Microneedles as Novel Drug Delivery Platforms: Fabrication Techniques, Evaluation Methods, and Clinical Potential

Microneedle-based drug delivery has received considerable attention and is rapidly approaching commercialisation owing to the availability of different scalable techniques to yield various microneedles. Numerous materials such as metals, silicones, polymers, and carbohydrates have been employed to fabricate microneedles. Microneedles offer a range of benefits to patients, not only because of their minimally invasive and comfortable nature, but also because of their availability in various geometries. Microneedles are useful for various applications, such as topical, ocular, and nail delivery of small drug molecules, proteins, peptides, and nucleotides. Various fabrication methods for microneedles have been tested for various compounds. Different evaluation tests have been conducted to demonstrate the applicability of microneedles for the delivery of a variety of materials in a desired manner. Microneedles are used in vaccine administration, drug delivery, and cosmetic applications. However, certain issues such as the selection of suitable substances and fabrication techniques that meet the requirements of drug delivery need to be investigated.