Bioequivalence and Bioavailability Forum

Hi Hema!

❝ What is the difference between Innovators and Generic product. Just explain me in detailed by giving some suitable sites information if you can.

You are at the right site anyway

An innovator got an approval for his product by demonstration of efficacy and safety (clinical phases II-III); clinical phase IV occurs after approval. For his (in some cases disputable) innovate efforts he is granted the exclusive rights to market this compound/product for a couple of years (patent of the drug: generally 20 years, but may be differ from country to country - leaving 10-12 years after market authorization).

After this period of time, other - generic - companies may get an 'abbreviated' approval. If they demonstrate bioequivalence of their (generic) product, they may also marketed their product - generally at a cheaper price (because they did not have the development costs of a new compound, and the large efficacy/safety studies).
The main assumption in bioequivalence (BE) is: if the blood- (plasma-, serum-,…) levels are 'superimposable', the concentration at the site of action (e.g., at a receptor) is also the same and therefore yielding the same pharmacodynamic response. Although this is only an assumption (we cannot take samples from brain tissue to check to concentration of an antiepileptic), it's a well founded one.
The concept of BE is common practice for more than 25 years now and, besides some anecdotal reports, there is no reason to believe that there is a difference in efficacy/safety between innovator and generic products.

For an explanantion in statistical terms have a look at Helmut's post.
A collection of national and international guidances is also available at this site.

See also Wikipedia on Bioequivalence and Generics.
A wonderful collection of knowledge is David Bourne's PK/PD-Site.

Best regards,
Hermann