Dihydrostreptomycin Sulfate
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Dihydrostreptomycin sulfate (2:3)(salt) [5490-27-7].
»Dihydrostreptomycin Sulfate has a potency equivalent to not less than 650µg of dihydrostreptomycin (C21H41N7O12)per mg,except that if it is labeled as being crystalline,it has a potency equivalent to not less than 725µg of dihydrostreptomycin per mg,or if it is labeled as being solely for oral use,it has a potency equivalent to not less than 450µg of dihydrostreptomycin per mg.
Packaging and storage—
Preserve in tight containers.
Labeling—
Label it to indicate that it is intended for veterinary use only.If it is crystalline,it may be so labeled.If it is intended solely for oral use,it is so labeled.Where it is intended for use in preparing injectable dosage forms,the label states that it is sterile or must be subjected to further processing during the preparation of injectable dosage forms.
USP Reference standards á11ñ—
USP Dihydrostreptomycin Sulfate RS.USP Streptomycin Sulfate RS.USP Endotoxin RS.
Identification—
A:
To a solution of 4mg in 2mLof water,add 0.5mLof 1Nhydrochloric acid,and heat in a water bath for 20minutes.Remove the tube from the bath,and add 1.0mLof a 1in 200solution of 1-naphthol in 1Nsodium hydroxide.Heat again for 10minutes,cool briefly in an ice bath,and add water to make 25mL:a red color develops,intensifying during about 10minutes.
B:
Asolution (1in 50)responds to the tests for Sulfate á191ñ.
Crystallinity á695ñ(where labeled as being crystalline):
meets the requirements.
pHá791ñ:
between 4.5and 7.0,in a solution containing 200mg of dihydrostreptomycin per mL,except that if it is labeled as being solely for oral use,the pHis between 3.0and 7.0.
Loss on drying á731ñ—
Dry about 100mg in a capillary-stoppered bottle in vacuum at 60
for 3hours:it loses not more than 5.0%of its weight,except that if it is labeled as being solely for oral use,it loses not more than 14.0%of its weight.
for 3hours:it loses not more than 5.0%of its weight,except that if it is labeled as being solely for oral use,it loses not more than 14.0%of its weight.
Streptomycin—
Ferric chloride stock solution—
Dissolve 5g of ferric chloride in 50mLof 0.1Nhydrochloric acid.
Ferric chloride solution—
Dilute 2.5mLof Ferric chloride stock solutionwith sufficient 0.01Nhydrochloric acid to make 100mL.Use this solution within 1day.
Standard solutions—
Dissolve an accurately weighed quantity of USP Streptomycin Sulfate RSin water to obtain a stock solution containing 1.0mg of streptomycin (C21H39N7O12)per mL.Transfer 1.0,2.0,3.0,4.0,and 5.0mL,respectively,of this stock solution to each of five 25-mLvolumetric flasks.Transfer 9.0,8.0,7.0,6.0,and 5.0mLof water to the flasks,respectively.
Test solution—
Transfer about 800mg of Dihydrostreptomycin Sulfate,accurately weighed,to a 25-mLvolumetric flask,dissolve in and dilute with water to volume,and mix.Transfer 10.0mLof this solution to a second 25-mLvolumetric flask.
Procedure—
To each of the flasks containing the Standard solutionsand the Test solution,and to a seventh 25-mLvolumetric flask containing 10.0mLof water to provide a blank,add 2.0mLof 1Nsodium hydroxide,and heat in a water bath for 10minutes.Cool the flasks in ice water for 3minutes,and to each add 2.0mLof 1.2Nhydrochloric acid and 5.0mLof Ferric chloride solution.Dilute with water to volume,and mix.Concomitantly determine the absorbances of the solutions from the Standard solutionsand the Test solutionat the wavelength of maximum absorbance at about 550nm,with a suitable spectrophotometer,using the blank to set the instrument at zero.Plot the absorbance values of the solutions from the Standard solutionsversus concentration,in µg per mL,of streptomycin,and draw the straight line best fitting the five plotted points.From the graph so obtained,determine the concentration,C,in µg per mL,of streptomycin in the solution from the Test solution.Calculate the percentage of streptomycin in the portion of Dihydrostreptomycin Sulfate taken by the formula:
6250C/WP,
in which Wis the weight,in mg,of Dihydrostreptomycin Sulfate taken,and Pis the potency,in µg of dihydrostreptomycin per mg,of the Dihydrostreptomycin Sulfate taken as determined in the Assay:not more than 3.0%is found,except that if it is labeled as being crystalline,not more than 1.0%is found,or if it is labeled as being solely for oral use,not more than 5.0%is found.
Other requirements—
Where the label states that Dihydrostreptomycin Sulfate is sterile,it meets the requirements for Sterilityand Bacterial endotoxinsunder Dihydrostreptomycin Injection.Where the label states that Dihydrostreptomycin Sulfate must be subjected to further processing during the preparation of injectable dosage forms,it meets the requirements for Bacterial endotoxinsunder Dihydrostreptomycin Injection.
Assay—
Proceed with Dihydrostreptomycin Sulfate as directed for the turbidimetric assay of dihydrostreptomycin under Antibiotics—Microbial Assays á81ñ.
Auxiliary Information—
Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist
Expert Committee:(VET)Veterinary Drugs
USP28–NF23Page 649
Phone Number:1-301-816-8178