Hyaluronic acid: A review on its biology, aspects of drug delivery, route of administrations and a special emphasis on its approved marketed products and recent clinical studies

Hyaluronic acid (HA) is a large non-sulphated glycosaminoglycan that is an important component of extracellular matrix (ECM) and a biodegradable polymer. Due to a variation in its molecular weight, HA derivatives can be utilized to make different formulations like fillers, creams, gels and drops. HA based drug research has seen a recent surge largely due to some properties like mucoadhesion, biocompatibility and ease of chemical modification. Such properties of HA have led to applications in tissue regeneration, anti-aging and anti-inflammatory medications. HA can be conjugated, functional izecl or used as a nanocarrier supplement with a definite increase in its cellular uptake and efficiency. HA when encapsulated in a nanocarrier may help to improve the ECM growth and provide a sustained release of agents. This review discusses the mechanistic behavior of HA pertaining to its biological synthesis and degradation. It also discusses the administration of some noteworthy and recent HA based formulations through different routes for application in various physiological conditions along with their ongoing clinical trial updates and approved marketed products. (C) 2019 Elsevier B.V. All rights reserved.