Generic Drug

It is a medication that has exactly the same active ingredient as the brand-name drug and yields the same therapeutic effect.

It is the same in dosing, safety, strength, quality, the way it works, the way it is taken, and the way it should be used.

These similarities help to demonstrate bioequivalence, which means that a generic medicine works in the same way and provides the same clinical benefit as the brand-name medicine.

They also have the same risks and benefits as their brand-name counterparts.

Generic drugs do not need to contain the same inactive ingredients as the brand-name product.

A generic drug can only be marketed after the brand name drug's patent has expired.

Generic drugs are usually much less expensive than brand-name drugs.

Active Pharmaceutical Ingredients (APIs)

APIs are the active components in a pharmaceutical drug that produces the required effect on the body to treat a condition.

APIs are produced by processing chemical compounds.

In the context of drug development and manufacturing, APIs are the key active components that interact with specific receptors or target molecules in the body to bring about the desired physiological or therapeutic response

All drugs are made up of two core components:

1. Active Pharmaceutical Ingredient (API), which is the central ingredient, and 
2. Excipients.

Excipients

They are substances other than the drug that helps deliver the medication to your system.

Excipients are chemically inactive substances, such as lactose or mineral oil. 

Some of these materials are used to help the medication remain stable and to control absorption when you take the drug. 

Example: For instance, if you have a headache, acetaminophen is the API, while the liquid in the gel-capsule or the bulk of a pill is the excipient.