Publications by authors named "Luisa Valvo"

This paper describes a case of medicine in disguise: seized tattoo inks containing lidocaine and tetracaine at high concentration. Identification of anaesthetics was performed by LC MS Q-TOF with ESI source, by accurate mass measurement and by comparing the fragmentation patterns of molecular ions, at 30 V and 10 V of collision-offset voltage, with reference standards. Quantification was also performed by LC MS Q-TOF on the chromatographic peaks in the extracted ion chromatograms, by calibration curves obtained at different standard concentrations and by standard additions approach.

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Adverse reactions have been reported for antibiotics produced via fermentation with fish peptone due to Histamine contamination. Just few micrograms of Histamine can result in adverse reactions when administered intravenously. Thus in this paper a new method for identification and quantitation of Histamine at ppm levels in the antibiotic Gentamicin is described.

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A nontargeted approach based on liquid chromatography equipped with a quadrupole time-of-flight mass detector (LC-MS Q-TOF) joined to nuclear magnetic resonance (NMR) analysis allowed rapid identification and quantification of the anti-inflammatory drug aceclofenac in illegal Adderall tablets. The largest chromatographic peak had m/z = 354.030 and m/z = 376.

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Objectives: The increasing illegal and on-line market of medicines and food supplements is helping the widespread diffusion of harmful counterfeit and forbidden products among consumers of developed countries. The objectives of this survey were the description of the main frauds recognized by public officers and the detection of illegal or counterfeit drugs and food supplements.

Methods: Medicines and food supplements found by Police forces on the illegal market or resulting from seizures made by Italian Customs authorities were visually inspected and analysed to evaluate their quality and the presence of other undeclared substances.

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Novel synthetic analogs of Sildenafil are constantly detected as adulterants in counterfeit drugs and dietary supplements. Their intake constitutes a serious health hazard as side effects are unknown. In this paper an investigation is carried out on NMR and MS/MS spectra of Sildenafil, Thiosildenafil, Acetildenafil and thirteen of their analogs: a list of key signals is reported and discussed with the intent to provide a tool that can help in detecting adulteration and in elucidating the structure of novel analogs.

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Introduction: In developed countries the phenomenon of pharmaceutical counterfeiting is steadily increasing through the illegal and the Internet market. Medicines for the treatment of erectile dysfunctions containing phosphodiesterase type 5 inhibitors (PDE5) are especially prone to falsification.

Aims: To obtain evidence of the health risks for patients taking these products and to provide useful information to general practitioners and specialists in sexual medicine.

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The growth of pharmaceutical counterfeiting is a major public health problem. This growth is resulting in a proportional increase in the number of samples that medicines control laboratories have to test. Thus the need for simple and affordable preliminary screening methods to be used by inspectors to decide in the field whether to collect a sample for further laboratory analysis or not.

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Background: The presence of counterfeits and sub-standards in African medicines market is a dramatic problem that causes many deaths each year. The increase of the phenomenon of pharmaceutical counterfeiting is due to the rise of the illegal market and to the impossibility to purchase branded high cost medicines.

Methods: In this paper the results of a quality control on antimalarial tablet samples purchased in the informal market in Congo, Burundi and Angola are reported.

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Calcitonin is a polypeptidic hormone involved in calcium metabolism in the bone. It belongs to the amyloid protein family, which is characterized by the common propensity to aggregate acquiring a beta-sheet conformation and include proteins associated with important neurodegenerative diseases. Here we show for the first time, to our knowledge, by transmission electron microscopy (TEM) that salmon-calcitonin (sCT) forms annular oligomers similar to those observed for beta-amyloid and alpha-sinuclein (Alzheimer's and Parkinson's diseases).

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Pharmaceutical counterfeiting is more and more a public health problem, especially in developing countries where the most counterfeit drugs are antibiotics, antimalarials and other life-saving drugs. The evaluation of the phenomenon extent is of great concern to the World Health Organization for carrying out a global strategy to combat the phenomenon. To this purpose, a reversed-phase liquid chromatographic method to perform the separation and simultaneous determination of three different kinds of antimalarial drugs (chloroquine, quinine and mefloquine) was developed.

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The natural ageing- and hydrogen peroxide-induced aggregation of salmon calcitonin were studied in water and in the presence of dipalmitoylphosphatidylcholine (DPPC) liposomes. The early stages of the aggregation process at low protein concentration were investigated by means of Circular Dichroism spectroscopy (CD) and conventional and immunogold labelling Transmission Electron Microscopy (TEM). In buffered water solution, salmon calcitonin showed a two-stage conformational variation related to fibril formation and phase-separation of larger aggregates.

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The aim of this work was to compare the dissolution behaviour of six diclofenac sodium prolonged release tablets of different brands obtained from the national market. The formulations contain the same amount of drug substance but different types and/or amount of excipients. The influence of these differences in formulation on the release characteristics of the dosage forms was evaluated on the European Pharmacopoeia apparatus 2 (paddle) employing eight different dissolution media in the pH range 1.

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The effects of hydroxyl radical attack on a peptidic drug were studied in vitro. Different chemico-physical techniques were used to investigate structural damage induced by oxidative stress conditions in salmon calcitonin (sCT), a peptide hormone used in treating osteoporosis. Reversed-phase liquid chromatography (RP-HPLC), circular dichroism (CD) and transmission electron microscopy (TEM) were applied to measure formation of oxidation/degradation products and to reveal the conformational and ultrastructural modifications in the presence of OH.

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A simple method for the simultaneous determination of zidovudine and nevirapine in human plasma by reversed-phase liquid chromatography with UV detection at 265 nm was developed. A solid-liquid extraction procedure with internal standard was applied to the samples prior to analysis. The system requires a Zorbax SB-C18 column, 250 x 4.

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