Giuseppe Carlucci

Analysis of fluoroquinolones in biological fluids by high-performance liquid chromatography

High-performance liquid chromatographic methods for the analysis of fluoroquinolones in biological fluids are reviewed. In particular, sample preparation and handling procedures, chromatographic conditions, and detection methods are discussed. A summary of published high-performance liquid chromatographic assays for individual fluoroquinolones is included.

Simultaneous determination of losartan and hydrochlorothiazide in tablets by high-performance liquid chromatography.

A method for the simultaneous determination of losartan potassium and hydrochlorothiazide in tablets is described. The procedure, based on the use of reversed-phase high-performance liquid chromatography, is linear in the concentration range 3.0-7.0 microg ml(-1) for losartan and 0.5-2.0 microg ml(-1) for hydrochlorothiazide, is simple and rapid and allows accurate and precise results. The limit of detection was 0.08 microg ml(-1) for losartan and 0.05 microg ml(-1) for hydrochlorothiazide.

Determination of losartan and hydrochlorothiazide in tablets by CE and CEC.

Capillary Electrophoresis (CE) and Capillary Electrochromatography (CEC) have been used to determine losartan and hydrochlorothiazide. The CE separation was carried out in an uncoated capillary filled with a 100 mM sodium borate pH 9 solution containing trimethyl-beta-cyclodextrins. CEC was performed using a capillary packed with a RP-18 stationary phase. The mobile phase was a mixture of 50 mM ammonium acetate pH 7, water, acetonitrile (1/1.5/7.5). By CE and CEC suitable methods to determine simultaneously losartan and hydrochlorothiazide in working standard mixture or pharmaceutical form were obtained. The proposed methods are very simple and both gave accurate and precise results.

Anti-Inflammatory Properties of Drugs from saffron crocus

The medicinal uses of saffron (Crocus sativus Linnaeus) have a long history beginning in Asian countries since the Late Bronze Age. Recent studies have validated its potential to lower the risk of several diseases. Some metabolites derived from saffron stigmas exert numerous therapeutic effects due to hypolipidemic, antitussive, antioxidant, antidiabetic activities and many others. Water and ethanol extracts of Crocus sativus L. are cardioprotective and counteract neurodegenerative disorders. Many of these medicinal properties of saffron can be attributed to a number of its compounds such as crocetin, crocins and other substances having strong antioxidant and radical scavenger properties against a variety of radical oxygen species and pro-inflammatory cytokines. Botany, worldwide spreading of cultivars, biochemical pathways, active constituents and chemical detection methods are reviewed. Therapeutic uses of saffron principles with particular regard to those exhibiting antioxidant and thus anti-inflammatory features are discussed. To date, very few adverse health effects of saffron have been demonstrated. At high doses (more than 5 g/die day), it should be avoided in pregnancy owing to its uterine stimulation activity.

Simultaneous determination of enalapril maleate and hydrochlorothiazide in tablets by derivative UV spectrophotometry and high-performance liquid chromatography

Abstract A method for the simultaneous determination of enalapril maleate and hydrochlorothiazide in pharmaceutical formulations (tablets) is described. The procedure is based on the use of the high-performance liquid chromatography (HPLC), and of the second-derivative ultraviolet spectra, by utilizing the linear relationship between substances concentration and derivative peak amplitude. The minimum concentration detectable by derivative spectrophotometry was 1 μg ml−1 for both drugs, and by HPLC 50 ng ml−1 for hydrochlorothiazide and 100 ng ml−1 for enalapril maleate. The relative standard deviations observed were approx. 2% for derivative spectrophotometry, and 1.5% for HPLC. The proposed methods, which give thoroughly comparable data, are simple and rapid, and allow precise and accurate results.

Simultaneous determination of valsartan and hydrochlorothiazide in tablets by high-performance liquid chromatography

ABSTRACT A method for the simultaneous determination of valsartan and hydrochlorothiazide in tablets is described. The procedure, based on the use of reversed-phase high-performance liquid chromatography, is linear in the concentration range 5.0-10.0 μg ml−1 for valsartan and 0.5-2.0 μg ml−1 for hydrochlorothiazide, is simple and rapid and allows accurate and precise results. The limit of detection was 1.0 μg ml−1 for valsartan and 0.05 μg ml−1 for hydrochlorothiazide.

