Applicability of Ionic Liquids in Topical Drug Delivery Systems: A Mini Review

Abstract

The Pharmaceutical Industry has several challenges to overcome, such as poor drug solubility, skin permeation, problems related with the stability of the prepared delivery systems, as well as the type of administration to be used. When choosing the most suitable route of administration, non-invasive routes of administration are preferably chosen, with the oral administration being one of the most used. However, the delivery of drugs through the skin can be an alternative route of administration that avoids the gastrointestinal tract, and overcomes complications associated with the parenteral route since it is a non-invasive technique and is widely accepted among patients. Nonetheless, when formulating these delivery systems other problems need to be addressed, such as the low solubility of many drugs and the reduced stability of some of the developed systems. Thus, finding functional excipients that help to overcome these problems is fundamental. In this context, the valuable properties of ionic liquids will be reviewed herein, particularly with respect to their application in the pharmaceutical field and in topical delivery. Furthermore, some studies, that show the value of ionic liquids as drug solubility/loading, permeation enhancers in topical drug delivery systems, will be summarized.