Microneedles as Modern Carriers of Plant Extracts

Recently, intensive research has been conducted on effective and simple systems for delivering active substances deep into the epidermis, e.g., for the treatment of skin inflammation. One possibility can be the use of soluble microneedles in which active compounds are encapsulated. This article describes the preparation of modern carriers, namely microneedles with encapsulated extracts of red beet or parsley leaves, that are rich in active substances with antioxidant and anti-inflammatory properties, specifically betanin and apigenin. The concentration of hyaluronic acid sodium salt, the method of preparing the solution, and the technique of the complete filling of molds were optimized. Plant extracts were obtained with sonication or maceration. In order to characterize the extracts obtained, several techniques were employed, such as UV-Vis, LC-MS, GC-MS, and FTIR-ATR. The analyses performed allowed for confirmation of the presence of selected active substances in the extracts. The most optimal solution of the microneedles' precursor turned out to be the one with a concentration of 10 wt.% of sodium hyaluronate, prepared by stirring and sonication. The most efficient extraction method for each plant was chosen, and the extracts were introduced into a solution of hyaluronic acid sodium salt. The resulting soluble microneedle patches can be used as an alternative to the traditional methods of delivering anti-inflammatory and antioxidant substances of plant origin.