ABSTRACT
Injectable products have and will continue to be an important component in the medication management of patients for cancer, acute cardiovascular disease, infection, central nervous system disorders, and traumatic injuries. This chapter provides pharmaceutical scientists with a general overview of available in vitro and in vivo methods in animals to screen drugs, excipients, and formulations for their potential to cause tissue damage and pain. It is critical to understand the key definitions with respect to tissue damage and/or pain associated with injectables. Tissue damage can be defined as a formulation-induced reversible or irreversible change in the anatomy, biochemistry, or physiology at the injection site. Pain upon injection involves the activation of nociceptors at the injection sites. Three types of nociceptors seem to be involved primarily with pain upon injection and involve chemical, thermal, or mechanical sensitivity.
