Packaging and storage
Preserve in tight containers, preferably at a temperature not exceeding 25
. Containers intended for sale to the public without prescription contain not more than 30 mL of Oral Solution.
Assay for total ether-soluble alkaloids
[NOTEIt is important that the ether used in this assay shall have been shown by test to be free from peroxides within 24 hours prior to use.
] Transfer about 50 mL, accurately measured, of Oral Solution to a liquid-liquid automatic extractor, add water, if necessary, to reduce the viscosity, render the liquid distinctly alkaline with ammonium hydroxide, and extract with ether for at least 4 hours or until the extraction is complete. Use a water bath to boil the ether. Frequently disconnect the extractor from the condenser, and agitate the lower layer by raising and lowering the center tube or by other suitable manipulation. At the conclusion of the extraction period, transfer the ether extract to a separator, and rinse the extraction flask with 2 or more small volumes of ether, adding the rinsings to the separator. Complete the assay as directed in the
Assay for total ether-soluble alkaloids under
Ipecac, beginning with Extract the alkaloids from the ether.
Assay for emetine and cephaeline
Standard preparation, Phosphate buffer, and Citric acid buffer
Prepare as directed in the
Assay for emetine and cephaeline under
Ipecac.
Assay preparation
Pipet 10 mL of water into a 25-mL volumetric flask. With the aid of a 20-mL pipet, add Oral Solution to volume, taking care to prevent contact of the Oral Solution with the neck of the flask above the graduation line. Insert the stopper, and mix.
Chromatographic columns
Pack a pledget of fine glass wool in the base of a chromatographic tube (25-mm × 200-mm test tube to which is fused a 5-cm length of 7-mm tubing) with the aid of a tamping rod having a disk with a diameter about 1 mm less than that of the tube.
To prepare
Column I, transfer 4.0 mL of the
Assay preparation to a 150-mL beaker, add about 1 g of sodium bicarbonate, and mix. Then proceed as directed for
Chromatographic columns in the
Assay for emetine and cephaeline under
Ipecac, beginning with add 6 g of purified siliceous earth, and prepare
Columns II,
III, and
IV as directed therein.
Procedure
Proceed as directed for
Procedure in the
Assay for emetine and cephaeline under
Ipecac.
Calculate the quantity, in mg, of emetine in each 100 mL of Oral Solution taken by the formula:
2.08
C(
A283 A350)
U / (
A283 A350)
S,
in which the parenthetic expressions are the differences in the absorbances of the solution of emetine from the Assay preparation (U) and the Standard preparation (S), respectively, at the wavelengths indicated by the subscripts, and C is as defined in the Procedure.
Calculate the quantity, in mg, of cephaeline in each 100 mL of Oral Solution taken by the formula:
0.971(2.08
C)(
A283 A350)
U / (
A283 A350)
S,
in which 0.971 is the ratio of the molecular weight of cephaeline to that of emetine, the parenthetic expressions are the differences in the absorbances of the solution of cephaeline from the Assay preparation (U) and the Standard preparation (S), respectively, at the wavelengths indicated by the subscripts, and C is as defined in the Procedure.