Pralidoxime Chloride
(pral'' i dox' eem klor' ide).
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172.61Pyridinium, 2-(hydroxyimino)methyl-1-methyl-, chloride.
2-Formyl-1-methylpyridinium chloride oxime
[51-15-0].» Pralidoxime Chloride contains not less than 97.0 percent and not more than 102.0 percent of C7H9ClN2O, calculated on the dried basis.
Packaging and storage—
Preserve in well-closed containers.
Labeling—
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.
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Identification—
B:
A solution (1 in 10) responds to the tests for Chloride 
191
.
191.
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.
Melting range 741:
between 215
and 225, with decomposition.
741:
between 215 and 225, with decomposition.
Loss on drying 731—
Dry it at 105 for 3 hours: it loses not more than 2.0% of its weight.
731—
Dry it at 105 for 3 hours: it loses not more than 2.0% of its weight.
Residue on ignition 281:
not more than 0.5%.
281:
not more than 0.5%.
Heavy metals, Method I 231:
0.002%.
231:
0.002%.
Chloride content—
Dissolve about 300 mg, accurately weighed, in 150 mL of water, add 20 mL of glacial acetic acid and 10 drops of (p-tert-octylphenoxy)nonaethoxyethanol, and titrate with 0.1 N silver nitrate VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N silver nitrate is equivalent to 3.545 mg of Cl. Not less than 20.2% and not more than 20.8%, calculated on the dried basis, is found.
Other requirements—
Where the label states that Pralidoxime Chloride is sterile, it meets the requirements for Sterility Tests 71 and for Bacterial endotoxins under Pralidoxime Chloride for Injection. Where the label states that Pralidoxime Chloride must be subjected to further processing during the preparation of injectable dosage forms, it meets the requirements for Bacterial endotoxins under Pralidoxime Chloride for Injection.
71 and for Bacterial endotoxins under Pralidoxime Chloride for Injection. Where the label states that Pralidoxime Chloride must be subjected to further processing during the preparation of injectable dosage forms, it meets the requirements for Bacterial endotoxins under Pralidoxime Chloride for Injection.
Assay—
Dilute phosphoric acid solution—
Transfer 10 mL of phosphoric acid to a 100-mL volumetric flask containing 50 mL of water, and mix. Dilute with water to volume, and mix.
Tetraethylammonium chloride solution—
Transfer about 170 mg of tetraethylammonium chloride to a 1-liter volumetric flask, add 3.4 mL of Dilute phosphoric acid solution, and add water to dissolve the mixture. Dilute with water to volume, and mix.
Mobile phase—
Prepare a filtered and degassed mixture of acetonitrile and Tetraethylammonium chloride solution (52:48). Make adjustments if necessary (see System Suitability under Chromatography 621).
621).
Standard preparation—
Dissolve a suitable quantity of USP Pralidoxime Chloride RS, accurately weighed, in water to obtain a Standard solution having a known concentration of about 1.25 mg per mL. (Reserve a portion of the Standard solution for the System suitability preparation.) Pipet 2.0 mL of this solution into a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Assay preparation—
Transfer about 62.5 mg of Pralidoxime Chloride, accurately weighed, to a 50-mL volumetric flask, dissolve in water, dilute with water to volume, mix, and filter. Pipet 2.0 mL of this solution into a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix.
System suitability preparation—
Prepare a solution of pyridine-2-aldoxime in water having a concentration of 0.65 mg per mL. Transfer 2.0 mL of this solution to a 100-mL volumetric flask, add 2.0 mL of the Standard solution, dilute with Mobile phase to volume, and mix.
Chromatographic system
(see Chromatography 621)—The liquid chromatograph is equipped with a 270-nm detector and a 3- to 5-mm × 25-cm column containing 5-µm packing L1. The flow rate is about 1.2 mL per minute. Chromatograph the Standard preparation and the System suitability preparation by injecting about 15 µL of these preparations, and record the peak responses as directed for Procedure: the resolution, R, between the pyridine-2-aldoxime and pralidoxime chloride peaks is not less than 4.0; the column efficiency determined from the analyte peak is not less than 4000 theoretical plates; the tailing factor for the analyte peak is not more than 2.5; and the relative standard deviation for replicate injections is not more than 2.0%.
621)—The liquid chromatograph is equipped with a 270-nm detector and a 3- to 5-mm × 25-cm column containing 5-µm packing L1. The flow rate is about 1.2 mL per minute. Chromatograph the Standard preparation and the System suitability preparation by injecting about 15 µL of these preparations, and record the peak responses as directed for Procedure: the resolution, R, between the pyridine-2-aldoxime and pralidoxime chloride peaks is not less than 4.0; the column efficiency determined from the analyte peak is not less than 4000 theoretical plates; the tailing factor for the analyte peak is not more than 2.5; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 15 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. The relative retention times are about 0.6 for pyridine-2-aldoxime and 1.0 for pralidoxime chloride. Calculate the quantity, in mg, of C7H9ClN2O in the portion of Pralidoxime Chloride taken by the formula:
2.5C(rU / rS)
in which C is the concentration, in µg per mL, of USP Pralidoxime Chloride RS in the Standard 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.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Elena Gonikberg, Ph.D.
Principal Scientific Liaison 1-301-816-8251 |
(SM32010) Monographs - Small Molecules 3 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 4383
Pharmacopeial Forum: Volume No. 29(5) Page 1564