International Numbering System (INS) for Food Additives: 953
Food additives Europe numbers: E953
Functional Category
Coating agent; granulation aid; medicated confectionary base; sweetening agent; tablet and capsule diluent.
Applications in Pharmaceutical Formulation
Isomalt is a noncariogenic excipient used in a variety of pharmaceutical preparations including tablets or capsules, coatings, sachets, and suspensions, and in effervescent tablets. It can also be used in direct compression and wet granulation.(1) In buccal applications such as chewable tablets it is commonly used because of its negligible negative heat of solution, mild sweetness, and ‘mouth feel’. (2,3) It is also used widely in lozenges, sugar-free chewing gum, and hard-boiled candies, and as a sweetening agent in confectionery for diabetics.
Description
Isomalt is a sugar alcohol (polyol) that occurs as a white or almost white powder or granular or crystalline substance. It has a pleasant sugarlike taste with a mild sweetness approximately 50–60% of that of sucrose.(2–
Stability and Storage Conditions
Isomalt has very good thermal and chemical stability. When it is melted, no changes in the molecular structure are observed. It exhibits considerable resistance to acids and microbial influences.(1) Isomalt is non-hygroscopic, and at 258C does not significantly absorb additional water up to a relative humidity (RH) of 85%; paracetamol (acetaminophen) tablets based on isomalt were stored for 6 months at 85% RH at 208C and retained their physical aspect.(1) If stored under normal ambient conditions, isomalt is chemically stable for many years. When it is stored in an unopened container at 208C and 60% RH, a re-evaluation after 3 years is recommended. Isomalt does not undergo browning reactions; it has no reducing groups, and therefore it does not react with other ingredients in a formulation (e.g. with amines in Maillard reactions).
Safety
Isomalt is used in oral pharmaceutical formulations, confectionery, and food products. It is generally regarded as a nontoxic, nonallergenic, and nonirritant material. Toxicological and metabolic studies on isomalt(5–10) have been summarized in a WHO report prepared by the FAO/WHO Expert Committee (JECFA), resulting in an acceptable daily intake of ‘not specified’. (11) The glycosidic linkage between the mannitol or sorbitol moiety and the glucose moiety is very stable, limiting the hydrolysis and absorption of isomalt in the small intestine. There is no significant increase in the blood glucose level after oral intake, and glycemic response is very low, making isomalt suitable for diabetics. The majority of isomalt is fermented in the large intestine. In general, isomalt is tolerated very well, although excessive consumption may result in laxative effects.(12–14) Isomalt is not fermented by bacteria present in the mouth; therefore no significant amount of organic acid is produced that attacks tooth enamel.(15–17)