Sulfadimethoxine Soluble Powder
»Sulfadimethoxine Soluble Powder contains Sulfadimethoxine Sodium equivalent to not less than 90.0percent and not more than 110.0percent of the labeled amount of sulfadimethoxine (C12H14N4O4S).
Packaging and storage— Preserve in tight,light-resistant containers,and store at controlled room temperature.
Labeling— Label it to indicate that it is for veterinary use only.
Identification— Shake a quantity equivalent to about 1g with 5mLof diluted hydrochloric acid and 10mLof water.Filter,and to the filtrate add 2.5Nsodium hydroxide dropwise until a precipitate forms and redissolves.Add diluted hydrochloric acid dropwise until a precipitate forms.Collect the precipitate on a very fine filter,and wash it with water and with ether:the sulfadimethoxine so obtained meets the requirements for the Identificationtests under Sulfadimethoxine.
Minimum fill á755ñ: meets the requirements.
pHá791ñ: between 7.0and 8.0,in a solution (1in 20).
Assay—
Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Sulfadimethoxine.
Assay preparation— Transfer an accurately weighed portion of Powder,equivalent to about 50mg of sulfadimethoxine,to a 250-mLvolumetric flask,add about 200mLof Mobile phase,and swirl to dissolve.Dilute with Mobile phaseto volume,and mix.Protect this solution from light.
Procedure— Proceed as directed in the Assayunder Sulfadimethoxine.Calculate the quantity,in mg,of sulfadimethoxine (C12H14N4O4S)in the portion of Powder taken by the formula:
250C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Sulfadimethoxine RSin the Standard preparation;and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist
Expert Committee:(VET)Veterinary Drugs
USP28–NF23Page 1823
Pharmacopeial Forum:Volume No.27(2)Page 2198
Phone Number:1-301-816-8178