Acesulfame Potassium

Acesulfame Potassium
1 Nonproprietary Names
PhEur: Acesulfamum kalicum
2 Synonyms
Acesulfame K; E950; 6-methyl-3,4-dihydro-1,2,3-oxathiazin-
4(3H)-one 2,2-dioxide potassium salt; Sunett; Sweet One.
3 Chemical Name and CAS Registry Number
6-Methyl-1,2,3-oxathiazin-4(3H)-one-2,2-dioxide potassium
salt [55589-62-3]
4 Empirical Formula and Molecular Weight
C4H4KNO4S 201.24
5 Structural Formula
6 Functional Category
Sweetening agent.
7 Applications in Pharmaceutical Formulation
or Technology
Acesulfame potassium is used as an intense sweetening agent in
cosmetics, foods, beverage products, table-top sweeteners,
vitamin and pharmaceutical preparations, including powder
mixes, tablets, and liquid products. It is widely used as a sugar
substitute in compounded formulations,(1) and as a toothpaste
sweetener.(2)
The approximate sweetening power is 180–200 times that
of sucrose. It enhances flavor systems and can be used to mask
some unpleasant taste characteristics.
8 Description
Acesulfame potassium occurs as a colorless to white-colored,
odorless, crystalline powder with an intensely sweet taste.
9 Pharmacopeial Specifications
See Table I.
Table I: Pharmacopeial specifications for acesulfame potassium.
Test PhEur 2005
Characters þ
Identification þ
Appearance of solution þ
Acidity or alkalinity þ
Acetylacetamide þ
Impurity B and related substances 420 ppm
Fluorides 43 ppm
Heavy metals 45 ppm
Loss on drying 41.0%
Assay 99.0–101.0%
SEM: 1
Excipient: Acesulfame potassium
Magnification: 150

Voltage: 5kV
10 Typical Properties
Bonding index: 0.007
Brittle fracture index: 0.08(3)
Flowability: 19% (Carr compressibility index)(3)
Density (bulk): 1.04 g/cm3(3)
Density (tapped): 1.28 g/cm3(3)
Elastic modulus: 4000MPa(3)
Melting point: 2508C
Solubility: see Table II.
Specific volume: 0.538 cm3/g(4)
Tensile strength: 0.5MPa(3)
Viscoelastic index: 2.6(3)
11 Stability and Storage Conditions
Acesulfame potassium possesses good stability. In the bulk
form it shows no sign of decomposition at ambient temperature
over many years. In aqueous solutions (pH 3.0–3.5 at 208C) no
reduction in sweetness was observed over a period of
approximately 2 years. Stability at elevated temperatures is
good, although some decomposition was noted following
storage at 408C for several months. Sterilization and pasteurization
do not affect the taste of acesulfame potassium.(5)
The bulk material should be stored in a well-closed
container in a cool, dry place.
12 Incompatibilities
—
13 Method of Manufacture
Acesulfame potassium is synthesized from acetoacetic acid tertbutyl
ester and fluorosulfonyl isocyanate. The resulting
compound is transformed to fluorosulfonyl acetoacetic acid
amide, which is then cyclized in the presence of potassium
hydroxide to form the oxathiazinone dioxide ring system.
Because of the strong acidity of this compound, the potassium
salt is produced directly.
An alternative synthesis route for acesulfame potassium
starts with the reaction between diketene and amidosulfonic
acid. In the presence of dehydrating agents, and after
neutralization with potassium hydroxide, acesulfame potassium
is formed.
14 Safety
Acesulfame potassium is widely used in beverages, cosmetics,
foods, and pharmaceutical formulations and is generally
regarded as a relatively nontoxic and nonirritant material.
Pharmacokinetic studies have shown that acesulfame potassium
is not metabolized and is rapidly excreted unchanged in
the urine. Long-term feeding studies in rats and dogs showed no
evidence to suggest acesulfame potassium is mutagenic or
carcinogenic.(6)
The WHO has set an acceptable daily intake for acesulfame
potassium of up to 15 mg/kg body-weight.(6)
LD50 (rat, IP): 2.2 g/kg(5)
LD50 (rat, oral): 6.9–8.0 g/kg
15 Handling Precautions
Observe normal precautions appropriate to the circumstances
and quantity of material handled. Eye protection, gloves, and a
dust mask are recommended.
16 Regulatory Status
Included in the FDA Inactive Ingredients Guide for oral and
sublingual preparations. Included in the Canadian List of
Acceptable Non-medicinal Ingredients. Accepted for use in
Europe as a food additive. It is also accepted for use in certain
food products in the USA and several countries in Central and
South America, the Middle East, Africa, Asia, and Australia.
17 Related Substances
Alitame.
18 Comments
The perceived intensity of sweeteners relative to sucrose
depends upon their concentration, temperature of tasting, and
pH, and on the flavor and texture of the product concerned.
Intense sweetening agents will not replace the bulk, textural,
or preservative characteristics of sugar, if sugar is removed from
a formulation.
Synergistic effects for combinations of sweeteners have been
reported, e.g., acesulfame potassium with aspartame or sodium
cyclamate. A ternary combination of sweeteners that includes
acesulfame potassium and sodium saccharin has a greater
decrease in sweetness upon repeated tasting than other
combinations.(7)
Note that free acesulfame acid is not suitable for use as a
sweetener.
A specification for acesulfame potassium is contained in the
Food Chemicals Codex (FCC).
19 Specific References
1 Kloesel L. Sugar substitutes. Int J Pharm Compound 2000; 4(2):
86–87.
2 Schmidt R, Janssen E, Haussler O, et al. Evaluating toothpaste
sweetening. Cosmet Toilet 2000; 115: 49–53.
3 Mullarney MP, Hancock BC, Carlson GT, Ladipo DD. The
powder flow and compact mechanical properties of sucrose and
three high-intensity sweeteners used in chewable tablets. Int J
Pharm 2003; 257: 227–236.
4 Birch GG, Haywood KA, Hanniffy GG, et al. Apparent specific
volumes and tastes of cyclamates, other sulfamates, saccharins and
acesulfame sweeteners. Food Chemistry 2004; 84: 429–435.
5 Lipinski G-WvR, Huddart BE. Acesulfame K. Chem Ind 1983; 11:
427–432.
6 FAO/WHO. Evaluation of certain food additives and contaminants.
Thirty-seventh report of the joint FAO/WHO expert
committee on food additives. World Health Organ Tech Rep Ser
1991; No. 806.
7 Schiffman SS, Sattely-Miller EA, Graham BG, et al. Effect of
repeated presentation on sweetness intensity of binary and tertiary
mixtures of sweetness. Chem Senses 2003; 28: 219–229.
20 General References
Anonymous. Artificial sweetners. Can Pharm J 1996; 129: 22.
Lipinski G-WvR, Lu¨ ck E. Acesulfame K: a new sweetener for oral
cosmetics. Manuf Chem 1981; 52(5): 37.
Marie S. Sweeteners. In: Smith J, ed. Food Additives User’s Handbook.
Glasgow: Blackie, 1991: 47–74.
Nutrinova. Technical literature: Sunett in Pharmaceuticals, 1998.
21 Authors
JH Chu.
22 Date of Revision
12 August 2005.
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