Lactitol

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Lactitol contains NLT 98.0% and NMT 101.0% of C₁₂H₂₄O₁₁, calculated on the anhydrous basis.

2 IDENTIFICATION

Change to read:

A. ▲Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K▲ (CN 1-May-2020)

3 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

(See Chromatography 〈621〉, System Suitability.)

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

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.5%

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: Dissolve 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.

5 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%.

6 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