Barbara Starczewska

Simultaneous LC determination of some antidepressants combined with neuroleptics

A reversed-phase HPLC method with UV detection at 252 nm is presented for the simultaneous determination of some tricyclic antidepressants (amitriptyline, imipramine) and neuroleptics (chlorprothixene, thioridazine) in their quaternary mixtures. Sample analysis was performed on a bonded reversed phase C-18, 5 microm, 250 x 4.6 mm ID (Lichrospher 100RP-18) column using acetonitrile and 0.01 M aqueous solution of triethylamine (1:1) as the mobile phase at 0.9 ml/min. The pH was adjusted to 2.7 with concentrated phosphoric acid. The retention time was for imipramine, amitriptyline, chlorprothixene, and thioridazine 5.8, 6.5, 8.3, 10.8 min, respectively. The linearity was obeyed up to 15 ppm for imipramine and amitriptyline, 12 ppm for chlorprothixene and 10 ppm for thioridazine. The presented method also allows the determination of the mentioned drugs individually in their pharmaceutical preparations.

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%.

Application of chrome azurol S for the extractive spectrophotometric determination of fluoxetine and fluvoxamine

Chrome azurol S has been tested as a spectrophotometric reagent for the determination of fluoxetine (FXT) and fluvoxamine (FXM). It reacts in aqueous media with FXT and FXM forming coloured, sparingly soluble in water compounds. These compounds can be quantitatively extracted with some organic solvents. This property has been exploited for the development of the extractive spectrophotometric methods for the determination of fluoxetine and fluvoxamine.

Application of Eriochrome Cyanine R to the Extractive -Spectrophotometric Determination of Chlorpromazine

Abstract Chlorpromazine reacts with Eriochrome Cyanine R forming an ion association compound, insoluble in water but fairly soluble in buthyl alcohol. In this work the optimal reaction and extraction conditions were established. The spectroscopic studies of the formed compound were performed by UV, VIS, IR, 1H NMR and 13C NMR spectrometry. The new extractive-spectrophotometric method for chlorpromazine hydrochloride determination is proposed. Using this method it is possible to determine chlorpromazine hydrochloride concentration in the range 7.0–70 μg/ml. This method was verified against the method of Blazek and applied to determination of chlorpromazine hydrochloride in pharmaceuticals.

Spectrophotometric studies and application of imipramine–eriochrome cyanine R system for determination of imipramine in pharmaceuticals

Eriochrome cyanine R (ECR) has been tested as reagent for the determination of imipramine. It reacts in neutral medium with imipramine forming reddish compound, which can be quantitatively extracted into n-butanol. This property has been successfully used for the extractive-spectrophotometric determination of imipramine. Beers law is obeyed in concentration range of 10-80 microg ml(-1) of imipramine. The method was applied to the determination of imipramine in its pharmaceutical.

SPECTROPHOTOMETRIC DETERMINATION OF FLUVOXAMINE MALEATE AND FLUOXETINE HYDROCHLORIDE

Fluvoxamine maleate and fluoxetine hydrochloride react with eriochrome cyanine R and form pink ion-association compounds. These compounds are insoluble in water, but fairly soluble in organic solvents. Addition of methylcellulose affects the solubility of the compounds and increases the absorbance of the solution. Optimal reaction conditions have been established, and a new spectrophotometric method has been developed for the determination of fluvoxamine and fluoxetine in the concentration ranges 0.6–15 and 0.3–5.0 μg/cm3, respectively.

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.

The use of the new SPE methods for isolation of some tricyclic antidepressant drugs from human serum

Solid-phase extraction (SPE) methods were applied to isolation of amitriptyline (AMI), imipramine (IMI) and chlorprothixene (CPX) from blood human serum. SPE was carried out using the octadecyl (C(18)) column for isolation of AMI and cyclohexyl (CH) columns in the case of IMI and CPX. The spiked serum samples were used to examine the recoveries of these drugs from C(18) and CH sorbent materials. The volume of serum sample was 500 microl. The recoveries of SPE method using CH cartridge were 100.3+/-1.63% (n=7), 99.7+/-2.3% (n=9) for IMI and CPX, respectively. The recovery of AMI from C(18) cartridge was 99.5+/-1.5% (n=8). Finally, after SPE sample clean-up step the antidepressant drugs were assayed by the own extractive-spectrophotometric methods.

Spectrophotometric Determination of Trimipramine Using Cerium(IV) Sulphate(VI) and Potassium Iodate(VII)

Abstract Simple and sensitive methods are proposed for the determination of trimipramine. The methods are based on the oxidation of trimipramine by cerium(IV) sulphate and potassium iodate(VII). The reactions are followed spectrophotometrically by measuring the absorbance of the coloured products at λ = 620 nm and 670 nm, respectively.

Spectrophotometric Determination of Bezafibrate by Ternary Complex Formation with Palladium(II) Chloride and Eosin

Abstract A simple spectrophotometric method for the determination of bezafibrate (BZF) is described. The procedure is based on the ternary complex formation between an investigated drug, palladium(II) ion, and eosin in buffered medium and in the presence of methyl cellulose as a surfactant. The composition of the compound, studied by spectrophotometric methods shows that the molar ratio BZF:Pd(II):eosin is 1:1:1. Optimal conditions for the reaction were established and the procedure was validated. The calibration graph was linear over the range 0.06–0.3 µg mL−1, with relative standard deviation (RSD) 0.3%. The proposed method was successfully applied for the determination of bezafibrate in its pharmaceutical product with mean percentage recoveries of 99.74%.