Dart Drug Corp., which recently spun off its lucrative Trak Auto and Crown Books subsidiaries, reported that consolidated earnings for its first quarter leaped 368 percent to $1.7 million from $467,000 in 1982.

Net income last year was bolstered by an extraordinary item, the sale of Trak West to Thrifty Stores, which contributed $8.3 million to Dart's bottom line. Net income for the quarter ended April 30 were $1.7 million ($1 a share), compared with $8.77 million ($5.27) last year.

Revenue at the Landover-based chain increased to $70.1 million from $62.2 million.

Dart holds controlling interest in Trak, which went public in late April, and Crown, which went public in early May, and that interest is included in Dart's earnings.

Penril Corp. of Rockville, a maker of diversified electronic equipment, posted nine-month earnings of $1 million (52 cents), compared with $1.4 million (70 cents) in 1982. Revenue slipped to $28.5 million from $29.2 million.

For the third quarter, Penril had earnings of $398,000 (20 cents), down sharply from profits of $576,000 (29 cents) last year. Revenue was down from $10.1 million to $9.7 million.