Identification—
A:
To a quantity of powdered Tablets, equivalent to about 75 mg of mecamylamine hydrochloride, add 50 mL of chloroform, and triturate the mixture for 5 minutes. Filter, and evaporate the filtrate on a steam bath with the aid of a current of air to dryness: the IR absorption spectrum of a potassium bromide dispersion of a portion of the residue so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of
USP Mecamylamine Hydrochloride RS.
B:
A portion of the residue obtained in
Identification test
A responds to the tests for
Chloride 
191
.
Dissolution 711—
Medium:
water; 750 mL.
Apparatus 2:
50 rpm.
Time:
30 minutes.
Determine the amount of C11H21N·HCl dissolved using the following procedure.
Diluent—
Prepare a solution of triethylamine in alcohol (1:100).
Internal standard solution—
Prepare a solution of biphenyl in Diluent having a concentration of 82.5 µg per mL.
Test solution—
[NOTE—Condition the solid-phase extraction column specified in this procedure in the following manner. Wash the column with 5 mL of water, then with 5 mL of Diluent, and finally with two 5-mL portions of water.] Transfer by pipetting 25.0 mL of the solution under test through a freshly conditioned solid-phase extraction column containing L1 packing with a sorbent-mass to column volume ratio of 360 mg per 5 mL, or equivalent. Wash the pipet and the solid-phase extraction column with two 5-mL portions of water. Discard the filtrate. Elute the solid-phase extraction column with two 4-mL portions of Diluent, and collect the eluate in a 10-mL volumetric flask containing 1.0 mL of Internal standard solution. Dilute with Diluent to volume, and mix.
Chromatographic system
(see
Chromatography 621)—The gas chromatograph is equipped with a flame-ionization detector, a splitless injection system, and a 0.53-mm × 30-m analytical column coated with a 1-5-µm layer of phase G27. The carrier gas is helium at a flow rate of 5.2 mL per minute. The detector and column temperatures are maintained at 250
and 150
, respectively. Chromatograph replicate injections of the
Standard solution, and record the peak responses as directed for
Procedure: the column efficiency is not less than 4000 theoretical plates, the tailing factor is not more than 2, and the relative standard deviation is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 2 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the amount in mg, of C
11H
21N·HCl dissolved by the formula:
0.3C(RU / RS),
in which
C is the concentration, in µg per mL, of
USP Mecamylamine Hydrochloride RS in the
Standard solution; and
RU and
RS are the peak response ratios of the mecamylamine hydrochloride peak to the internal standard peak obtained from the
Test solution and
Standard solution, respectively.
Tolerances—
Not less than 75% (Q) of the labeled amount of C11H21N·HCl is dissolved in 30 minutes.
Assay—
Weigh and finely powder not fewer than 30 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 50 mg of mecamylamine hydrochloride, to a glass-stoppered, 125-mL conical flask. Add about 25 mL of water, insert the stopper in the flask, and shake by mechanical means for 20 minutes. Transfer the contents of the flask to a 250-mL separator with the aid of small portions of water. Add 1 mL of 1 N sodium hydroxide and 5 g of sodium chloride, and extract the mixture successively with two 50-mL and three 25-mL portions of ether. Wash the combined ether extracts with three 10-mL portions of water, and wash, in turn, the combined water washes with a 10-mL portion of ether, adding it to the washed combined ether extracts. Transfer the ether phase to a 250-mL conical flask containing 25.0 mL of 0.02 N sulfuric acid VS, and evaporate the ether on a steam bath. Cool the solution, add
methyl red TS, and titrate the excess acid with 0.02 N sodium hydroxide VS. Each mL of 0.02 N sulfuric acid is equivalent to 4.075 mg of mecamylamine hydrochloride (C
11H
21N·HCl).
