Specific determination of testosterone in oily injections

Abstract

Multi-stage extraction from a solution of testosterone oily injection in heptane with 85% ethanol yields a hormone extract in which testosterone can be specifically determined by applying the sulphuric acid-picric acid reaction. A parallel analysis of standard samples, which are dissolved in different oily media, and of identical blank media shows that the oily residues and pharmaceutical adjuvants do not interfere at a wavelength of 640 nm and that the recoveries, calculated by comparison with a standard or directly from the value of E^1%_1cm for the ester concerned, are within the range 98.4–101.6%. The precision, for assays of 25 mg ml^–1 solutions, is ±1%.

Testosterone is also determined with similarly high accuracy in complex injections containing oestradiol or progesterone although these hormones pass quantitatively into the hormone extract.

The possibility of determining both testosterone and either progesterone or oestradiol in the same extract, without further manipulation, constitutes a useful saving in time and labour.