Parenteral refers to medication administered in a manner other than the digestive system.
There are many different routes of drug administration that fall into the Parenteral category. Mostly in the form of quick injection for medication. However sometimes the medicine or fluid is slowly administered over many hours. The bioavailability of parenteral preparation is 100 % because they are not undergone for the Absorption , Distribution , Metabolism and excretion processes. These kind of medicines are known as parenteral drugs. (i.e. Para+enteral)