TECHNOLOGY OF NANOCAPSULES FOR DRUG DELIVERY

Encapsulation of active ingredients in solid capsules made of biodegradable materials has attracted considerable attention over the past decades. In this brief review, we focus on the preparation of micro- and nanosized capsules and emulsions based on artificial peptides as a fully degradable material. It discusses various approaches to the preparation of polymer-based capsules as well as their critical properties such as size and stability. Dispersed polymer nanocapsules can serve as nanosized drug carriers to achieve controlled release as well as effective drug administration. The stability of the dispersion is determined by the type of surfactant and the nature of the outer shell of the capsule. Their release and degradation properties largely depend on the composition and structure of the capsule walls. Another important criterion is the capsule size, where the optimum is usually observed in the radius range of 100 to 500 nm. Nanocapsules can be prepared in fundamentally different ways: nanoprecipitation, emulsion diffusion, double emulsification, emulsion coacervation, polymer coating and layer-by-layer, and depend on the methodological and mechanistic aspects, encapsulation of the active substance and the raw materials used. Nanocapsules made using various biodegradable polymers are attracting increasing attention and are considered as one of the most promising drug delivery systems. Nanoencapsulated systems have a relatively higher intracellular absorption compared to microparticles, which can be modified depending on the surface charges of the nanocapsules and the hydrophilic or hydrophobic nature of the polymer used to form the shell.