BIOAVAILABILITY OF GENERIC DRUGS

Generic drugs are copies made from an already existing template of a particular medication. They do not pass through testing, innovation and approval like the original drugs on which they are based did. They are produced after the patent on an original drug has expired, after which drug manufacturing companies can apply to get approval to produce these drugs at a cheaper rate.

Generic drugs are common because of their availability and relatively cheap cost. The manufacturers do not have to spend money and time on the drug innovation and development, and so they are produced chiefly to be more accessible. This is why most doctors and patients prefer the generic drugs, because they save money.

There are, however, some concerns raised when it comes to the consumption of these drugs. "This is why they have to undergo rigorous testing and approval by the FDA before they can be deemed a safe alternative to a name brand medication".
http://groupspaces.com/BIOAVAILABILITY/

Evaluating the bioavailability and bioequivalence of generic medications.

 By law, the U.S. Food and Drug Administration (FDA) is permitted to approve generic versions of brand-name medications without necessarily requiring that research be conducted to prove them safe and effective, provided that a number of criteria are met. The most important criterion is bioequivalence. Bioavailability refers to the rate and extent to which the active ingredient is absorbed from a drug product. Maximum drug concentration (Cmax) is the parameter used to characterize the absorption rate. The area under the plasma drug concentration-time curve (AUC) is the parameter used to characterize the extent of drug absorption. Bioequivalence means that there is an equivalent rate and extent of absorption of the same active ingredient from two or more drug products. For a generic drug to be approved, both Cmax and AUC must vary only within a certain limited range compared with those for the brand name medication. Information about generic and pharmaceutical alternative drugs can be found in the Orange Book and via Drugs@FDA.

https://www.ncbi.nlm.nih.gov/pubmed/20102127