Ipratropium Bromide
8-Azoniabicyclo[3.2.1]octane-3-(3-hydroxy-1-oxo-2-phenylpropoxy)-8-methyl-8-(1-methylethyl)-, bromide, monohydrate(endo,syn)-, (±)-. (8r)-3-Hydroxy-8-isopropyl-1h,5h-tropanium bromide (±)-tropate monohydrate [66985-17-9]. » Ipratropium Bromide contains not less than 98.0 percent and not more than 102.0 percent of C20H30BrNO3·H2O, calculated on the anhydrous basis.
Packaging and storage
Preserve in tight containers, and store at room temperature.
USP Reference standards 11
USP Ipratropium Bromide RS. USP Ipratropium Bromide Related Compound A RS. USP Ipratropium Bromide Related Compound B RS. USP Ipratropium Bromide Related Compound C RS.
Identification
C:
The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
pH 791:
between 5.0 and 7.0, in a solution (1 in 10).
Water, Method I 921:
between 3.9% and 4.4%.
Residue on ignition 281:
not more than 0.1%.
Heavy metals, Method II 231:
0.001%.
Limit of ipratropium related compound A
Adsorbent
Use a suitable high-performance thin-layer chromatographic silica gel mixture.
Test solution
Dissolve about 100 mg of Ipratropium Bromide, accurately weighed, in 5 mL of methanol.
Stock standard solution
Dissolve an accurately weighed quantity of USP Ipratropium Bromide Related Compound A RS in methanol and dilute quantitatively, and stepwise if necessary, with methanol to obtain a solution having a known concentration of about 0.05 mg per mL.
Standard solutions
In separate flasks, dilute 0.5, 1.0, and 2.0 mL of the Stock standard solution with methanol to 5 mL to obtain a set of standard solutions having known concentrations of approximately 0.005, 0.01, and 0.02 mg of ipratropium bromide per mL. These solutions correspond to 0.025% (Standard solution C), 0.05% (Standard solution B), and 0.1% (Standard solution A), respectively, relative to the Test solution.
Application volume:
1 µL.
Developing solvent system
Prepare a mixture of methylene chloride, dehydrated alcohol, water, and formic acid (18:18:3:1).
Procedure
Proceed as directed for Thin-Layer Chromatography under Chromatography 621. Develop the plate for about 15 minutes, then remove from the tank and dry at 60 for 15 minutes. Spray the plate with the Dragendorff's TS, and allow to dry briefly. Spray the plate with sodium nitrite solution (5 in 100), and immediately cover with a glass plate. The RF for ipratropium bromide related compound A and ipratropium bromide are about 0.15 and 0.36, respectively. Any spot in the chromatogram obtained from the Test solution, except for the principal spot, is not more intense than the spot in the chromatogram obtained from Standard solution A (0.1%).
Related compounds
Phosphate solution, Buffer, Mobile phase, and Chromatographic system
Proceed as directed in the Assay.
System suitability solution
Dissolve suitable quantities of USP Ipratropium Bromide RS and USP Ipratropium Bromide Related Compound B RS in Mobile phase to obtain a solution containing about 0.03 mg per mL and 0.01 mg per mL, respectively.
Standard solution
Dissolve an accurately weighed quantity of USP Ipratropium Bromide RS in Mobile phase and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 0.03 mg per mL.
Test solution
Transfer about 250 mg of Ipratropium Bromide, accurately weighed, to a 25-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)
Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are listed in the accompanying table; the resolution, R, between ipratropium and ipratropium related compound B is not less than 4; the tailing factor of the ipratropium peak is not more than 2.5; and the relative standard deviation for replicate injections is not more than 5%.
Procedure
Separately inject equal volumes (about 5 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of related compounds in the portion of Ipratropium Bromide taken by the formula:
100(1/F)(CS / CT)(ri / rS)
in which F is the relative response factor of the related compound relative to ipratropium bromide; CS is the concentration, in mg per mL, of USP Ipratropium Bromide RS in the Standard solution; CT is the concentration, in mg per mL, of Ipratropium Bromide in the Test solution; ri is the individual peak response of the individual related compound; and rS is the peak response of ipratropium in the Standard solution. See the accompanying table for relative retention times, relative response factors, and acceptance criteria.
Assay
Phosphate solution
Transfer 8.9 g of dibasic sodium phosphate dihydrate to a 100-mL volumetric flask. Dissolve in and dilute with water to volume, and mix.
Buffer
Transfer 14.3 g of monobasic sodium phosphate dihydrate and 2.0 g of tetrapropylammonium chloride to a 1-L volumetric flask, dissolve in and dilute with water to volume, and mix. Adjust with Phosphate solution to a pH of 5.5 ± 0.2. Pass through a nylon membrane filter having a porosity of 0.45 µm or finer.
Mobile phase
Prepare a filtered and degassed mixture of Buffer and methanol (87:13). [noteDo not use the Mobile phase after 36 hours.] Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution
Dissolve suitable quantities of USP Ipratropium Bromide RS and USP Ipratropium Related Compound C RS in Mobile phase and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 0.5 mg per mL and 0.1 mg per mL, respectively.
Standard preparation
Dissolve an accurately weighed quantity of USP Ipratropium Bromide RS in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 0.5 mg per mL.
Assay preparation
Transfer about 50 mg of Ipratropium Bromide, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 220-nm detector and 3.9-mm × 15-cm column that contains 4-µm packing L1. The flow rate is about 1.5 mL per minute. The column temperature is maintained at 30. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.7 for ipratropium related compound C and 1.0 for ipratropium bromide; the resolution, R, between ipratropium related compound C and ipratropium is not less than 4; the tailing factor of the ipratropium peak is not more than 2.5; and the relative standard deviation for replicate injections is not more than 1%.
Procedure
Separately inject equal volumes (about 5 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in percent, of C20 H30BrNO3·H2O in the portion of Ipratropium Bromide taken by the formula:
100(CS / CT)(rU / rS)
in which CS is the concentration, in mg per mL, of USP Ipratropium Bromide RS in the Standard preparation; CT is the concentration, in mg per mL, of Ipratropium Bromide in the Assay preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
Chromatographic Column
USP32NF27 Page 2685
Pharmacopeial Forum: Volume No. 33(2) Page 241
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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