Peoples Drug Stores Inc. yesterday reported a 27 percent rise in profits for its fiscal year ended Sept. 27. At the same time, the drug store chain's fourth-quarter profits rose by 36 percent.

For the year, Peoples' profits rose to $8.17 million ($2.17 a share), up from $6.45 million ($1.77) for fiscal 1979, while fourth-quarter profits rose to $2.19 million (57 cents) this year, compared with $1.61 million (44 cents) for the same period in 1979.

Peoples' sales for fiscal 1980 rose by 27 percent, to $561.83 million, up from sales of $441.11 million for last year. Fourth-quarter sales rose 30 percent, to $133.71 million.

Company Chairman Adrian Israel and President Sheldon Fantle said in a joint statement that Peoples' performance "was achieved in spite of the fact that 1980 was an unusually difficult year for our nation's economy

"It is particularly noteworthy in view of extremely high interest rates and the substantial increase in our LIFO accounting provision in fiscal 1980, which was $6.129 million this year versus $3.659 million last year before taxes," they noted.

In other reports, B.F. Saul Real Estate Investment Trust reported profits of $8.36 million ($1.42 a share) for the fiscal year that ended Sept. 30, compared with a loss of $2.76 million for the year. Cash flow from operations was $12.7 million, compared with $249,000 last year, the company said.

The improvement stemmed primarily from an increase in condominium profits, which totaled $15.94 million in 1980, compared with $2.06 million last year, the Chevy Chase company reported.

For the fourth quarter, the trust reported a profit of $3.23 million (55 cents), compared with a loss of $2.13 million for the same period last year.

Washington Real Estate Investment Trust Co. reported third-quarter profits of $817,840 (54 cents a share) compared to profits of $748,502 (49 cents) for the same quarter last year. For the first three quarters, profits rose to $2.5 million ($1.61), compared to $2.2 million ($1.46) for the same period in 1979.