Lactitol
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C12H24O11. 344.31

4-O-b-D-Galactopyranosyl-D-glucitol [585-86-4].

Monohydrate. 362.34 [81025-04-9].

Dihydrate. 380.35 [81025-03-8].
»Lactitol contains not less than 98.0percent and not more than 101.0percent of C12H24O11,calculated on the anhydrous basis.
Packaging and storage— Preserve in well-closed containers.
Labeling— Label it to indicate whether it is the monohydrate,the dihydrate,or the anhydrous form.
Water,Method Iá921ñ— between 4.5%and 5.5%(monohydrate);between 9.5%and 10.5%(dihydrate);and not more than 0.5%for the anhydrous form.
Residue on ignition á281ñ: not more than 0.5%.
Heavy metals á231ñ— Dissolve 4g of it in 25mLof water:the limit is 5µg per g.
Reducing sugars— Dissolve 500mg of it in 2.0mLof water in a 10-mLconical flask.Into a similar flask,pipet 2mLof a dextrose solution containing 0.5mg per mL.Concomitantly add 1mLof alkaline cupric tartrate TSto each solution,heat to boiling,and cool:the lactitol solution shows no more turbidity than that produced in the dextrose solution,in which a reddish brown precipitate forms (0.2%,as dextrose).
Related compounds—
Standard solution— Dissolve an accurately weighed quantity of USP Lactitol RSin water to obtain a solution having a known concentration of about 0.3mg per mL.
Chromatographic system— Proceed as directed in the Assay,except to chromatograph the Standard solutioninstead of the Standard preparation.
Test solution— Use the Assay preparation,prepared as directed in the Assay.
Procedure— Separately inject equal volumes (about 25µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the peak responses.The relative retention times are about 0.53for lactose,0.58for glucose,0.67for galactose,0.72for lactulitol,1.0for lactitol,1.55for galactitol,and 1.68for sorbitol.Calculate the percentages of galactitol,sorbitol,lactulitol,lactose,glucose,and galactose in the portion of Lactitol taken by the formula:
1000(C/W)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Lactitol RSin the Standard solution;Wis the weight,in mg,of Lactitol in the Test solution;rUis the peak response of the relevant related compound,if observed,obtained from the Test solution;and rSis the lactitol peak response obtained from the Standard solution.The total of the percentages of all related compounds is not more than 1.5%.
Assay—
Mobile phase— Use water.
Standard preparation— Dissolve an accurately weighed quantity of USP Lactitol RSin water to obtain a solution having a known concentration of about 10.0mg per mL.
Assay preparation— Transfer about 1000mg of Lactitol,accurately weighed,to a 100-mLvolumetric flask,dissolve in and dilute with water to volume,and mix.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a refractive index detector and a 7.8-mm ×30-cm column that contains packing L34.The column is maintained at 85,and the flow rate is about 0.7mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the relative standard deviation for replicate injections is not more than 1.0%for lactitol.
Procedure— Separately inject equal volumes (about 25µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the peak responses.Calculate the quantity,in mg,of C12H24O11in the portion of Lactitol taken by the formula:
100C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Lactitol RSin the Standard preparation,and rUand rSare the lactitol peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 3023
Phone Number:1-301-816-8251