Analytical evaluation of gestogens in oral contraceptives
Oral contraceptive preparations are now manufactured and prescribed on a large scale, and the public analyst has a duty to ensure that a chemically satisfactory product is supplied.
A scheme has been devised that will enable all of the ingredients, both progestogenic and oestrogenic, of the preparations at present available in this country to be identified and assayed.
The active ingredients are separated from the tablet excipients by solvent extraction, the solution is evaporated and the residue identified by using infrared spectrophotometry and thin-layer chromatography. Assay of the ingredients involves the use of ultraviolet spectrophotometry. A few exceptions were found to this general scheme and these have been successfully overcome by suitable modifications.