Capsules could some day replace intramuscular injections for people with vitamin B12 deficiency, a U.S. company says.

Doctors rely on shots for people with a severe B12 deficiency —- sometimes elderly patients or strict vegetarians —- because of the poor performance of current oral formulations.

The injections are preferred because capsules are difficult to break down in the gastrointestinal tract and very little of the nutrient is absorbed into the bloodstream.

Studies have shown only about one per cent of a vitamin B12 tablet is absorbed, according to the U.S. biopharmaceutical company involved in developing an alternative treatment.

Emisphere Technologies, Inc. of New York state says studies have shown its new oral solid formulation brings vitamin B12 absorption to a range of seven to 30 per cent.

The company says it has developed synthetic chemical compounds that act as delivery agents or "carriers" to help therapeutic macro-molecules cross cell membranes without altering the drug molecule's chemical form or the integrity of the membrane.

Emispherre Technologies CEO Michael Novinski says the technology puts poorly absorbed molecules together with the carriers or "chaperones," but the two are not bound together. Once the transfer is complete, he said, the layer of gastric cells very quickly resumes its normal state.

Animal testing of the new treatment delivery system has been completed and researchers are now conducting human studies.