Objectives The aim of this paper is to describe the essential characteristics and features of microneedles as modern transdermal drug delivery system. Applications of liquid or semisolid pharmaceutical formulation by microneedles improve the outcome of the treatment compared to conventional methods (im. sc.) significantly. biopharmaceutical peculiarities of inhaled medicinal products and contribute to the understanding of guidelines for preparation of documentation for marketing authorization laid down by the European Medicines Agency (EMA), which are related to drug development, production, quality control and stability testing. Materials and Methods Research of this work is theoretical and detailed search of available literature was done by topic and subject of research, authors and journals from general to specialized articles and guidelines relevant to the issues of this paper. The following bibliographic databases and services were researched: PubMed, ScienceDirect and ResearchGate and databases available on the website of the FDA, EMA and ICH. Results For thousands of years the preparations are applied to the skin because the skin is an ideal place for local and systemic drug administration. Although TDD is a non-invasive drug delivery method and provides certain advantages over oral and parenteral administration, skin is an impressive barrier to penetrate most of the drugs. For many years scientist are developing strategies and various transdermal delivery systems in order to overcome the skin barrier and to facilitate rapid and effective leakage of the broader range of molecules. MN presents an advanced and effective TDD system that, besides painless applications, also has various other advantages over other methods of drug administration. The most important advantages are avoiding degradation of the drug in the gastrointestinal system, bypassing the first passage through the liver, improved bioavailability, lower doses of the drug and good tolerability without erythema or edema. The disadvantages of TDD by MN are lower dosage precision compared to subcutaneous administration, as well as MN penetration variability depending on the individual differences in the thickness of SC and other skin layers. Also, the skin provides resistance to penetration of the MN into the skin. MN can be divided into solid, hollow and hydrogel-forming MN, which is a relatively new species of MN. Each type of MN has certain characteristics, advantages and disadvantages. Although there is a market for mass production of MN, regulatory standards and clear quality standards are not defined since the actual MN is still not commercially available. Conclusion Microneedles can be successfully used for the targeted delivery of small molecules, macromolecules, vaccines and nucleic acids into specific tissues, and for the use of drug products that pass by passive diffusion through the SC. Due to the numerous advantages of microneedles, increasing interest of microneedle technology is registered which results with rapidly growing number of scientific papers and patent publications, so application of microneedles has been extended to both, ocular and targeted delivery of drug products. The market for successful mass production of microneedles exists, but mass production has not yet been fully explored due to the difficulty of transferring production from laboratory to commercial batches, and because of the lack of accepted regulatory standards or clearly defined quality standards. EMA has published a new concept document on the development of guidelines on the quality requirements of medicines containing a medicinal product for the delivery or use of the medicinal product „EMA/CHMP/QWP/BWP/661488/2016 Concept paper on developing a guideline on Quality requirements of medicinal products containing a device component for delivery or use of the medicinal product“. Microneedles can penetrate through the outermost layers of the skin indicating a different mechanism of action compared to conventional transdermal patches that apply only to the skin surface and from a regulatory perspective, it can be concluded that the MN will be defined as a new dosage form.