Hanan Merey
Prof. of Analytical Chemistry, Faculty of Pharmacy, Cairo University
Two simple, accurate and precise methods are described for the determination of some non-steroidal estrogen level modifiers in pure powder form and pharmaceutical dosage forms. The first method is based on the reduction of ferric phenanthrolene (ferriin) to ferroin by Tamoxifen citrate (I) or Clomiphene citrate (II). The obtained ferroin chelate has an orange red color ( λmax 510.5 nm) measurable in concentration ranges of 2-9 µg/ml and 1-7 µg/ml for I and II, respectively. The second method is based on charge-transfer complexation between 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) as electron acceptor and (I) or Raloxifene hydrochloride (III) as the electron donors. The produced red color can be measured at λmax 458.5 nm in the concentration ranges of 40-280 µg/ml and 80-320 µg/ml for I & III, in orders. Different factors affecting the color formation have been studied and optimized and the proposed methods were successfully applied for the determination of the named drugs in their pharmaceutical formulations.