several minutes to weeks (depending on the formulation) |
▲ Several hours | |
| Delivery efficiency (Expensive drugs require high delivery efficiency) | ✖ Some drug remains in the patch or formulation |
🞅 | 🞅 | ✖ Some drug remains in the patch |
|
| Sharp waste generation | 🞅 | 🞅 | ✖ No sharp waste |
▲ Swollen hydrogel microneedle tip | |
| Packaging | ▲ Separate packaging for microneedles and formulation | 🞅 | 🞅 | 🞅 | |
| Patch-wearing time | ✖ Several hours |
🞅 Several minutes |
🞅 Several minutes |
✖ Several hours |
|