1,721,037 research outputs found
Complexation of phenytoin with some hydrophilic cyclodextrins: effect on aqueous solubility, dissolution rate, and anticonvulsant activity in mice
No full textComparative study among some potential dermal formulations intended for glutathione administration
No full textComparative study of dissolution properties and anticonvulsant activity in rats between novel solid dosage forms of valproic acid and sodium valproate
No full textA histochemical approach to glycan diversity in the urothelium of pig urinary bladder
Full text linkIntracellular glycans in the urothelium of urinary bladder of 10 adult male Landrace pigs were characterized in situ by immunohistochemical detection of Muc1 mucin by anti MUC1 from rabbit, conventional histochemical techniques (Periodic-Acid Schiff, Alcian Blue pH 2.5, High-Iron Diamine), and binding with 13 lectins (PNA, DBA, RCA-I, WGA, SBA, BSI-B4, ConA, AAA, UEA-I, LTA, LFA, MAA-II, SNA) combined with chemical and enzymatic pre-treatments (β-elimination, desulfation and neuraminidase) to gather reference data for this model animal. Muc1 mucin was detected in the secreting granules of superficial cells and the underlying layer of intermediate cells. The secreting granules in both intermediate cells and superficial cells were rich in carbohydrates, with the oligosaccharidic chains mostly O-linked to proteins. Glycoproteins were prevailing over glycosaminoglycans (GAGs). In both superficial and intermediate cells sulfated and/or sialylated glycans were present, sulfation decreasing in the deeper layers. Lectin-binding detected presence of terminal sialic acid linked mostly in α2,6 to GalNAc, Gal terminal or subterminal to sulfates, GalNAc, GlcNAc, and Fuc, mostly linked in α1,6, α1,3 α1,4 and α1,2 to GlcNAc or Gal, but not to lactosamine chains. Except for fucosylation, the oligosaccharidic chains in the glycoproteins of the urothelium of pig urinary bladder were similar to those linked to human MUC1, which is fundamental in cell adhesion and immunological processes in the urothelium. The co-distribution of Muc1 and saccharidic residues suggests that many of them are linked to the glycoprotein
Combined Eudragit RS100 cyclodextrin nanoparticles intended for transmucosal administration of Glutathione
No full textNew nanostructured self-assemblong inulin-a-tocopherol bioconjugates for biomedical applications
No full textNew conjugates between inulin (INU) and vitamin E (VITE) able to form amphiphilic systems self-assembling in nanostructures thought for biomedical applications such as the therapy of urinary tract affections were prepared.
This work, shows the syntheses, characterization and self-assembling properties of the obtained polymeric conjugates (INVITE).
The reaction between VITE and INU has been carried out in bulk, without isolation of intermediate products leading to a convenient one-step reaction. To tailor the physical-chemical characteristics of the INVITE bioconjugate, six different INVITE conjugates were obtained by varying the relative amount of bonded VITE respect to INU repeating units.
The obtained products were characterized by 1H-NMR, 13C-NMR, FT-IR and DSC. Furthermore, to verify that VITE does not undergo any oxidation during the reactions, UV-VIS analyses have been performed and the ability of the new conjugates to form nanoparticulate systems in water or 0.9 % saline was performed by dynamic light scattering. Furthermore, in the same media, was evaluated the stability of the INVITE nanosystems after incubation at 25 °C up to 12 days, by measuring at different time points their size variation. The degree of derivatization was found not influenced by the temperature, but it mostly depend from the different molar ratios. Interestingly, the introduction of VITE in the inulin backbone resulted almost quantitative.
All conjugates resulted self-assembling in water forming nanosystems sized below 100 nm. The nanosystems are stable and do not aggregate after 12 days incubation. These results strongly encourage to prove these systems for drug delivery applications
Eudragit RS 100 nanoparticles containing cyclodextrins intended for transmucosal route of glutathione
No full textFrog intestinal sac as an in vitro method for the assessment of intestinal permeability in humans: Application to carrier transported drugs
No full textThe aim of this study was to investigate the presence of pharmaceutically relevant drug transporters in frog intestine which has been proposed
as model for intestinal permeability screening assays of passively absorbed drugs in humans [Trapani, G., Franco, M., Trapani, A., Lopedota, A.,
Latrofa, A., Gallucci, E., Micelli, S., Liso, G., 2004. Frog intestinal sac: a new in vitro method for the assessment of intestinal permeability. J.
Pharm. Sci. 93, 2909–2919]. The expression of transporters in frog intestine was supported by the following observations: (i) the involvement of
purine nucleobase transport system was deduced by inhibition of acyclovir transport in the presence of adenine; (ii) baclofen or l-dopa transport
was inhibited by the digitalis steroid ouabain and it may be related to the Na+ electrochemical potential difference, presumably involving amino
acid transporters; (iii) the presence of proton-dependent peptide transporters was argued evaluating the effect of the pH change (from pH 5.9 to
pH 7.4) on the transport of glutathione; (iv) the possible expression in the frog intestine of an efflux system distinct from P-glycoprotein (Pgp)
in the benzylpenicillin transport was deduced using a glucose enriched frog Ringer with or without the known Pgp inhibitor verapamil; (v) the
contribution of Pgp-mediated efflux system in determining the frog intestinal absorption of drugs was supported by the specific inhibition of
cimetidine or nadolol transport in the presence of verapamil. These results indicate that pharmaceutically relevant drug transporters should be also
expressed in frog intestine.
In this work, an attempt was also made to compare the measured Papp values in the frog intestinal model for the aforementioned series of
actively/effluxed transported drugs in humans to the corresponding literature values for the fraction absorbed. The Papp values used in these
comparisons were obtained at high concentrations of drugs at which probably saturation of the carrier occurs. Interestingly, it was found that drugs
that are completely absorbed had Papp values >3×10−6 cm/s, while drugs absorbed <90% had Papp values lower than 1×10−6 cm/s. In these
cases, indeed, a borderline region characterized by the apparent permeability coefficient Papp value between 1×10−6 and 3×10−6 cm/s should
be considered for which the prediction of the absorbed fraction after oral administration in humans become more uncertain by the frog intestinal
sac system
SPRAY DRIED MICROPARTICLES OF CHITOSAN OR ITS THIOLIC DERIVATES FOR CELECOXIB INTRAVESCICAL DELIVERY
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