Simultaneous determination of 5-aminosalicylic acid, acetyl-5-aminosalicylic acid and 2,5-dihydroxybenzoic acid in endoscopie intestinal biopsy samples in humans by high-performance liquid chromatography with electrochemical detection

A high-performance liquid chromatographic method for the simultaneous determination of 5-aminosalicylic acid (5-ASA), acetyl-5-aminosalicylic acid (Ac-5-ASA) and 2,5-dihydroxybenzoic acid (5-HSA) in human endoscopic intestinal biopsy with electrochemical detection has been developed and validated. A liquid-liquid extraction procedure was used to isolate these drugs from the biological material prior to analysis. The compounds were separated on an Erbasil S reversed-phase column using methanol-critic acid-sodium hydrogenphosphate-heptane-sulfonic acid-disodium ethylenediaminetetraacetate (pH 3) as mobile phase. The method was linear from 1.0 to 300 ng ml-1 for 5-ASA, from 10 to 1000 ng ml-1 for Ac-5ASA and from 0.1 to 10 ng m-1 for 5-HSA. The limit of detection for 5-ASA and for Ac-5-ASA was 1 ng ml-1 and that for 5-HSA was 0.1 ng ml-1. This procedure is suitable for pharmacological and clinical studies of 5-ASA.

Microextraction by packed sorbent and high performance liquid chromatography determination of seven non-steroidal anti-inflammatory drugs in human plasma and urine

This paper reports a new MEPS-HPLC-PDA method for the simultaneous analysis of seven non-steroidal anti-inflammatory drugs (Furprofen, Indoprofen, Ketoprofen, Fenbufen, Flurbiprofen, Indomethacin, and Ibuprofen) in human plasma and urine. NSAIDs were resolved on a Gemini C18 column (4.6 mm × 250 mm; 5 μm particle size) using a gradient elution mode with a run time of 25 min, comprising re-equilibration, without further purification. The method was validated over the concentration range from 0.1 to 10 μg/mL for all the analytes both in human plasma and urine, using Benzyl 4-hydroxybenzoate as the internal standards. This method was successfully tested to NSAIDs analyses in real matrices, in order to check the method potentiality and the correct response. The results from assay validations show that the method is selective, sensitive and robust. The limit of quantification of the method was 0.1 μg/mL for all analytes, and weighted-matrix-matched standard curves showed a good linearity up to 10 μg/mL. In order to check the correct response for over-range samples, parallelism tests were also assessed. In the entire analytical range the intra and inter-day precision (RSD%) values were ≤ 7.31% and ≤ 13.5%, respectively. For all the analytes the intra and inter-day trueness (Bias%) values ranged from -11.3% to 10.2%. To our knowledge, this is the first MEPS-HPLC-PDA based method that uses MEPS procedure for simultaneous determination of these seven NSAIDs in plasma and urine samples.

Anthraquinone profile, antioxidant and antimicrobial activity of bark extracts of Rhamnus alaternus, R. fallax, R. intermedia and R. pumila

The quantity of phenols, as well as antioxidant and antimicrobial activities, were investigated in bark of Rhamnus alaternus L., R. fallax Boiss., R. intermedia Steud. et Hochst., and R. pumila Turra from natural stands in Croatia. The most abundant anthraquinones in the investigated extracts were chrysophanol in R. alaternus (3.14 mg/g), emodin in R. pumila (0.339 mg/g), and physcion in R. fallax (2.70 mg/g) and R. intermedia (0.285 mg/g). The species exhibiting the highest antioxidant activity were R. fallax and R. pumila. A positive correlation was observed between total phenolic and flavonoid levels of the extracts and antioxidant activity in some of the assays. All species showed antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Aspergillus niger and Microsporum gypseum with minimal inhibitory concentrations equal to or below 2.500 mg/mL. The results indicate that the investigated Rhamnus species are a source of anthraquinones and other phenols, which act as multifunctional antioxidants with antimicrobial activity.

Development and application of high-performance liquid chromatography for the study of two new oxyprenylated anthraquinones produced by Rhamnus species

Rhamnus spp. is known to contain biologically active anthraquinone secondary metabolites but the presence of oxyprenylated ones is not reported. To this aim, a new simple, and accurate analytical method was developed to reveal chemical fingerprint of these analytes in plant extracts. Plant samples were analysed after extraction with n-hexane (first step) and methanol (second step) using a C(18) column with a mobile phase composed of 35% of water:65% of methanol (both with 1% formic acid, v/v) at 0.7 mL min⁻¹ flow rate in gradient elution mode. For quantitative analyses, selective detection was performed at 435 nm. The limit of quantification (LOQ) was 0.5 μM, with the only exception of 3-geranyloxyemodin for which the LOQ value was 5.0 μM, and external matrix-matched standard curves showed linearity up to 125 μM. The within- and between-batch precision (RSD%) values ranged from 0.2% to 12.9% while within- and between-batch trueness (bias%) values ranged from 12.2% to 12.7%. The method was applied to evaluate for the first time the presence and the quantities of oxyprenylated anthraquinones in Rhamnus spp. barks as well as the anthraquinone profile of Rhamnus pumila Turra. The proposed method could be directly applied to the selective quantification of these analytes in natural sources.