(C9H19N)2·C6H10O8 492.65

Isometheptene,galactarate (2:1)(salt).
6-Methylamino-2-methylheptene,tetrahydroxyadipic acid (2:1)(salt) [7492-31-1].

Packaging and storage— Preserve in well-closed containers.

USP Reference standards á11ñ— USP Isometheptene Mucate RS.

Identification,Infrared Absorption á197Kñ.

pHá791ñ: between 6.0and 7.5,in a solution (1in 20).

Loss on drying á731ñ— Dry it at 60for 18hours:it loses not more than 1.0%of its weight.

Residue on ignition á281ñ: not more than 0.1%.

Assay— Transfer about 500mg of Isometheptene Mucate,accurately weighed,to a 125-mLconical flask.Add 25mLof water,and swirl to dissolve.Add 45.0mLof 0.1Nbromine VS,attach a 30-mLseparator to the conical flask,and evacuate the system.Stir with a magnetic stirrer for 1hour.Equilibrate the system to atmospheric pressure.Add 5mLof hydrochloric acid to the separator,and allow 4mLof it to enter the conical flask.Add 10mLof potassium iodide TSto the separator,and allow the contents to pass into the conical flask.Immediately titrate the liberated iodine with 0.1Nsodium thiosulfate VS,adding 3mLof starch TSas the endpoint is approached.Perform a blank titration (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.1Nsodium thiosulfate is equivalent to 12.32mg of (C9H19N)2·C6H10O8.

Expert Committee:(PA3)Pharmaceutical Analysis 3

USP28–NF23Page 1073

Phone Number:1-301-816-8330