Wieslawa Misiuk

ANALYTICAL STUDY OF THE REACTION OF PHENOTHIAZINES WITH SOME OXIDANTS, METAL IONS, AND ORGANIC SUBSTANCES (REVIEW ARTICLE)

Phenothiazines substituted in the 2 and 10 positions exhibit many valuable analytical properties. They are easily oxidized in acidic medium with a number of oxidants, e.g., K2Cr2O7, NH4VO3, Ce(SO4)2, KBrO3, KIO3, KIO4, NaNO2, H2O2, and chloramine T, with the formation of colored oxidation products. This property enable certain phenothiazines to be used as redox indicators for the determination of Fe(II), Sn(II), U(IV), Mo(V), ascorbic acid, etc. Oxidation reactions of phenothiazines were also used for their determination by spectrophotometric and flow injection methods. Some ions, such as iron, vanadium, iodide, or nitrite have a catalytic effect on the oxidation of phenothiazines. Owing to these properties several catalytic methods for the determination of metals, iodide, and nitrite have been proposed. Phenothiazines react in acidic media with platinum metals, e.g., Pd(II), Ru(III), and Pt(IV), the formation of colored complexes. They also react with thiocyanate anionic complexes of metals, e.g., Co(II), Pd(II), Fe(III), Bi(III), Cr(III), Ti(IV), Nb(V), Mo(V), and U(VI). Some organic substances (e.g., picric acid, flavianic acid, alizarin S, titan yellow, brillant blue, pyrocatechol violet) form with phenothiazines colored ion-association compounds sparingly soluble in water. These complexes are the basis for an extractive spectrophotometic determination of some metals or phenothiazines.

Spectrophotometry assay of imipramine and desipramine using ammonium metavanadate and its application to pharmaceutical preparations

Simple and sensitive method for determination of imipramine and desipramine is reported. The procedure is based on the oxidation of the drugs by ammonium metavanadate. Linear calibration graphs were obtained in the concentration range 0.6-40 microg ml(-1) of imipramine and 0.7-35 microg ml(-1) of desipramine with a relative standard deviation (RSD) less than 0.5%. The method was applied to the determination of the drugs in pharmaceutical preparations and compared favourably with independent official methods.

Spectrophotometric determination of some antidepressant drugs

ABSTRACT Amitriptyline and desipramine hydrochlorides react with niobium (V) thiocyanate complex forming yellow ion-association compounds. These compounds are insoluble in water, but fairly soluble in organic solvents. The formation and extraction conditions of the compounds have been established, and a new spectrophotometric method has been developed for the determination of amitriptyline and desipramine in the concentration range of 1–12 µg/mL and 1–6 µg/mL, respectively.

Study on the Inclusion Interactions of β‐Cyclodextrin and Its Derivative with Clomipramine by Spectroscopy and Its Analytic Application

Abstract The inclusion interactions of β‐cyclodextrin (β‐CD) and its derivative, namely hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) with clomipramine (CLOM) have been investigated. The guest molecule was clomipramine and inclusion complexes were characterized by UV, 1H NMR, 13C NMR, and 2D NMR spectroscopy. The main factors affecting the inclusion interaction were discussed in detail. The inclusion complexation behaviour of cyclodextrins with clomipramine was studied in an aqueous buffer solution of pH 4 and pH 5 at room temperature. According to the continuous variation method (Jobs plot) applied to spectroscopy measurements a 1∶1 stoichiometry has been proposed for the complexes. Based on the significant enhancement of absorption intensity of clomipramine, a sensitive UV spectrophotometric methods with high sensitivity and selectivity were developed for determination of substance in bulk aqueous solution in the presence of β‐CD and HP‐β‐CD. The apparent association constant of the complex was 9.42 · 103 mol−1 L and 9.58 · 103 mol−1 L and the linear range was 17.6–70 µg mL−1 with a correlation coefficient of 0.9997 and a relative standard deviation (R.S.D.) of 0.97% and 1.02% using β‐CD and HP‐β‐CD, respectively. There was no interference from the excipients normally used in tablets and capsules. The proposed methods were successfully applied to the analysis of clomipramine in pharmaceuticals with satisfactory results.

