Analysis of liposomes

Liposomes are highly versatile structures for research, therapeutic, and analytical applications. In order to assess the quality of liposomes and obtain quantitative measures that allow comparison between different batches of liposomes, various parameters should be monitored. For liposomes used in analytical and bioanalytical applications, the main characteristics include the average diameter and degree of size polydispersity; encapsulation efficiency; the ratio of phospholipids to encapsulant concentration; lamellarity determination. A detailed description of today's most commonly used methods and of novel techniques for the quantification of these aspects is presented in this report citing 182 references. Their advantages and limitations are discussed where appropriate in order to provide the reader with an understanding of the current state of the art assessment of liposome quality.