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 30mLof 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 24hours prior to use.
]Transfer about 50mL,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 4hours 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 2or more small volumes of ether,adding the rinsings to the separator.Complete the assay as directed in the
Assay for total ether-soluble alkaloidsunder
Ipecac,beginning with Extract the alkaloids from the ether.
Assay for emetine and cephaeline
Standard preparation,Phosphate buffer,andCitric acid buffer
Prepare as directed in the
Assay for emetine and cephaelineunder
Ipecac.
Assay preparation
Pipet 10mLof water into a 25-mLvolumetric flask.With the aid of a 20-mLpipet,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 1mm less than that of the tube.
To prepare
Column I,transfer 4.0mLof the
Assay preparationto a 150-mLbeaker,add about 1g of sodium bicarbonate,and mix.Then proceed as directed for
Chromatographic columnsin the
Assay for emetine and cephaelineunder
Ipecac,beginning with add 6g of purified siliceous earth,and prepare
Columns II,
III,and
IVas directed therein.
Procedure
Proceed as directed for
Procedurein the
Assay for emetine and cephaelineunder
Ipecac.
Calculate the quantity,in mg,of emetine in each 100mLof Oral Solution taken by the formula:
2.08C(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 Cis as defined in the Procedure.
Calculate the quantity,in mg,of cephaeline in each 100mLof Oral Solution taken by the formula:
0.971(2.08C)(A283-A350)U/(A283-A350)S,
in which 0.971is 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 Cis as defined in the Procedure.