ABSTRACT
In the evolution of drug development and manufacturing, drug delivery systems have risen to the forefront in the latest of pharmaceutical advances. There are many new pharmacological entities discovered each year, each with its own unique mechanism of action. Each drug will demonstrate its own pharmacokinetic profile. This profile may be changed by altering the drug delivery system to the target site. In order for a drug to demonstrate its pharmacological activity it must be absorbed, transported to the appropriate tissue or target organ, penetrate to the responding subcellular structure, and elicit a response or change an ongoing process. The drug may be simultaneously or sequentially distributed to a variety of tissues, bound or stored, further metabolized to active or inactive products, and eventually
excreted from the body. A delivery system that may have an effect upon the absorption, distribution, metabolism, or excretion of a pharmaceutical entity may then affect the potency, half-life, potential for drug interactions, and side-effect profile of that specific entity. Drug delivery systems are developed to enhance the desired pharmacological effect at specific target sites, while reducing the probability of drug interactions and unwanted side effects.
