Lactitol
(lak' ti tol).
Click to View Image

C12H24O11 344.31

C12H24O11·H2O 362.34

C12H24O11·2H2O 380.35
4-O--d-Galactopyranosyl-d-glucitol     [585-86-4].
Monohydrate     [81025-04-9].
Dihydrate     [81025-03-8].
DEFINITION
Lactitol contains NLT 98.0% and NMT 101.0% of C12H24O11, calculated on the anhydrous basis.
IDENTIFICATION
ASSAY
•  Procedure
Mobile phase:  Water
Standard solution:  10.0 mg/mL of USP Lactitol RS
Sample solution:  10.0 mg/mL of Lactitol
Chromatographic system 
Mode:  LC
Detector:  Refractive index
Column:  7.8-mm × 30-cm; packing L34
Column temperature:  85
Flow rate:  0.7 mL/min
Injection size:  25 µL
System suitability 
Sample:  Standard solution
Suitability requirements 
Relative standard deviation:  NMT 1.0% for lactitol
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of lactitol (C12H24O11) in the portion of Lactitol taken:
Result = (rU/rS) × (CS/CU) × 100
rU == peak response from the Sample solution
rS == peak response from the Standard solution
CS == concentration of USP Lactitol RS in the Standard solution (mg/mL)
CU == concentration of Lactitol in the Sample solution (mg/mL)
Acceptance criteria:  98.0%–101.0% on the anhydrous basis
IMPURITIES
•  Residue on Ignition 281: NMT 0.5%
•  Heavy Metals 231
Test preparation:  Dissolve 4 g in 25 mL of water.
Acceptance criteria:  NMT 5 ppm
•  Related Compounds
Standard solution:  0.3 mg/mL of USP Lactitol RS
Sample solution:  Prepare as directed in the Assay.
Chromatographic system:  Proceed as directed in the Assay.
System suitability 
Sample:  Standard solution
[Note—The relative retention times for lactose, glucose, galactose, lactulitol, lactitol, galactitol, and sorbitol are about 0.53, 0.58, 0.67, 0.72, 1.0, 1.55, and 1.68, respectively. ]
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentages of galactitol, sorbitol, lactulitol, lactose, glucose, and galactose in the portion of Lactitol taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response of the relevant related compound, if observed, from the Sample solution
rS== peak response of lactitol from the Standard solution
CS== concentration of USP Lactitol RS in the Standard solution (mg/mL)
CU== concentration of Lactitol in the Sample solution (mg/mL)
Acceptance criteria:  The total of the percentages of all related compounds is NMT 1.5%.
•  Reducing Sugars
Standard solution:  Pipet 2 mL of a dextrose solution containing 0.5 mg/mL into a 10-mL conical flask.
Sample solution:  Disolve 500 mg in 2.0 mL of water in a 10-mL conical flask.
Analysis:  Concomitantly add 1 mL of alkaline cupric tartrate TS to each solution, heat to boiling, and cool.
Acceptance criteria:  NMT 0.2%, calculated as dextrose. The Sample solution shows no more turbidity than that produced in the Standard solution, in which a reddish brown precipitate forms.
SPECIFIC TESTS
•  Water Determination, Method I 921: For the monohydrate form, 4.5%–5.5%; for the dihydrate form, 9.5%–10.5%; and for the anhydrous form, NMT 0.5%.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers.
•  Labeling: Label it to indicate whether it is the monohydrate, the dihydrate, or the anhydrous form.
•  USP Reference Standards 11
USP Lactitol RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
1-301-816-8335
(EXC2010) Monographs - Excipients
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 1836
Pharmacopeial Forum: Volume No. 31(4) Page 1143