Methods for the Performance Evaluation of External Foaming Agents

External foaming agents, a new kind of drug delivery system with many advantages, including large application area, strong adhesion, convenient application and small irritation, have developed rapidly in recent years. Their performance evaluation method and evaluation index are of great significance to the research of formulation and process development of foam agent. This paper has reviewed some performance evaluation methods of external foaming agents, so as to provide references for their further development.