GAMMA CYCLODEXTRIN – JECFA SPECIFICATION
| Prepared at the 53rd JECFA (1999) and published in FNP 52 Add 7 (1999), superseding specifications prepared at the 51st JECFA (1998), published in FNP 52 Add 6 (1998). ADI “not specified”, established at the 53rd JECFA in 1999. | |
| SYNONYMS | gamma-cyclodextrin, gamma-CD, cyclooctaamylose, cyclomaltooctaose |
| DEFINITION | A non-reducing cyclic saccharide consisting of eight alpha-1,4-linked D-glucopyranosyl units manufactured by the action of cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) on hydrolysed starch followed by purification of the gamma -cyclodextrin. Purification is carried out using one of the following procedures: precipitation of a complex of gamma-cyclodextrin with a macrocyclic compound and subsequent extraction with n-decane followed by steam-stripping of the solvent; crystallization from the purified mother liquor containing gamma-cyclodextrin obtained by chromatographic methods with ion exchange or gel filtration; membrane separation methods such as ultra filtration and reverse osmosis. |
| Chemical names | Cyclooctaamylose |
| C.A.S. number | 17465-86-0 |
| Chemical formula | (C6H10O5)8 |
| Structural formula |  |
| Formula weight | 1297 |
| Assay | Not less than 98% on an anhydrous basis |
| DESCRIPTION | Virtually odourless, white or almost white crystalline solid |
| FUNCTIONAL USES | Carrier, flavour modifier, stabilizer |
| CHARACTERISTICS | |
| IDENTIFICATION | |
| Solubility (Vol.4) | Freely soluble in water; very slightly soluble in ethanol |
| Specific rotation (Vol.4) | [alpha]25D: Between +173 and +180o (1% solution) |
| Reaction with iodine (Vol.4) | To 0.2 g of the sample in a test-tube add 2 ml of a 0.1 N iodine solution. Heat the mixture in a water bath and allow to cool at room temperature. A clear brown solution is formed. |
| Chromatography | The retention time for the major peak in a liquid chromatogram of the sample corresponds to that for gamma-cyclodextrin in a chromatogram of reference gamma-cyclodextrin (available from Consortium für Elektrochemische Industrie GmbH, München, Germany or Wacker Biochem Group, Adrian, MI, USA) using the conditions described in the METHOD OF ASSAY. |
| PURITY | |
| Water (Vol.4) | Not more than 11% (Karl Fischer Method) |
| Volatile organic compounds | Not more than 20 mg/kgSee description under TESTS |
| Reducing substances (Vol.4) | Not more than 0.5% (as glucose) |
| Sulfated ash (Vol.4) | Not more than 0.1% |
| Lead (Vol.4) | Not more than 1 mg/kgReflux about 5 g of the sample, accurately weighed, with 30 ml nitric acid for 1 h. Remove the reflux condenser and attach a condenser to the flask. Continue to heat and collect the distilled nitric acid. Allow the residue to cool, add 20 ml of water and again allow to cool. Add 2 ml of orthophosphoric acid, dilute to 100 ml and determine the lead content of the solution by atomic absorption spectroscopy (FNP 5). |
| TESTS | |
| PURITY TESTS | |
| Volatile organic compounds | Dissolve 50 g of the sample in about 700 ml distilled water in a 1-litre round bottom flask and add a magnetic stirrer. Attach the flask to the lower part of a Bleidner apparatus (see Figure 1) and connect a 100-ml round bottom flask containing about 70 ml hexane and a few boiling stones to the other side of the apparatus. Fill the Bleidner apparatus with equal amounts of water and hexane and place a reflux condenser on the top. Heat both flasks with heating mantels to boiling. Stir the 1-litre flask well by the magnetic stirrer. Keep the content of the two flasks boiling for 8 h. After cooling remove the 100-ml flask and transfer the content to a 100 ml volumetric flask and fill to the mark with hexane. Figure 1 Analyze the hexane solution by gas chromatography using the following conditions:Column- length: 30 m- diameter: 0.32 mm- stationary phase: 95% dimethyl, 5% diphenyl polysiloxane, 0.25 µmInjector: 280°Temperature: 70° (4 min) – 250°, 10°/minCarrier- gas: nitrogen- flow: 70 ml/minDetection: FID, 280°Calculate the area(s) under the peak for each volatile organic compound and convert it to mg/kg gamma-cyclodextrin using the response factor of 8-cyclohexadecen-1-one. The response factor is determined from a calibration curve using 8-cyclohexadecen-1-one concentrations of 0.1-6 mg/100 ml hexane. |
| METHOD OF ASSAY | Determine by liquid chromatography using the following condition:Column- length: 30 cm- diameter: 7.8 mm i.d.- packing: Silver bonded to sulfonated divinyl benzene-styrene copolymer (Aminex HPX-42A (Bio-Rad Laboratories) or equivalent- particle size: 25 µmSolvent: waterFlow rate: 0.3 – 1.0 ml/minTemperature: 65 ± 10°Injection volume: 20 – 100 µlDetector: differential refractometerSample solution: weigh 1.0 g of the sample and dissolve in 100 ml of water.CalculationCalculate the content of gamma-cyclodextrin in the sample by the peak area percentage method using the following formula:A = (B / C) x 100whereA = percentage of gamma-cyclodextrin in the sampleB = peak area of gamma-cyclodextrin in the chromatogramC = the sum of the peak area of every peak recorded in the chromatogram |