Three men, including a District of Columbia policeman, and one woman were arrested yesterday at the Rockville Ramada Inn in a drug raid that netted police more than $200,000 worth of illegal drugs, Montgomery County policy said.

The four allegedly had been selling drugs from the two rooms in the hotel for the last three days, police said.

About 50,000 Quaalude pills, the largest amount ever seized in the Washington area, were among the drugs recovered in the raid, police said. About $17,000 worth of cocaine and $5,500 in cash also were seized, police said.

According to county Police Chief Robert diGrazia, the fourth floor of the hotel had to be quietly cleared of guests prior to the raid because of police concern over the reported presence of a D.C. police officer in one of the rooms where the drug transactions allegedly were occuring.

No one was injured during the raid, police said.

The police officer was identified as James R. Chisholm, 29, of 4618 Creekshore Dr., Rockville. D.C police officials said Chisholm is assigned to the third district and has been on light duty for three weeks after undergoing surgery.After the arrest, Chisholm was placed on administrative leave with pay, police said.

All four of the those arrested were charged with possession with intent to distribute cocaine and Quaaludes, and Chisholm also was charged with being armed during a felony, police said. D.C. police officers are required to carry their service revolvers while not on duty.

Undercover policemen approached the rooms posing as drug purchasers yesterday afternoon, police said, and then made the arrests. The drug sales operation had been under investigation for a week, they said.

The other three arrested were Steven George Graham, 31, a clothing salesman at the Rockville Mall, at 12711 Robindale Dr., Rockville; Marlene Robinson Matthews, a housewife, of 14 Eldwick Ct., Potomac; and Larry Dale Butcher, 30, and unemployed car salesman from Ft. Lauderdale, Fla. Butcher also was charged with maintaining a common nuisance - the illegal drug operation - in a public place.