INTRODUCTION

Parenterally administered drugs include injections that are administered through the external boundary tissue with subsequent immediate release or extended release of the drug substance into the circulatory system. Parenteral drugs also include drug preparations that are administered by placement within the body to achieve, for instance, extended release of drug substance at a local area. Immediate and modified-release parenteral drug products exist as injections (solutions, suspensions, emulsions) and implants. Immediately prior to administration, the parenteral drug preparation may be reconstituted from sterile powders to form solutions, suspensions, or emulsions. Such parenteral drug preparations also include drug/device combinations such as stents. Generally, performance tests, as discussed in this chapter, are not required for aqueous solutions.