The drug development process is complex and comprehensive, requiring preclinical testing, investigational new drug (IND) applications, and completed clinical testing before marketing approval from the FDA. Generally, new drug applications (NDAs) or biologics license applications (BLAs) are reviewed comprehensively before approval. After the drugs are approved for the domestic market, it is critical to continually monitor their safety and efficacy in post-marketing studies.

The stages of drug development is complicated, and needs to undergo a rigorous medical evaluation. Generally, a drug needs to be sent through specific regulatory procedures undertaken before marketing approval from the FDA is obtained (FDA). After successful marketing, drug performance is monitored continuously for safety and efficacy. Most drugs in the pipeline get exhausted before reaching the market. The drugs that do make it are subject to additional post-market studies.

The drug development process is difficult, with many challenges from clinical testing to post-marketing studies before entry into the market. Getting a treatment new drug (IND) application approved by the FDA is primarily a team effort between NIH and pharmaceutical companies, which together strive to improve public health. A lot of scientific investigation goes on before reaching the mark at market entry, and getting a candidate drug to that stage is exciting. It starts with preclinical testing, clinical trials in patients, and then further clinical evaluation before release in the market place.

Bioavailability and bioequivalence studies play an important role in the development and approval of generic drugs. A multitude of factors affect the absorption of drugs including dosage form, formulation excipients, site of drug administration, disease state and concomitant medications. Bioequivalence studies are conducted to demonstrate that the therapy from different generic drugs have equivalent bioavailability when measured in the same manner.

Bioavailability definition is the rate and extent to which an active substance or other substance from a drug product absorbed into the bloodstream/circulation and becomes available at the site of action. Bio-equivalence is the sameness in clinical effect between two drugs on the basis of pharmacokinetics (PK), i.e., how fast the body absorbs, metabolizes, and excretes a drug and its metabolites. Bioavailability and bioequivalence studies are two important considerations in market approval of generic drugs, with special requirements for generic applicability and biological intermediates determinations if needed.

The bioavailability of a drug refers to the rate and extent at which the active drug ingredient or metabolite becomes available at the site of action following administration of the drug. Bioavailability is one of the most important factors affecting pharmacokinetics and drug efficacy. Bioequivalence studies are studies undertaken to establish whether two generic drugs are similar enough in their dosage forms, strength, route of administration and excipients to be considered therapeutically equivalent.

Bioavailability of a drug refers to its movement in your body and its active components, while bioequivalence denotes the quality of two drugs. In other words, the goal of a bioequivalence study is to ensure that another product is not just identical to but also equivalent to your product.