108 research outputs found
Development of a transdermal patch for delivery of propafenone: preliminary studies in vitro
No full textPropafenone, a well-known antiarrhythmic drug, has a low oral bioavailability due to extensive hepatic first-pass metabolism The present study was aimed at verifying, on a preliminary basis, feasibility of transdermal delivery of the drug. Propafenone is apparently unable to penetrate the skin in the absence of appropriate enhancers. Different prospective enhancers (terpenes, azone) for the drug hydrochloride and base were evaluated in vitro using hairless mouse skin. Propafenone hydrochloride and atone, the most favourable drug species and enhancer combination, were then incorporated into semisolid vehicles, designed to act as reservoirs in transdermal patches. The patches, with and without a microporous membrane and adhesive layer were then tested for transdermal release using the same in vitro model. Skin, not membrane permeation, was found to be the rate-limiting step in delivery from the final patches. These, after 5 to 6 h lag times, delivered propafenone hydrochloride at a constant rate (5.4 to 27.5 mu g/cm(2)/h) for over 48 h. Since the literature data on intravenous infusion of propafenone appear to indicate the need for higher rates, further research on more effective promoters and transdermal patches is in progres
Substantive sunscreens as anti-ageing agents: structure-activity relationships
No full textThe aim of the study was verify he skin penetration of the highly skin-substantive quaternary ammonium derivatives, in comparison with their parent, non-quaternarized compounds
[Formulations containing complexes of ophthalmic drugs with tannic acid: "in vitro" and "in vivo" evaluation]. FT Formulazioni contenenti complessi di farmaci oftalmici con acido tannico: preparazione e valutazione "in vitro" e "in vivo".
No full textPreparation and preliminary evaluation of liposomal formulations for ocular delivery of vancomycin
No full textSubstantivity of sunscreens. In vitro evaluation of the transdermal permeation characteristics of some benzophenone derivatives
No full textThe in vitro permeation through excised hairless mouse skin of a series of 4-O-(N, N-dimethylaminoalkyl)-benzophenones, non-quaternarized and quaternarized, and of two commercial benzophenone sunscreens, taken as reference compounds, was investigated. The aim of the study was to verify the skin penetration of the highly skin-substantive quaternary ammonium derivatives, in comparison with their parent, non-quaternarized compounds. While the quaternary derivatives proved unable to permeate the skin during the period of observation (45 h), their parent amine hydrochlorides and the reference sunscreens (2-hydroxy-4-methoxy-benzophenone-5-sulphonic acid and 2,2′-dihydroxy-4,4′-dimethoxy-benzophenone 5,5′-sodium disulphonate), showed appreciable transdermal fluxes.
These data indicate that the presence of a quaternary ammonium group in a molecule, besides inducing a high affinity for cutaneous keratin, may result in hindered or reduced transdermal (and possibly systemic) absorption. Both features may contribute in improving the safety of a cosmetic sunscreen
[Ophthalmic mucoadhesive vehicles: preliminary study of ocular pharmacokinetics "in vivo"]. FT Veicoli oftalmici mucoadesivi: studio preliminare della farmacocinetica oculare "in vivo".
No full text
Preparati oftalmici a base di polisaccaridi mucoadesivi con capacità riepitelizzante della cornea
No full textSoluzioni oftalmiche contenenti arabinogalactans con una attività protettiva sull'epitelio corneale, particolarmente adatto per l'uso come lacrime artificiali stimolare la ripresa delle lesioni corneali e anche particolarmente utile per gli utenti di lenti a contatto, contenenti da 1% al 10% in peso di Arabinogalattano in una soluzione acquosa ed eventuali altri eccipienti, tra cui tonicità-regolatori dell'acidità, gli correttori di pH, tamponi e conservanti, ad eccezione di benzalconio cloruro.
Le composizioni secondo l'invenzione ha una viscosità pressoché trascurabile, ma sono sufficientemente mucoadesive per garantire un tempo di permanenza nel campo di applicazione.
Oltre ad essere ben tollerato, i suddetti composizioni hanno notevoli capacità di riepitelizzazion
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