Advances in rheological study of topical preparations for skin

Topical preparations for skin, including the commonly used dosage forms of ointments, creams, gels, patches and plasters, are convenient and can avoid the first-pass effect of drugs.Rheological study, which describes the flow characteristics and mechanical properties of products relevant to their Critical Quality Attributes, has become the main focus for topical preparations.Liquid and solid behaviors of products are usually investigated via steady rheology as well as dynamic rheology.This article reviews the research on topical preparations for skin and the data analysis models based on two rheological methods, aiming to provide some references for the rheological evaluation of topical preparations.