A drug is a chemical. A dosage form is what you actually take. The same active ingredient can be delivered as a tablet, a capsule, a syrup, an injection, a patch, or an inhaler. The choice affects how fast the drug works, where it goes, and how easy it is to use. It also affects stability, taste, and cost.

Tablets are compressed powders, sometimes coated to mask taste or control release. Capsules hold powder or liquid in a shell. Syrups are sweetened liquids for patients who cannot swallow pills. Injections bypass absorption entirely and act within seconds. Patches deliver drug through the skin at a steady rate. Inhalers send drug directly to the lungs for asthma and COPD. Suppositories are inserted into the rectum or vagina for local or systemic effect. Each form has advantages and drawbacks, and the choice depends on the drug, the patient, and the condition.

Common dosage forms:

• Oral solids. Tablets, capsules, chewables.
• Oral liquids. Syrups, suspensions, solutions.
• Injectables. IV, IM, subcutaneous.
• Topicals. Creams, ointments, gels, patches.
• Others. Inhalers, suppositories, eye drops, nasal sprays.

Some drugs come in multiple forms. Morphine, for example, is available as a tablet, a liquid, an injection, and a suppository, each with its own onset and duration.