Bigels: A unique class of materials for drug delivery applications

Bigels, combination of organogel and hydrogel, are unique solid-like formulations with improved properties for food, cosmetics, and pharmaceutical applications. Bigel possesses merits of both phases, aqueous and oily, and displays better properties than either of the single gel. The uniqueness of bigels comes from their ability to deliver both hydrophilic and lipophilic active agents, enrichment of hydration of stratum corneum, easily spreadable, and so on. The main objective of this review article is to provide a thorough insight into the classification of bigels on the basis of synthesis method and morphology and also to demonstrate the detailed analysis of bigel formulations by considering different characterization techniques. Moreover, a special focus is given on the applications of bigels as drug delivery vehicles by transdermal route.