Agnes Varis, a daughter of threadbare immigrants who parlayed a chemistry degree and $50,000 into a profitable drug company, and in so doing became a prolific philanthropist whose causes included the Democratic Party, access to generic drugs and access to opera, died Friday at her home in Manhattan. She was 81.

The cause was cancer, said her cousin Ted Leonsis, an entrepreneur who owns the Washington Capitals hockey team and the Washington Wizards basketball team.

Varis, a leading figure in the generic-drug industry, was the founder and longtime chief executive of Agvar Chemicals, based in Little Falls, N.J. The company supplies active ingredients to international drug makers — in particular the makers of generic drugs. Privately held, Agvar has annual revenues between $50 million and $100 million, Bloomberg News reported in March.

A major Democratic contributor, Varis gave the party’s candidates millions of dollars over the years.