ANALSCI : Vol. 16 (2000) , No. 11 p.1127

A Simple Spectrophotometric Determination of Some Phenothiazine Drugs in Pharmaceutical Samples

Padmarajaiah NAGARAJA¹⁾, Nandipura D. DINESH¹⁾, Netkal M. MADE GOWDA²⁾ and Kanchugarakoppal S. RANGAPPA¹⁾

1) Department of Chemistry, University of Mysore
2) Department of Chemistry, Western Illinois University

(Received July 13, 2000)
(Accepted September 13, 2000)

A new, simple and sensitive spectrophotometric method for the determination of some phenothiazine drugs has been developed. The proposed method is based on the reaction of promethazine hydrochloride (PH), chlorpromazine hydrochloride (CPH), triflupromazine hydrochloride (TPH), fluphenazine hydrochloride (FPH), trifluoperazine hydrochloride (TFPH), perazine dimaleate (PDM) and prochlorperazine maleate (PCPM) with iron(III) and a subsequent reaction with ferricyanide in an acetic acid medium to yield Prussian blue colored product with a maximum absorption at 700-720 nm. The common excipients used as additives in pharmaceuticals do not interfere with the proposed method. Analytical data for determination of the pure compound are presented together with the applications of the proposed method to the analysis of some pharmaceutical formulations. The results compare favorably with those of the official method.