Carisoprodol
;)
(±)-2-Methyl-2-propyl-1,3-propanediol carbamate isopropylcarbamate [78-44-4].
»Carisoprodol contains not less than 98.0percent and not more than 102.0percent of C12H24N2O4,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers.
Identification—
A:
Infrared Absorption á197Kñ.
B:
The RFvalue of the principal spot due to carisoprodol in the chromatogram of the test solution obtained in the test for Limit of meprobamatecorresponds to that obtained in a similarly prepared chromatogram of a Standard solution of USP Carisoprodol RSin chloroform containing 100mg per mL.
Loss on drying á731ñ—
Dry it in vacuum at 60
for 3hours:it loses not more than 0.5%of its weight.
for 3hours:it loses not more than 0.5%of its weight.
Heavy metals,Method IIá231ñ:
0.001%.
Limit of meprobamate—
Dissolve 100mg of Carisoprodol in 1.0mLof chloroform.Dissolve USP Meprobamate RSin chloroform to obtain a Standard solution containing about 1mg per mL.Apply a 10-µLportion of the test solution and a separate 5-µLportion of the Standard solution to a suitable thin-layer chromatographic plate (see Chromatography á621ñ),coated with a 0.25-mm layer of chromatographic silica gel.Allow the spots to dry in a current of air,and develop the chromatogram in a solvent system consisting of a mixture of chloroform and acetone (4:1)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the developing chamber,mark the solvent front,allow the solvent to evaporate,and spray the plate alternately with antimony trichloride TSand a 3in 100solution of furfural in chloroform until one or more black spots appear,heat the plate at 110for 15minutes,and examine the plate:any spot in the chromatogram of the test solution having an RFvalue corresponding to that of meprobamate in the chromatogram of the Standard solution is not darker in color than the meprobamate spot in the chromatogram of the Standard solution (0.5%).
for 15minutes,and examine the plate:any spot in the chromatogram of the test solution having an RFvalue corresponding to that of meprobamate in the chromatogram of the Standard solution is not darker in color than the meprobamate spot in the chromatogram of the Standard solution (0.5%).
Organic volatile impurities,Method Vá467ñ:
meets the requirements.
Solvent—
Use dimethyl sulfoxide.
Assay—
Sodium methoxide titrant—
Prepare and standardize as directed for 0.1Nsodium methoxide (in toluene)(see Volumetric Solutionsunder Reagents,Indicators,and Solutions),except to use 200mLof methanol to dissolve the sodium metal,to add 750mLof toluene,and to dilute with methanol to 1000mL.
Procedure—
Transfer about 400mg of Carisoprodol,accurately weighed,to a suitable boiling flask,add 10mLof pyridine,and mix.Add 1drop of phenolphthalein TS,and titrate with Sodium methoxide titrantto a permanent pink endpoint.Add 25.0mLof Sodium methoxide titrant,connect the flask to a water-cooled condenser,and reflux on a hot plate for 30minutes.Allow to cool,add 40mLof alcohol and 7drops of phenolphthalein TS,and titrate the excess alkali with 0.1Nhydrochloric acid VSuntil the pink color disappears.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).Each mLof Sodium methoxide titrantis equivalent to 26.03mg of C12H24N2O4.
Auxiliary Information—
Staff Liaison:Ravi Ravichandran,Ph.D.,Senior Scientist
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 359
Phone Number:1-301-816-8330