Giuseppe Fardella

Intercalation compounds of hydrotalcite-like anionic clays with antiinflammatory agents — I. Intercalation and in vitro release of ibuprofen

Hydrotalcite-like compounds are layered solids having positively charged layers and interlayer charge-compensating anions. The synthetic Mg0.67Al0.33(OH)2 Cl0.33.0.6H2O, which is biocompatible, has been used to intercalate a model drug, ibuprofen, in order to prepare a modified release formulation. The intercalation compound was prepared via ion-exchange starting from the chloride form of hydrotalcite and its composition, determined both by elemental microanalysis and thermogravimetric analysis, was Mg0.67Al0.33(OH)2IBU0.33.0.47H2O, drug content 50% (w/w). As a consequence of the intercalation, the interlayer distance of the host increased from 0.78 nm (interlayer distance of chloride form) to 2.17 nm. The result of dissolution tests at pH 7.5 showed that the in vitro drug release was modified if compared with that obtained with comparative formulations. The mechanism of modified drug release has been interpreted on the basis of the ion exchange process of the ibuprofen anion intercalated in the lamellar host and phosphates contained in the intestinal fluid buffer.

Intercalation compounds of hydrotalcite-like anionic clays with anti-inflammatory agents, II: Uptake of diclofenac for a controlled release formulation

The purpose of this study was to investigate whether hydrotalcite is able to intercalate diclofenac, a nonsteroidal anti-inflammatory drug, and release it in a controlled manner. Layered Mg−Al hydrotalcite in the chloride form was used as a host, and the intercalation compound was prepared by Cl−/diclofenac anionic exchange. Drug release from the intercalation compound was performed in vitro in simulated intestinal fluid at pH 7.5 according to USP 24 and in a pH 7.0 solution designed to mimic the ionic conditions of the small intestine. Results from the intercalation process show that hydrotalcite is able to intercalate diclofenac with a simple procedure and with a good drug loading (55% wt/wt). The in vitro drug release was remarkably lower than that from the corresponding physical mixture at both pH 7.5 and pH 7.0. In the latter case, the release was not complete at 24 hours. The kinetic analysis shows the importance of the diffusion through the particle in controlling the drug release rate. The obtained results show that hydrotalcite may be used to prepare modified release formulations.

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.

Isolation and structure of a quassinoid from Ailanthus glandulosa

Abstract A new quassinoid, 2-dihydroailanthone, has been isolated from the bark of Ailanthus glandulosa . Its structure was established on the basis of spectroscopic data and chemical evidence.

Glaucopine C, a new diterpene from the fruiting bodies of Sarcodon glaucopus

In this work the mushroom Sarcodon glaucopus was studied. A new cyathane, glaucopine C (1), was isolated from the hexane extract and identified by 1H and 13C NMR spectra analysis. Glaucopine C showed anti-inflammatory acitvity.

A new neoquassin derivative from Quassia amara

Abstract A new quassinoid, a dihydronorneoquassin, has been isolated from Quassia amara wood. In addition the known compounds, paraine and isoparaine, were

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.

Quassinoids from Quassia amara

Abstract Three new quassinoids, 11-α- O -(β- d -glucopyranosyl)-16-α- O -methylneoquassin, 1-α- O -methylquassin and 12-α-hydroxy-13,18-dehydr