Ione Chiappini

Quantitative analysis of fluoroquinolones by 1H- and 19F-NMR spectroscopy

Abstract 1H- and 19F-NMR assay of pefloxacin (I), norfloxacin (II) and ofloxacin (III) in some pharmaceutical forms has been developed. The method, based on the integration of appropriate signals of both analytes and internal standards, is simple, rapid, precise, and accurate, and can be used for quality control of these drugs.

Unilamellar Vesicles as Potential Capreomycin Sulfate Carriers: Preparation and Physicochemical Characterization

The aim of this work was to evaluate unilamellar liposomes as new potential capreomycin sulfate (CS) delivery systems for future pulmonary targeting by aerosol administration. Dipalmitoylphosphatidylcholine, hydrogenated phosphatidylcholine, and distearoylphosphatidylcholine were used for liposome preparation. Peptide-membrane interaction was investigated by differential scanning calorimetry (DSC) and attenuated total internal reflection Fourier-transform infrared spectroscopy (ATIR-FTIR). Peptide entrapment, size, and morphology were evaluated by UV spectrophotometry, photocorrelation spectroscopy, and transmission electron microscopy, respectively. Interaction between CS and the outer region of the bilayer was revealed by DSC and ATIR-FTIR. DSPC liposomes showed enhanced interdigitation when the CS molar fraction was increased. Formation of a second phase on the bilayer surface was observed. From kinetic and permeability studies, CS loaded DSPC liposomes resulted more stable if compared to DPPC and HPC over the period of time investigated. The amount of entrapped peptide oscillated between 10% and 13%. Vesicles showed a narrow size distribution, from 138 to 166 nm, and a good morphology. These systems, in particular DSPC liposomes, could represent promising carriers for this peptide.

New cytotoxic selenoderivatives of guaianolides

Abstract A series of 13-phenylselenoderivatives of natural and semisynthetic guaianolides were prepared and their cytotoxicity tested in vitro against KB cell cultures. Generally the presence of the 13-Se-phenyl group led to an increased bioactivity ( ID 50 ) supporting the hypothesis that it may act as a “masked” α-methylene-γ-lactone group.

Microporous material from kanemite for drug inclusion and release

A microporous material obtained from kanemite, a layered polysilicate, was studied in order to investigate its feasibility of including drugs and then releasing them. Diphenydramine hydrochloride was chosen as a model drug. The preparation of the microporous material and its loading with the drug are described. As kanemite is able to intercalate anions between its layers, the intercalation compound of diphenydramine and kanemite was also prepared. Both the drug-loaded microporous material and the intercalation compound were submitted to dissolution tests at pH 7.5. The drug release profiles from these two different materials and from a physical mixture were compared.

Grosulfeimin and New Related Guaianolides from Cynara Scolymus L

Abstract Three new guaianolides, 11-H-13-methylsulfonylgrosheimin (5) (grosulfeimin), 8-deoxy-11, 13-dihydroxygrosheimin (7) and 8-deoxy-11-hydroxy-13-chlorogrosheimin (8) have been isolated from the leaves of Cynara scolymus L. Furthermore, the already known 8-epigrosheimin (9) has been isolated for the first time from this source. The structures were determined by both spectroscopical methods and chemical correlations.

Thiol Gel as a Matrix for Binding-Release of α,β-Unsaturated Sesquiterpene Lactones

The hydrogel thiopropyl‐sepharose 6B was used as a model matrix system to bind the natural cytotoxic sesquiterpene lactones grosheimin 1 and deacylcynaropicrin 2. The hydrogel thio groups were bonded to the lactone exomethylene groups and the release of the lactones from the polymer was studied. Since it is thought that cancer cells have a higher oxidative potential than normal cells, the release was carried out through an oxidative cleavage. Different concentrations of hydrogen peroxide solutions were added to the lactone‐polymer conjugates, thus, imitating in vivo conditions. The results obtained showed that both the rate and amount of grosheimin and deacylcynaropicrin release depend linearly on the H2O2 concentration.