Nanotechnologies for intranasal drug delivery: an update of literature

Scientific research has focused its attention on finding an alternative route to systemic oral and parenteral administration, to overcome their usual drawbacks, such as hepatic first-pass which decreases drug bioavailability after oral administration, off-target effects, low patient compliance and low speed of onset of the pharmacological action in first-aid cases. Innovative drug delivery systems (DDS), mainly based on polymer and lipid biocompatible materials, have given a great prompt in this direction in the last years. The intranasal (IN) route of administration is a valid non-invasive alternative. It is highly suitable for self-administration, the drug quickly reaches the bloodstream, largely avoiding the first pass effect, and can also reach directly the brain bypassing BBB. Association of IN route with DDS can thus become a winning strategy for the controlled delivery of drugs, especially when a very quick effect is desired or needed. This review aims at analyzing the scientific literature regarding IN-DDS and their different ways of administration (systemic, topical, pulmonary, nose-to-brain). In particular, attention was devoted to polymer- and lipid-based micro- and nanocarriers, being the topic of most published articles in the last decade, but the whole plethora of colloidal DDS investigated in recent years for IN administration was presented.