Topical Emulgel: Basic Considerations in Development and Advanced Research

Abstract

Emulgel is a promising drug delivery strategy that has gained popularity in recent years for topical delivery of hydrophobic drugs. Emulgel is an emulsion that is gelled by mixing it with gelling agents. It is an interesting topical drug delivery system as it has a dual release control system, i.e., gel and emulsion. Emulgel has several favorable properties for dermatological use such as being thixotropic, greaseless, easily spreadable, easily removable, emollient, nonstaining, long shelf life, transparent and pleasing appearance. Despite, many advantages of the emulgel, the disadvantages include low permeability, poor pharmacokinetics and pharmacodynamics performance; therefore an advanced concept nanoemulgel came into the existence. Regardless of having few limitations, nanoemulgel formulation can be considered as impending and promising candidates for topical delivery of lipophilic drugs in the future. To know the potential of emulgel as a delivery vehicle, the present review offers a comprehensive overview on the rationale behind the use of emulgel, formulation considerations and characterization of emulgel and advanced research in the emulgel. Furthermore, we have summarized and discussed the outcome of different in vitro and in vivo studies of emulgel or nanoemulgel. Finally, the major challenges of nanoemulgel drug delivery system, patented and marketed emulgel or nanoemulgel formulations have been discussed. Based on the studies covered in this manuscript, it was understood that emulgel or nanoemulgel has emerged as an optimistic approach in the topical delivery of hydrophobic drugs to improve solubility, permeability and bioavailability, and reduce toxicities.