Collaborative Study of an Assay for Progestational Steroids in Individual Contraceptive Tablets

A single tablet assay method has been developed for determining norethindrone, norethynodrel, and norgestrel in commercial contraceptive tablets. The steroid is separated from the tablet constituents on a diatomaceous earth column, the chloroform eluate is reacted with isonicotinic acid hydrazide, and the steroid is determined by colorimetry. Norethynodrel is isomerized to a conjugated ketosteroid before the colorimetric determination. Fourteen laboratories collaboratively tested the method. The average recoveries in 3 brands of tablets were as follows: 102.6% for the sample labeled as containing 0.35 mg norethindrone/tablet, 99.4% for the 2.5 mg norethynodrel/tablet, and 98.2% for the 0.5 mg norgestrel/tablet. The assay method has been adopted as official first action.

Determination of Dihydrocodeinone in Mixtures With Antihistamines

Dihydrocodeinone is separated from pheniramine and similar antihistamines by passage of a chloroform extract of the combined bases over a chromatographic column on which 2N HCl is the stationary phase. The latter is retained on the column while the dihydrocodeinone passes through. The dihydrocodeinone is transferred from the chloroform eluate by shaking it with a measured volume of sulfuric acid, and the concentration is measured spectrophotometrically. The method is recommended for adoption as official, first action.