G. Cavazzutti

Identification of cosmetic dyes by ion-pair reversed-phase high-performance liquid chromatography

A method based on ion-pair reversed-phase high-performance liquid chromatography with detection at four wavelengths between 400 and 600 nm is reported for the separation and identification of the most common synthetic colour additives in cosmetic products. All the dyes generally employed in the U.S.A. and almost all those in current use in cosmetics in the European Community have been taken into account. The chromatography was performed on a C8 bonded silica packed column, with a 60-min gradient changing from 10 to 95% acetonitrile in water containing 10(-2) M sodium perchlorate (pH 3.0) as mobile phase (flow-rate 2.5 ml/min). Detection limits are in the range 20-100 ng for all dyes investigated. The method has been applied to the analysis of commercial lipsticks.

Determination of preservatives in cosmetic products by reversed-phase high-performance liquid chromatography. II.

We have developed a reversed-phase HPLC method that allows the complete separation of 22 preservatives, including triclosan and triclocarban, with optimization of the mobile phase composition

HPLC determination of rhodamine B (C.I. 45170) in cosmetic products

SummaryA method is proposed for the extraction, separation, identification and quantitative measurement of rhodamine B in cosmetics samples The colour is extracted with a solution of orthophosphoric acid in either water or DMF (depending on the type of cosmetic) adsorbed on a polyamide column, and then eluted with water and methanol. Further clean-up of the extract is performed by means of a Bond Elut C-18 cartridge, from which rhodamine B is eluted with methanol-water (8∶2). The final eluate is examined by HPLC. Chromatography is performed on a C-18 column with a gradient elution from 50∶50 to 70∶30 of acetonitrile-water, containing 0.1 M sodium perchlorate, in 15 min. A diodearray detector enables peak purity analysis. The method gives recovery values of approximately 90%, or better, and the reproducibility is within 4%.

Simultaneous determination of ephedrine and 2-imidazolines in pharmaceutical formulations by reversed-phase HPLC

Abstract A simple, rapid, and accurate method for the determination of naphazoline, oxymetazoline, xylometazoline, and ephedrine in rinological solutions using reversed-phase HPLC was developed. It involves the use of alumina coated with polybutadiene as the stationary phase, acetonitrile-aqueous 10−3 M NaOH (10:90) as the initial mobile phase with a linear gradient from 10 to 80% acetonitrile in 25 min, and detection at 224 nm. The only sample preparation is its dilution with water. Linearity and precision of the method have been assessed. The assay results obtained for various formulations were in agreement with the declared amounts.

HPLC Determination of Ciclopirox, Octopirox, and Pyrithiones in Pharmaceuticals and Antidandruff Preparations

A simple and rapid HPLC method for the determination of ciclopirox, octopirox, and pyrithiones in pharmaceutical or antidandruff formulations has been developed. HPLC was carried out on a Purospher® RP-18 endcapped column using acetonitrile-water containing 0.02 M ortophosphoric acid and 0.5 mM EDTA disodium salt, (68:32, v/v) as the mobile phase and UV detection at 305 or 340 nm. The extraction procedure has been validated analysing samples spiked with known amounts of the active principles. The recoveries were greater than 94% and the reproducibility was within 3%.

Determination of Dequalinium Chloride and Related Impurities in Cosmetics And Pharmaceuticals by Reversed-Phase HPLC

Abstract A rapid, accurate and precise method for the determination of dequalinium chloride and related impurities in pharmaceuticals and cosmetics is described. The method is based on reversed-phase ion-pair HPLC. Different kinds of samples have been considered, but in each case the extracting solvent is methanol-water (1:1, v/v). HPLC is performed on a column packed with Spherisorb ODS-1 (5μm) using acetonitrile-aqueous 0.1 M sodium perchlorate, pH 3.0 (10:90) as initial mobile phase (1.5 mL.min−1), a linear gradient up to 80% acetonitrile in 30 min, and detection at 322 nm. The detection limit is 2 ng for all compounds injected. The method has been applied for the analysis of commercial samples. Author to whom correspondence should be addressed

HPLC Determination of Oxiracetam, Its Impurities, and Piracetam in Pharmaceutical Formulations

Abstract The aim of this work was to develop an high performance liquid chromatographic method for the determination of oxiracetam and its impurities in samples of bulk drugs and pharmaceutical preparations. The only sample preparation necessary for the analysis was its dilution with the mobile phase. Due to the chemical and pharmacological similarity, also the active ingredient piracetam was considered. The method was applied to commercial samples.

Determination of aromatic alcohols in cosmetic products using reversed-phase high-performance liquid chromatography

Dosage de phenoxy-2 ethanol, phenoxy-1 propanol-2, alcool benzylique et alcools dichloro-3,4 et 2,4 benzyliques

HPLC DETERMINATION OF THE SUN-SCREEN AGENT UVINUL T-150 IN COSMETIC PRODUCTS USING DIODE-ARRAY DETECTION

Abstract A method is described for the quantitative determination of the sun-screen agent Uvinul T-150 in cosmetic products. It is based on a simple extraction into acidic THF and a HPLC determination with gradient elution and diode array detection, using a column packed with 5-μm Lichrosorb RP-18. The detection limit is 10 ng and linearity is observed up to 5μg injected. Other sun-screen agents, commonly used in the finished products, have been analyzed and their chromatographic parameters are reported. The method has been applied for determiningOvinu1 T-150 and all the compounds considered in some cosmetic samples of different polarity.

Simultaneous determination of buzepide, phenylpropanolamine, and clocinizine in pharmaceutical preparations by ion-pair reversed-phase HPLC

Abstract A rapid, accurate and precise method for the determination of buzepide, phenylpropanolamine, and clocinizine in a cough-mixture is described. The method is based on reversed-phase ion-pair HPLC. The only sample preparation necessary for the analysis is its dilution with the mobile phase. The resulting solution is analyzed on a column packed with Lichrosorb RP-18 (10μm) with acetonitrile in aqueous 5 10–2M sodium perchlorate, pH 3.0 (15:85) as initial mobile phase (2 mL·min-1) and detection at 220 and 254 nm. Then a linear gradient up to 95% acetonitrile in 20 min, is applied. The detection limits are 500 ng injected for phenylpropanolamine, 40 and 5 ng for buzepide and clocinizine, respectively.