Iron Dextran Injection
»Iron Dextran Injection is a sterile,colloidal solution of ferric hydroxide in complex with partially hydrolyzed Dextran of low molecular weight,in Water for Injection.It contains not less than 95.0percent and not more than 105.0percent of the labeled amount of iron.It may contain not more than 0.5percent of phenol as a preservative.
Packaging and storage— Preserve in single-dose or multiple-dose containers,preferably of Type Ior Type IIglass.
Identification— To 1mLof Injection on a watch glass add 2drops of ammonium hydroxide:no precipitate is formed.Add 2mLof hydrochloric acid,mix,and add 2mLof ammonium hydroxide:a brown precipitate is formed.
Bacterial endotoxins á85ñ— It contains not more than 0.50USP Endotoxin Unit per mg of iron.
Acute toxicity— Select five mice each weighing between 18and 25g,maintained on an adequately balanced diet.Inject a dose of Injection,equivalent to 200mg of iron per kg of body weight,into a tail vein at a rate not exceeding 0.1mLper second.Keep the mice under observation for 48hours after the injection.If none of the mice show outward symptoms of toxicity,the requirements of the test are met.If any of the mice die within the observation period,select four groups of ten mice each weighing between 18and 25g.Inject,intravenously,all mice of one group with one of the following doses of Injection:375,500,750,or 1000mg of iron per kg of body weight.Observe the mice for 7days,and record the number of deaths in each group.If more than 16mice die,calculate the LD50as directed under Design and Analysis of Biological Assays á111ñ:the LD50is not less than 500mg of iron per kg of body weight.
Absorption from injection site— Prepare a site over the semitendinosus muscle of one leg of each of two rabbits by clipping the fur and disinfecting the exposed skin.Inject each site with a dose of 0.4mLper kg of body weight in the following manner.Place the needle in the distal end of the semitendinosus muscle at an angle such as to ensure that the full length of the needle is used,then pass it through the sartorius and vastus medialis muscles.House the rabbits separately.Seven days after the injection,sacrifice the rabbits and dissect the treated legs to examine the muscles:no heavy black deposit of unabsorbed iron compounds is observed,and the tissue is only lightly colored.
pHá791ñ: between 4.5and 7.0.
Nonvolatile residue— Using a “to contain”pipet,transfer 1.0mLonto 3to 5g of sand spread in a shallow layer in a stainless steel dish,the dish and sand having been previously dried and weighed.Rinse the pipet,with several small portions of water,onto the sand.Evaporate on a steam bath to dryness,continue the drying in an oven at 105for 15hours,and weigh:the weight of the residue for Injection labeled to contain 50mg of iron per mLis not less than 28.0%and not more than 32.0%,that for Injection labeled to contain 75mg of iron per mLis not less than 35.0%and not more than 40.0%,and that for Injection labeled to contain 100mg of iron per mLis not less than 37.0%and not more than 43.0%.
Chloride content— Using a “to contain”pipet,transfer 10.0mLof Injection into a 150-mLbeaker,rinsing the pipet into the beaker with several small portions of water.Add 50mLof water and 2mLof nitric acid,mix,and titrate with 0.1Nsilver nitrate VS,determining the endpoint potentiometrically with silver-glass electrodes.Each mLof 0.1Nsilver nitrate consumed is equivalent to 3.545mg of chloride (Cl).The chloride content of Injection labeled to contain 50mg of iron per mLis not less than 0.48%and not more than 0.68%,and that of Injection labeled to contain either 75mg or 100mg of iron per mLis not less than 0.8%and not more than 1.1%.
Limit of phenol— Proceed as directed for Phenolunder Antimicrobial Agents—Content á341ñ:not more than 0.5%is found.
Other requirements— It meets the requirements under Injections á1ñ.
Assay for iron—
Iron stock solution— Transfer an accurately weighed quantity of about 350mg of ferrous ammonium sulfate hexahydrate to a 1000-mLvolumetric flask,add water to dissolve,dilute with water to volume,and mix to obtain a solution having a concentration of 50µg of iron per mL.
Calcium chloride solution— Transfer 2.64g of calcium chloride dihydrate to a 1000-mLvolumetric flask,add 500mLof water,and swirl to dissolve.Add 5.0mLof hydrochloric acid,and dilute with water to volume.
Standard preparations— To separate 100-mLvolumetric flasks transfer 2.0,4.0,6.0,8.0,and 10.0mL,respectively,of Iron stock solution.Dilute each flask with Calcium chloride solutionto volume,and mix to obtain Standard preparationshaving known concentrations of 1.0,2.0,3.0,4.0and 5.0µg of iron per mL.
Assay preparation— Using a “to contain”pipet,transfer an accurately measured volume of Injection,equivalent to about 100mg of iron,to a 200-mLvolumetric flask.Dilute with Calcium chloride solutionto volume,and mix.Pipet 2.0mLof this solution into a 250-mLvolumetric flask,dilute with Calcium chloride solutionto volume,and mix.
Procedure— Concomitantly determine the absorbances of the Standard preparationsand the Assay preparationat the iron emission line of 248.3-nm with a suitable atomic absorption spectrophotometer (see Spectrophotometry and Light-Scattering á851ñ)equipped with an iron hollow-cathode lamp and an air–acetylene flame,using the Calcium chloride solutionas the blank.Plot the absorbance of each Standard preparationversus concentration,in µg per mL,of iron,and draw the straight line best fitting the five plotted points.From the graph so obtained,determine the concentration,in µg per mL,of iron in the Assay preparation.Calculate the quantity,in mg,of iron in each mLof the Injection taken by the formula:
25C/V,
in which Cis the concentration,in µg per mL,of iron in the Assay preparation;and Vis the volume of Injection taken.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 1063
Phone Number:1-301-816-8305