CHAPTER 8. Characterization Methods for Parenteral Peptide Controlled Release Drug Delivery Systems

The development of biodegradable controlled release drug delivery systems (CR-DDS) is an important tool to improve the therapeutic performance of peptide drugs. By means of CR-DDS it is possible to overcome the problem of short half-lives and to provide peptide release over several weeks to months. However, rational design and optimization requires an understanding of the drug-release processes and mechanisms. Therefore, appropriate characterization is required. This chapter discusses several characterization techniques that provide important information about key parameters in vitro and in vivo. It highlights the importance of the microenvironment inside the delivery matrix, and discusses how micropolarity, microviscosity and microacidity can be measured.