OXIDATIVE DETERMINATION OF SOME ANTIHISTAMINE DRUGS IN PURE FORM AND THEIR PHARMACEUTICAL PREPARATIONS BY USING PYRIDINIUM FLUORO CHROMATE (PFC) REAGENT

In this paper Chromium (VI) based Pyridinium fluoro chromate (PFC) reagent has been used as an oxidant for the determination of some antihistamine drugs e.g. Promethazine hydrochloride (PMH) and Pheniramine maleate (PM) in pure form and their pharmaceutical preparations such as Phenergan (Injection and tablet) and Avil (Tablet and injection) respectively. The main principle of this method is based on the fact, that each pharmaceutical drug contains a specific organic functional group, which on oxidation in the presence of selected oxidant (Here PFC is used as an oxidant) provides the new oxidized product. This type of oxidation reaction between the drug molecule and an oxidant establishes a stoichiometric relationship between the drug molecule and an oxidant. This relationship is the basis of quantitative estimation of drugs in pure form and their pharmaceutical preparations. In this research, oxidizing reagent Pyridinium fluoro chromate (PFC) oxidizes the sulfur atom of Promethazine hydrochloride (PMH) to the corresponding sulphoxide, whereas in case of Pheniramine maleate (PM) it oxides one hydroxyl (-OH) group of carboxylic (-COOH) group to corresponding aldehydic (-CHO) group. Thus an oxidant PFC establishes a 1:1 ratio with both Promethazine hydrochloride (PMH) and Pheniramine maleate (PM) drug. Oxidative determination of these drugs was carried out by adopting the iodometric titration (Visual volumetric) method. The applied technique was very simple, convenient, accurate, precise and economical. To examine the accuracy and precision of results various statistical analysis such as percentage error, standard deviation (SD) and coefficient of variation (CV) was also calculated for each sample. The proposed method was validated by recovery analysis, by drug addition method.