Abstract
The use of derivative and difference-derivative spectrophotometry for the determination of certain drugs in oily injection is presented. The method is illustrated by the determination of oestradiol valerate, oestradiol dipropionate, oestradiol benzoate, testosterone propionate and progesterone in their oily injections. This method is simple, rapid and accurate. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.