Gary Drug Stores Inc., the new owner of the Drug Fair retail chain, is planning a major expansion in the area and more emphasis on healthcare and cosmetic goods, Gray Chairman Jerome A. Weinberger said yesterday.

In addition, Weinberger sought to explain the immediate firing of about 30 Drug Fair employees when the Washington chain was taken over by Gary last Thursday, after a vote by Drug Fair stockholders.

Weinberger said some of the employes -- mostly executives and their staffs -- were not told before the merger on Thursday that they would be dismissed but he said that not telling them beforehand was standard procedure. In any merger, it is likely some employes will be laid off, and "it was not a reflection on their capability as individuals," Weinberger said. "

Weinberger said that 30 of more than 5,200 employes were the only ones affected by dismissal notices.

Looking ahead, the Cleveland company plans to add more stores in the Washington area and would like to locate some within the District, Weinberger said. But rents within the city are very high, and the company is reviewing possible sites in the city and suburbs.

The drug chain, however, doesn't plan to venture into dental or eyeglasses services such as the Peoples Drug chain has, Weinberger said. Instead, Drug Fair stores will concentrate more on health and beauty aids, which "we still feel are the heart of the drug store business."

"There's potential there that's been overlooked," Weinberger said. The previous management didn't do as well in health, beauty, phramaceuticals and private-label promotions as it could have, he asserted.

Gray Drugs President Frederick W. Barney said the company plans to expand into the geographic gap between the Gray drug stores in Florida and the Drug Fair stores in the Washington area.

The Drug Fair name will remain on the stores, but Barney said yesterday the Drug Fair brands will be relabeled to include the Gray Drug name, and the line of products offered will be expanded.