Guaifenesin for Injection
»Guaifenesin for Injection contains not less than 90.0percent and not more than 110.0percent of the labeled amount of guaifenesin (C10H14O4).
Packaging and storage—
Preserve in single-dose or in multiple-dose containers,and store at controlled room temperature.
Labeling—
It meets the requirements for Labelingunder Injections á1ñ.Label it to indicate that it is for veterinary use only.The label states that it is intended for injection only by the intravenous route in horses.
Identification,
Infrared Absorption á197Kñ.
Constituted solution—
At the time of use,it meets the requirements for Constituted Solutionsunder Injections á1ñ.
Sterility á71ñ—
It meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product To Be Examined.
Bacterial endotoxins á85ñ—
It contains not more than 0.05Endotoxin Unit per mg of guaifenesin.
Assay—
Standard preparation—
Dissolve an accurately weighed quantity of USP Guaifenesin RSin chloroform to obtain a solution having a known concentration of about 40µg per mL.
Assay preparation—
Constitute a container of Guaifenesin for Injection with a volume of warm (30
to 35)water,accurately measured,corresponding to the volume of solvent specified in the labeling.Transfer an accurately measured volume of the constituted solution,equivalent to about 100mg of guaifenesin,to a 250-mLseparator containing 10mLof a saturated solution of sodium bicarbonate.Extract with four 25-mLportions of chloroform,combining the chloroform extracts in a second 250-mLseparator.Wash the combined chloroform extracts with 5mLof 1Nhydrochloric acid.Filter the washed chloroform extracts through chloroform-moistened filter paper,collecting the filtrate in a 100-mLvolumetric flask.Dilute with chloroform to volume,and mix.Transfer 4.0mLof this solution to a second 100-mLvolumetric flask,dilute with chloroform to volume,and mix.
to 35)water,accurately measured,corresponding to the volume of solvent specified in the labeling.Transfer an accurately measured volume of the constituted solution,equivalent to about 100mg of guaifenesin,to a 250-mLseparator containing 10mLof a saturated solution of sodium bicarbonate.Extract with four 25-mLportions of chloroform,combining the chloroform extracts in a second 250-mLseparator.Wash the combined chloroform extracts with 5mLof 1Nhydrochloric acid.Filter the washed chloroform extracts through chloroform-moistened filter paper,collecting the filtrate in a 100-mLvolumetric flask.Dilute with chloroform to volume,and mix.Transfer 4.0mLof this solution to a second 100-mLvolumetric flask,dilute with chloroform to volume,and mix.
Procedure—
Concomitantly determine the absorbances of the Standard preparationand the Assay preparationat the wavelength of maximum absorbance at about 276nm,using chloroform to zero the instrument.Calculate the quantity,in mg,of guaifenesin (C10H14O4)in each mLof the constituted solution of Guaifenesin for Injection taken by the formula:
2.5(C/V)(AU/AS),
in which Cis the concentration,in µg per mL,of USP Guaifenesin RSin the Standard preparation,Vis the volume,in mL,of constituted solution taken to prepare the Assay preparation,and AUand ASare the absorbances of the Assay preparationand the Standard preparation,respectively.
Auxiliary Information—
Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist
Expert Committee:(VET)Veterinary Drugs
USP28–NF23Page 923
Phone Number:1-301-816-8178