In the chromatogram obtained from the Assay preparation
in the Assay
, the sum of the responses of any peaks detected, other than the peak due to tubocurarine, is not more than 5.0% of the total of all peak responses.
Dissolve about 300 mg, accurately weighed, in 5 mL of water, warming slightly to effect solution. Add 5 mL of glacial acetic acid and 50 mL of methanol, and cool to room temperature. Add 1 drop of eosin Y TS
, and titrate with 0.1 N silver nitrate VS. Each mL of 0.1 N silver nitrate is equivalent to 3.545 mg of Cl. Not less than 9.9% and not more than 10.7% of Cl is found, calculated on the anhydrous basis.
Mix 3 volumes of acetonitrile and 2 volumes of methanol, and allow the mixture to attain room temperature. To 270 mL of this solution in a 1-liter graduated cylinder add 20.0 mL of 25% tetramethylammonium hydroxide solution in methanol, and add water to make 1 L. Adjust with phosphoric acid to a pH of 4.0, filter, and degas.
Dissolve an accurately weighed quantity of USP Tubocurarine Chloride RS
in Mobile phase
to obtain a solution having a known concentration of about 0.3 mg per mL.
Transfer 30 mg of Tubocurarine Chloride, accurately weighed, to a 100-mL volumetric flask. Dissolve in Mobile phase, dilute with Mobile phase to volume, and mix.
System suitability preparation
Dissolve suitable quantities of tubocurarine chloride and phenol in Mobile phase to obtain a solution containing about 0.30 mg and 0.50 mg per mL, respectively.
(see Chromatography 621
)The liquid chromatograph is equipped with a 220-nm detector, and a 4-mm × 25-cm column that contains packing L1. The flow rate is about 1 mL per minute. Chromatograph the System suitability preparation
, and record the peak responses as directed for Procedure:
the resolution, R,
between the two major peaks is not less than 2.0, and the tailing factor, T
, for tubocurarine chloride is not more than 2.0. The relative standard deviation for replicate injections of the Standard preparation
is not more than 2.0%. The relative retention times are about 0.50 and 1.0 for tubocurarine chloride and phenol, respectively.
Separately inject equal volumes (about 10 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 mg, of C37
·HCl in the portion of Tubocurarine Chloride taken by the formula:
100C(rU / rS),
in which C
is the concentration, in mg per mL, of USP Tubocurarine Chloride RS
in the Standard preparation
, and rU
are the peak responses obtained from the Assay preparation
and the Standard preparation