Metabolism and pharmacokinetics of sucrose acetate isobutyrate (SAIB) and sucrose octaisobutyrate (SOIB) in rats, dogs, monkeys or humans: a review.

Sucrose acetate isobutyrate (SAIB), a mixture of esters of sucrose with a composition approximating the name sucrose diacetate hexaisobutyrate, has been used for over 30 years in many countries as a 'weighting' or 'density-adjusting' agent in non-alcoholic carbonated and non-carbonated beverages. As part of the demonstration of safety of SAIB as a direct food additive in human diets, a number of metabolism and pharmacokinetic studies have been carried out on SAIB and the constituent compound sucrose octaisobutyrate (SOIB). These studies are reviewed here in order to present in one volume a complete picture of the safety studies that have been done on SAIB relevant to its use as a direct food additive. The metabolism and pharmacokinetic studies in rats, dogs and humans show that SAIB is extensively metabolized in the gastrointestinal tract, probably to sucrose and partially acylated sucrose. Partially acylated sucrose appears, along with sucrose, to be readily absorbed from the gut, perhaps with inversion, although a considerable portion of ingested SAIB and partially deesterified SAIB is eliminated in the faeces. The absorbed materials are readily eliminated in the urine and the bile or, after further metabolism, as carbon dioxide and water. SOIB is less readily metabolized in the gut of rats, dogs and monkeys than is SAIB, suggesting that the presence of acetyl groups facilitates the metabolism of fully acylated sucrose. In toto, the studies suggest that humans handle SAIB more like rats than like dogs.