52 research outputs found
Critical concepts, practice recommendations, and research perspectives of pixantrone therapy in non-Hodgkin lymphoma: a SIE, SIES, and GITMO consensus paper
Objectives: In this paper, we present a review of critical concepts and research perspectives and produce recommendations on the optimal use of pixantrone in non-Hodgkin lymphoma (NHL) by group discussion from an expert panel appointed by the Italian Society of Hematology and the affiliate societies, Societa Italiana di Ematologia Sperimentale and Gruppo Italiano Trapianto di Midollo Osseo. Methods: Recommendations were produced using the Delphi process. Scientific evidence on pixantrone efficacy was analyzed using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology in the areas where at least one randomized trial was published. The following key issues were addressed for practical recommendations: pixantrone monotherapy in aggressive relapsed or refractory non-Hodgkin B-cell lymphomas and toxicity risk management in patients candidates to pixantrone. Results and conclusions: After a balanced and value-oriented discussion, the panel agreed that the benefit/risk profile was in favor of pixantrone in the treatment of adult patients with multiply relapsed or refractory aggressive NHL B-cell lymphomas. Pixantrone was deemed to be contraindicated in patients with uncontrolled cardiovascular disease. Despite a low rate of cardiotoxicity of pixantrone reported in clinical trials, the panel recommended that all patients receiving pixantrone should undergo periodical cardiac monitoring
Microencapsulation of semisolid ketoprofen/polymer microspheres
Ketoprofen controlled release microspheres were prepared, by emulsion/solvent evaporation, at 15 degreesC, in order to avoid the formation of semisolid particles. An identical procedure was carried out at 60 degreesC to speed up the solvent evaporation and the formed semisolid microspheres were directly microencapsulated by complex coacervation and spray-dried in order to recover them as free flowing powder. Microspheres and microcapsules were characterized by scanning electron microscopy, differential scanning calorimetry, X-ray diffractometry, in vitro dissolution studies, and then used for the preparation of tablets. During this step, the compressibility of the prepared powders was measured. Microspheres and microcapsules showed compaction abilities by far better than those of the corresponding physical mixtures. In fact, it was impossible to obtain tablets by direct compressing drug and polymer physical mixtures, but microspheres and microcapsules were easily transformed into tablets. Finally, in vitro dissolution studies were performed and the release control of the tablets was pointed out. Microspheres were able to control ketoprofen release only after their transformation into tablets. Tablets containing eudragit RS were the most effective in slowing down drug release
The role of side chains in the interaction of new antitumor pyrimidoacridinetriones with DNA: Molecular dynamics simulations.
Pyrimidoacridinetriones (PATs) are a new group of highly active antitumor compounds. It seems reasonable to assume that, like for some other acridine derivatives, intercalation into DNA is a necessary, however not a sufficient condition for antitumor activity of these compounds. Rational design of new compounds of this chemotype requires knowledge about the structure of the intercalation complex, as well as about interactions responsible for its stability. Computer simulation techniques such as molecular dynamics (MD) may provide valuable information about these problems. The results of MD simulations performed for three rationally selected PATs are presented in this paper. The compounds differ in the number and position of side chains. Each of the compounds was simulated in two systems: i) in water, and ii) in the intercalation complex with the dodecamer duplex d(GCGCGCGCGCGC)2. The orientation of the side chain in relation to the ring system is determined by the position of its attachment. Orientation of the ring system inside the intercalation cavity depends on the number and position of side chain(s). The conformations of the side chain(s) of all PATs studied in the intercalation complex were found to be very similar to those observed in water
Drug release from compressed Eudragit RS 30D coated beads
Tablets of different hardnesses and compositions were prepared with an original theophylline granulate previously coated with Eudragit RS 30D. Dissolution studies of each tablet formulation were performed to verify any kinetic variationfrom the dissolution profile. This was obtained by filling with the same coated granules in a hard gelatine capsule. While the dissolution profiles of the capsules possesses very good linearity, the tablet kinetics gradually deviate from this linearity with an increase in the percentage of the coated granules in the formulation. Tablet hardness has only a marginal influence on this kinetic deviation
Characterization and dissolution studies of PEG 4000/fenofibrate solid dispersions
Solid dispersions of fenofibrate in PEG 4000 were prepared by the solvent and fusion methods. The binary systems are successively studied and characterized using differential scanning calorimetry. X-ray diffractometry and Fourie transform infrared spectroscopy. Dissolution studies of the solid dispersed powders were performed to verify the water solubility improvement of the fenofibrate present in the formulations
Rheological, mucoadhesive and release properties of carbopol gels in hydrophilic cosolvents
Carbopol is one of the most common thickening agent for water phases. It is used after neutralisation and its rheological
properties in the aqueous medium are well known. The aim of this work was to investigate the gelation properties of Carbopol
971 e 974 polymeric systems in water-miscible cosolvents such as glycerine and PEG 400. Since in these cosolvents, carboxypolymethylene
precipitates after neutralisation with a base, then the attention was pointed out of the gelation properties of the
different systems at increasing temperature, in order to obtain Carbopols gels avoiding neutralisation and, at the same time,
making possible the dissolution in these gels of insoluble or poorly soluble water drugs. Rheological properties of PEG 400
and glycerine samples were compared with similar systems in water by performing oscillatory analyses and measuring the main
rheological parameters, G, G and ÎŽ. The results obtained showed that Carbopol 971 and 974 in PEG 400 gave rise after heating
to gels that show a satisfactory rheological behaviour. The elastic modulus is greater than the viscous one showing a remarkable
elastic character of these samples and the performed frequency sweeps show a typical spectrum of a âgel-likeâ structure. Being
Carbopols well-known mucoadhesive polymers, gels adhesive properties were studied using the ex vivo method. Then, the
possible cutaneous irritation were also tested using the in vivo method (Draize test). No signs of cutaneous irritation and good
mucoadhesive properties were obtained for the PEG 400 and water gels of Carbopol 974 prepared by heating.
After rheological and mucoadhesive properties were set, paracetamol as a model drug was then inserted in the composition of
the gels and the release characteristics were defined. Dissolution tests pointed out the greater release control properties of PEG
400-Carbopol 971 samples. These studies showed PEG 400-Carbopol systems as a first-rate alternative to traditional water gels
Interactions between Lonidamine and b- or hydroxypropyl -b- cyclodextrin
The possibility of obtaining inclusion complexes between lonidamine and ÎČ- or hydroxypropyl-ÎČ-cyclodextrin have been evaluated by phase solubility diagram, differential scanning calorimetry (DSC), and x-ray diffractometry. The applied complexation methods were spray-drying, kneading, and solid dispersion. DSC and x-ray analyses of the powders revealed an external interaction between lonidamine and cyclodextrins. Dissolution profiles of the obtained powders were also studied to define the most appropriate preparation method and molar ratio to use in attempts to increase lonidamine water solubility
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