Flow injection spectrophotometric determination of perazine

Abstract The flow injection method, involving spectrophotometric detection, is proposed for the determination of perazine. The procedure is based on the oxidation of perazine by cerium(IV) sulphate(VI). Concentrations with perazine in the range 120–300 ppm have been determined with the relative standard deviation of 1.0%. The presented method was applied to the determination of perazine in pharmaceutical formulations.

Spectroscopic and electrochemical analysis of psychotropic drugs

Psychotropic drugs are an important family of compounds from a medical point of view. Their application in therapy requires methods for the determination in pharmaceutical dosage forms and body fluids. Several methods for their analysis have been reported in the literature. Among the methods, spectrophotometric and electrochemical are very useful for the determination of the drugs. Some of the spectrophotometric methods are based on the formation of the binary and ternary compounds with complexes of metals. The formed compounds are sparingly soluble in water, but quantitatively extracted from aqueous phase into organic solvents and the extracts are intensely colored and stable for a few days. These complexes have been employed in pharmaceutical analysis. The electrochemical procedures are very useful in determination of the psychotropic substances in pharmaceutical preparations.

Spectrophotometric determination of imipramine hydrochloride using ammonium peroxidisulfate and niobium(V) thiocyanate complex

Two methods for the determination of imipramine hydrochloride are presented. One method is based on the oxidation of imipramine using ammonium peroxidisulfate with the formation of colored products. This property is the basis of a new spectrophotometric method for imipramine determination. The second method employs the liability of the imipramine tertiary amine group nitrogen atom to form ion-pair compound with niobium(V) thiocyanate complex. The formed ion associate is insoluble in water but well-soluble in organic solvents. Both reactions were followed spectrophotometrically by measuring the absorbances at 658 nm (oxidative method) and at 350 nm (extractive method). The methods have been successfully applied to the determination of imipramine in pharmaceutical preparations. The results were compared with those obtained by the official procedure.

The role of assay methods in characterizing the quality of bulk pharmaceuticals

This study presents the role of assay methods in characterizing the quality of bulk substances in pharmaceutical analysis. High-performance liquid chromatography (HPLC) is the most remarkable development and the technique has become very significant in the quality control of bulk drugs and pharmaceutical formulations, even at the pharmacopoeial level. Development of HPLC and other chtromatographic techniques, coupled with mass spectrometry, is also useful in the determination of drugs and their metabolites in biological samples. The role of electrophoretic, spectroscopic, and other methods in pharmaceutical analysis are discussed here. There are separate sections devoted to microscopy techniques that are useful in the pharmaceutical field, as also the regulatory aspects of drug analysis, with emphasis on questions related to validation.

Analytical Application of the Binary and Ternary Complexes of 2,10-Disubstituted Phenothiazines

Abstract Phenothiazines (PT) are an important family of compound from a medical point of view. They are widely used among the tricyclic antidepressants. Their application in therapy requires methods for their determination in pharmaceuticals and body fluids. The extractive-spectrophotometric methods are very useful for these determinations. They are based on the formation of the binary and ternary complexes. Phenothiazines react with some organic substances (e.g., picric acid, alizarin S, bromocresol green, and triphenylmethane dyes) as well as with thiocyanate or halide complexes of metals [e.g., Co(II), Pd(II), Fe(III), Cr(III), Au(III), Ti(IV), Pt(IV), Mo(V), W(V), U(VI)] forming well-defined ion-association compounds. The compounds are sparingly soluble in water but quantitatively extracted from the aqueous phase into organic solvents. The extracts are intensely colored and stable for a few days. These properties are the basis for utilizing the binary and ternary complexes of phenothiazines in chemical and pharmaceutical analysis. This review described the analytical application of these complexes.

Physicochemical and Analytical Properties of the Complexes of Palladium(II) and Diethazine

Abstract The complexes of palladium(II) with diethazine hydrochloride were obtained. Their composition and some physicochemical properties were studied by UV–vis and infrared measurements. Stoichiometries and instability constants of the prepared complexes were established. Structure of the complexes was elucidated on the basis of analytical results.