Brain uptake of an anti-ischemic agent by nasal administration of microparticles.

N(6)-cyclopentyladenosine (CPA) has neuronal anti-ischemic properties, but it is not absorbed into the brain from the bloodstream, where it shows poor stability and induces side effects. Microparticulate drug delivery systems designed for CPA nasal administration and constituted by mannitol or chitosan, were prepared by spray-drying and characterized. Mannitol-lecithin microparticles showed high CPA dissolution rate, whereas chitosan microparticles controlled its release rate.

Solid lipid microparticles for the stability enhancement of the polar drug N6-cyclopentyladenosine.

The objective of this study was to prepare solid lipid microparticles (SLMs) loaded with the polar adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA). The microparticles were produced by the conventional hot emulsion technique, using different lipidic carriers (tristearin, glyceryl behenate and stearic acid) and hydrogenated phosphatidylcholine as the surfactant. The controlled release of CPA was achieved only with stearic acid microparticles.

Non-phospholipid vesicles as carriers for peptides and proteins: production, characterization and stability studies.

In the present study, the preparation, characterization and activity of non-phospholipid vesicles (NPV) containing three aminoacid-based molecules were described. As model compounds trypsin, bovine basic pancreatic inhibitor and polylysine rich peptides derived from the herpes simplex virus type 1 (HSV-1) glycoprotein B were employed. NPV were chosen as alternative to liposomes for the possible administration of aminoacid based molecules via mucous membrane (nasal or vaginal) routes.

Molecular mechanism involved in the transport of a prodrug dopamine glycosyl conjugate.

We have previously demonstrated that dopamine conjugation to glucose allows it to induce therapeutic effects against Parkinson's disease after intravenous administration. In this paper we demonstrate that, unlike dopamine, the prodrug glu-dopamine is a transportable substrate of glucose transporters. Towards this, the effect of glucose-conjugation on the affinity and uptake of dopamine have been assessed in vitro, using human retinal pigment epithelium (HRPE) cells.

Polymeric nanoparticles as drug controlled release systems: a new formulation strategy for drugs with small or large molecular weight.

We report a study evaluating the encapsulation and release modalities from poly(D,L lactic acid) (PLA) or poly(D,L-lactide-co-glicolide) (PLGA) micro- and nano-particles of the antiischemic drug N6-cyclopentyladenosine (CPA) and bovine serum albumin (BSA), chosen as protein model. The results obtained by classical preparation methods (nanoprecipitation, single or double emulsion/solvent evaporation) of the particles were compared with those obtained by their formulation with a novel method, employing a thermosensible gel of Pluronic F-127, whose aqueous solutions can be liquid when refrigerated, but gel upon warming. Our results indicate that CPA-loaded nanoparticles, obtained by classical methods, drastically reduce their drug content showing, moreover, any control of the drug release with respect to CPA-loaded microparticles.