Isoxsuprine Hydrochloride Injection
» Isoxsuprine Hydrochloride Injection is a sterile solution of Isoxsuprine Hydrochloride in Water for Injection. It contains not less than 95.0 percent and not more than 105.0 percent of the labeled amount of C18H23NO3·HCl.
Packaging and storage Preserve in single-dose or in multiple-dose containers, preferably of Type I glass.
Identification To a 60-mL separator transfer 10 mL of pH 9.0 buffer (prepared by mixing equal volumes of 0.1 M monobasic potassium phosphate and 0.1 N sodium hydroxide and, using a pH meter, adjusting to a pH of 9.0 by adding, as necessary, more of either solution) add 1 mL of Injection, and mix. Add 2 mL of chloroform, shake vigorously for 1 minute, filter the chloroform extract through a pledget of cotton, and mix the filtrate with 500 mg of potassium bromide. Evaporate the chloroform, carefully removing the last trace of solvent in a small vacuum flask: the IR absorption spectrum of a potassium bromide dispersion of the isoxsuprine so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Isoxsuprine Hydrochloride RS that has been treated in the same manner.
Bacterial endotoxins 85 It contains not more than 35.70 USP Endotoxin Units per mg of isoxsuprine hydrochloride.
pH 791: between 4.9 and 6.0.
Other requirements It meets the requirements under Injections 1.
pH 4.0 Citrate buffer Mix equal volumes of 0.5 M citric acid and 0.5 M sodium citrate, and adjust, by the addition of either solution as necessary, the pH of the solution to 4.0 ± 0.2.
Mixed solvent Shake 40 mL of ether, 160 mL of isooctane, and 10 mL of water in a separator, remove and discard the water phase, and pass the solvent phase through a large pledget of cotton to remove excess water.
Standard preparation Transfer about 40 mg of USP Isoxsuprine Hydrochloride RS, accurately weighed, to a 50-mL volumetric flask, add 2 N sulfuric acid to volume, and mix. Transfer 10.0 mL of this solution to a 100-mL volumetric flask, dilute with 2 N sulfuric acid to volume, and mix. The concentration of USP Isoxsuprine Hydrochloride RS in the Standard preparation is about 80 µg per mL.
Chromatographic column Proceed as directed under Column Partition Chromatography (see Chromatography 621), packing a chromatographic tube with two segments of packing material. The lower segment is a mixture of 2 g of Solid Support and 1 mL of pH 4.0 Citrate buffer, and the upper segment is a mixture prepared as directed under Assay preparation.
Assay preparation Transfer an accurately measured volume of Injection, equivalent to about 4 mg of isoxsuprine hydrochloride, to a 100-mL beaker, add 1 mL of dimethyl sulfoxide, and allow to stand for about 10 minutes, with occasional swirling. Add 1 mL of pH 4.0 Citrate buffer and 3 g of Solid Support, mix as directed under Chromatographic column, and transfer to the column. Pass 75 mL of Mixed solvent through the column, and discard the eluate. Elute the column with a solution prepared by mixing 0.2 mL of bis(2-ethylhexyl)phosphoric acid with 75 mL of Mixed solvent, and collect the eluate in a 125-mL separator. Extract the eluate with two 20-mL portions of 2 N sulfuric acid. Transfer the extracts to a 50-mL volumetric flask, dilute with 2 N sulfuric acid to volume, and mix.
Procedure Concomitantly determine the absorbances of the Assay preparation and the Standard preparation in 1-cm cells at the wavelength of maximum absorbance at about 275 nm, with a suitable spectrophotometer, using a column blank, prepared with Mixed solvent, to set the instrument. Calculate the quantity, in mg, of C18H23NO3·HCl in the portion of Injection taken by the formula:
0.05C(AU / AS)in which C is the concentration, in µg per mL, of USP Isoxsuprine Hydrochloride RS in the Standard preparation; and AU and AS are the absorbances of the Assay preparation and the Standard preparation, respectively.
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USP32NF27 Page 2724