Various dosage forms of drugs are used in therapy. Plants, animals, microorganisms, minerals, synthetic, semisynthetic, and biosynthetic are various sources of drugs. Drugs need to be presented in a form that can be administered to an organism. Formulation is a recipe by which a drug is prepared. Drug formulation can allows specific tissue sites to be selectively targeted or systemic absorption of the drug to be avoided. The administration of drugs is one of the most important and exacting duties performed in caring for sick and injured patients. The appropriate drug given in the correct dosage will very often hasten a patient’s recovery. On the other hand, an inappropriate drug or dosage may worsen a patient’s condition or even result in his death. A detailed discussion on the oral drugs, factors affecting oral route of administration, and oral-special preparations has been provided in this chapter.