Colorimetric determination of non-steroidal estrogen level modifiers

ABSTRACT

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 firs 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 [[lambda][max] 510.5nm] measurable in concentration ranges of 2-9 micro g/ml and 1-7 micro g/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 [lambda][max] 458.5 nm in the concentration ranges of 40-280 micro g/ml and 80-320 micro g/ml for I and 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