The company has maintains 3,800 marketing authorization licenses for 630 different pharmaceutical products, classified in over 10 therapeutic categories.

Drug plans do not have to cover every drug, but are supposed to cover at least two in each therapeutic category and class.

Under the law, insurers have to cover "drugs in all therapeutic categories and classes," but not necessarily every drug in every class.

But no manufacturer makes drugs in every therapeutic category, from antidepressants to ulcer treatments.

It offers a range of complementary products in each therapeutic category so that customers have more choices to suit their needs.

In each therapeutic category, it also offers high margin private label products.

Mr. Mehta said he believes it is now more useful to divide the companies by therapeutic categories, like cardiovascular, inflammation or cancer.

A broad therapeutic category, like antihistamines or heart medications, typically includes several classes.

Potentially life-saving drugs, for instance cancer treatments, fell into a high therapeutic category.

A broad therapeutic category like heart medications, painkillers or gastrointestinal drugs typically includes several classes.