Biospherics Inc. announced yesterday that it has found a sweet and cheap way to produce a noncaloric, nonartificial sugar substitute it has developed.

The Rockville-based company said it has entered into an exclusive agreement with Boise Cascade Corp. for a process that will enable Biospherics to produce the sugar substitute for less than $2 a pound; production costs once were estimated at $1,000 a pound.

The production process, developed independently by Boise Cascade, "constitutes the most remarkable reduction in potential product cost since Biospherics began its development program last year," the company said. "It's the first process we have identified that holds promise for the economic production of an L-sugar in large quanity," added Biospherics President Gilbert Levin.

More than a year ago, Biospherics announced that it had received a patent for L-sugar, or "left-handed sugar," so called because its molecules are arranged in a mirror image of conventional sugar. Because the left-handed sugars are rarely found in nature, Biospherics believes that they can't be absorbed by the human body. Thus, although the sugar will taste just as sweet as conventional sugar, Biospherics believes it will not be fattening, cause tooth decay or harm diabetics.

The Food and Drug Administration still must rule on whether the sugar is effective and safe--a process Levin said will take at least three years.

Biospherics has been studying ways to make L-sugar economically. Until the agreement with Boise Cascade, Levin said the company had no real prospect of getting L-sugar produced for less than $1,000 a pound. Although the $2-a-pound price is much better, Levin noted that sugar sells in bulk on the commodity markets for about 15 cents a pound. Given that, "We hope there will be further improvements to again reduce costs," he said.

Under the agreement, Biospherics will have an exclusive license from Boise Cascade to produce commercial quantities of a chemical compound developed by Boise Cascade that with one additional step, can be converted into L-sugar. Levin declined to specify the chemical compound, saying that, under the agreement with Boise Cascade, the compound could not be named until a patent is issued for it; that is expected later this year. He noted that the compound can be made from corn and other cheap feedstocks.