Helena Puzanowska-Tarasiewicz

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.

Investigation and analytical application of the reactions of eriochrome cyanine R with fluvoxamine and fluoxetine.

Eriochrome cyanine R (ECR) reacts with fluvoxamine (FXM) and fluoxetine (FXT) forming coloured ion-association compounds. The composition of the compounds, studied by spectrophometric methods showed that the molar ratio ECR:FXM = 1:2 and ECR:FXT = 1:2. The formation and extraction conditions of the compounds were established. The compounds were characterised by UV, VIS, and IR spectrometry. It was found that the compounds are insoluble in water but quantitatively extracted into buthanol. Under the optimal experimental conditions fluvoxamine and fluoxetine were determined in the range 2-40 microg/ml and 2-20 microg/ml, respectively. The relative standard deviation is about +/- 2%.

Extractive-spectrophotometric determination of some phenothiazines with dipicrylamine and picric acid

Dipicrylamine and picric acid have been tested as reagents for the determination of promethazine and perphenazine. They react in neutral media with these drugs forming the coloured compounds. The compounds are sparingly soluble in water and quantitatively extracted into organic solvents. The extracts are intensely coloured and very stable. These properties have been exploited for the extractive spectrophotometric determination of promethazine and perphenazine in pure solutions and pharmaceuticals. Linear calibration graphs were obtained in the concentration range 4-40, 3-30 microg ml(-1) of promethazine and 4-80, 8-60 microg ml(-1) of perphenazine for picric acid and dipicrylamine, respectively. The relative standard deviation (RSD) is less than 0.8%.

Electrooxidation of Some Antifungal Agents and Their Square-Wave Voltammetric Determination in Cosmetics and Pharmaceutics

Ketoconazole and methylparaben were electrochemically studied using cyclic and square wave voltammetric (SWV) techniques at glassy carbon electrode. The oxidation of methylparaben and ketoconazole—the mechanism under scrutiny in this study—was characterized by irreversibility and the features of a pH-dependent diffusion controlled process. Optimal conditions for the electrochemical behavior of methylparaben and ketoconazole were investigated [e.g., potential window, supporting electrolyte and potential scan rates, the dependence of current intensities and potentials on pH, the linear relationship between the peak current and the concentration, limit of detection (LOD), limit of quantification (LOQ), recovery, and accuracy]. The proposed procedures were used for the determination of studied substances in cosmetic and pharmaceutical samples for methylparaben and ketoconazole, respectively. The current-concentration plot for methylparaben was linear over the range from 1 · 10−5 to 2.02 · 10−4 mol L−1 in 0.1 mol L−1 HClO4. The linear response for ketoconazole was obtained in the range of 3.2 · 10−7–9.58 · 10−6 mol L−1 in NH3-NH4Cl buffer at pH 9. The repeatability and reproducibility of the methods for the studied substances were also determined. Furthermore, results obtained by the proposed methods have been compared with high-performance liquid chromatographic methods.

Electrochemical Oxidation of Phenothiazine Derivatives at Glassy Carbon Electrodes and Their Differential Pulse and Square‐wave Voltammetric Determination in Pharmaceuticals

Abstract Three 2,10‐disubstituted phenothiazines—chlorpromazine hydrochloride (CPM), thioridazine hydrochloride (TR) and propericiazine (PRC)—were electrochemically studied in various buffer systems at different pH values, using a glassy carbon electrode. The substances were electrochemically oxidized at potential range 0.55–0.75 V. The oxidation was reversible and exhibited diffusion‐controlled process. The mechanism of the oxidation process is discussed. According to the linear relation between peak current and concentration, differential pulse voltammetry (DPV) and square wave voltammetry (SWV) methods for quantitative determination of chlorpromazine and propericiazine in 0.1 M HClO4, and thioridazine in pH 2 phosphate buffer, was applied. Both the repeatability and reproducibility of the methods were also determined for all studied substances. The developed procedures were successfully applied to the determination of chlorpromazine and thioridazine in pharmaceutical dosage forms.

Application of reinecke salt and alizarin S for the determination of promazine.

Reinecke salt and alizarin S have been tested as reagents for the determination of promazine. They react in neutral and acidic media with promazine forming a reddish and brown crystalline compounds. The compounds are sparingly soluble in water but fairly soluble in acetone and methanol. The quantitative extraction of compound of promazine with alizarin S has been used for the extractive spectrophotometric determination of promazine. Formation of promazine ion-association complex with Reinecke salt has been applied for indirect determination of low concentrations of promazine by AAS measurement of the chromium content of the reineckate counter - anion.

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.

Analytical Applications of Reactions of Iron(III) and Hexacyanoferrate(III) with 2,10-Disubstituted Phenothiazines

The presented review is devoted to analytical applications of reactions of Fe(III) and K3[Fe(CN)6] with 2,10-disubstituted phenothiazines (PT). It was found that iron(III) and hexacyanoferrate(III) ions in acidic media easily oxidized PT with the formation of colored oxidation products. This property has been exploited for spectrophotometric determination of iron(III) ions and phenothiazines. Some flow-injection procedures of the determination of PT based on the oxidation reaction by means of the above-mentioned oxidants have been proposed. In the presented review, the application of 2,10-disubstituted phenothiazines as indicators in complexometric titration of iron(III) as well as procedures of PT determination based on generation of ternary compound in the system Fe(III)-SCN−- PT was also described.

Solid Phase Extraction of Olanzapine with Reverse Phase Sorbents Prior to UV and HPLC Analysis

Abstract A solid‐phase extraction (SPE) method for the sample clean‐up followed by a UV and reversed‐phase high performance liquid chromatography (HPLC) procedure for the assay of olanzapine (OLA) is reported. SPE was carried out using the octadecyl (C18), cyclohexyl (C6H11) columns, which belong to the reverse phase sorbents and the SDB‐1 column, define as polymeric sorbent. The spiked albumin samples were used to examine the recoveries of olanzapine from the investigated sorbent materials. The volume of albumin samples was 500 µl. The best extraction recoveries were performed with C18 cartridges and these varied between 99.0–100.5% and 98.5–104.0% prior to our UV and literature HPLC analysis, respectively.

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.