Purepac Pharmaceutical Co

Palo Alto-based Syntex Corp. on Wednesday faced another potential challenger to its monopoly on Naprosyn, the company's blockbuster arthritis drug. Purepac Inc. of Elizabeth, N.J., said its Purepac Pharmaceutical Co. won tentative approval from the Food and Drug Administration to sell naproxen, a generic version of Naprosyn. Naprosyn and another naproxen-based drug, Anaprox, generated $928 million of Syntex's $2.12 billion in worldwide sales for the year ended July 31.

Palo Alto-based Syntex Corp. on Wednesday faced another potential challenger to its monopoly on Naprosyn, the company's blockbuster arthritis drug. Purepac Inc. of Elizabeth, N.J., said its Purepac Pharmaceutical Co. won tentative approval from the Food and Drug Administration to sell naproxen, a generic version of Naprosyn. Naprosyn and another naproxen-based drug, Anaprox, generated $928 million of Syntex's $2.12 billion in worldwide sales for the year ended July 31.