Editing Transdermal patch (section)

==== Soluble or dissolvable MNPs ====
One of the types of MNPs are water-soluble needles made out of soluble polymers or saccharide. However, dissolvable needles cannot efficiently deliver drugs to the dermal layer. Drug maximum concentration cannot be carried out to the skin, as the needles will dissolve beforehand. Fortunately, researchers have developed a water-insoluble backing layer, making the needle last longer in the human body environment. This design enables efficient delivery of more than 90% of the drug within 5 minutes of application of MNPs to the skin.<ref name="Li 2103359">{{Cite journal|last1=Li|first1=Song|last2=Xia|first2=Dengning|last3=Prausnitz|first3=Mark R.|date=2021-06-21|title=Efficient Drug Delivery into Skin Using a Biphasic Dissolvable Microneedle Patch with Water-Insoluble Backing|journal=Advanced Functional Materials|volume=31|issue=44|page=2103359|doi=10.1002/adfm.202103359|pmid=34744551 |pmc=8570388 |issn=1616-301X}}</ref>