Preparation and in vitro characterization of lipospheres as a carrier for the cosmetic application of glycolic acid

Lipospheres for the cosmetic delivery of glycolic acid were prepared by the melt method using tristearin as the lipid phase and hydrogenated soybean phosphatidylcholine as the emulsifier. The lipospheres, sized from 5 to 40 micron, contained a rather high glycolic acid loading level probably due to a partial polymorphic modification of the lipid and determined glycolic acid sustained release pattern

Sistema impiantabile per il rilascio di gentamicina: studio dell'interazione farmaco/polimero

Al fine di preparare e valutare un sistema impiantable in forma di sfere di calcio alginato per il rilascio di gentamicina nella prevenzione di infezioni ossee, è stata studiata l'interazione tra la gentamicina cationica e il polianione alginato mediante studio reologico. La gentamicina reagisce selettivamente sui residui mannuronici dell'alginato, mentre gli ioni calcio interagiscono preferenzialmente a livello delle sequenze poliguluroniche.Pertanto gli alginati a più alto contenuto di residui mannuronici dovrebbero essere considerati quali materiali più adatti per la preparazione dell'impianto

Beads of cross-linked carboxymethylcellulose: effect of the viscosity grade and concentration of the polymer

In order to evaluate the role of some preparative variables (viscosity grade and concentration of the polymer) on the release of soluble drugs, spherical matrices (beads) loaded with ambroxol hydrochloride were prepared by crosslinking with Al3+ sodium carboxymethylcellulose having different nominal viscosity grade in differently concentrated solutions

Distribuzione di farmaci in matrici caricate per rigonfiamento

Pellets di etilene/vinilacetato sono state caricate per rigonfiamento del polimero in soluzione cloroformica di tolbutamide, studiando le cinetiche di rigonfiamento e di caricamento del polimero mediante analisi EDX

Calcium alginate membrane coated matrices as oral drug delivery system

A translucent coat of calcium alginate with a wrinkled appearance was obtained around the PVA matrices. Increase in coating time led to an increase in the coat thickness and a decrease in drug content, also, a certain amount of drug appeared in the coat.The drug release was affected by the thickness and the pH-dependent behaviour of the coat. In fact, the drug was released from the swollen matrix through the intact coat in simulated gastric fluid and through the gelatinized coat in simulated intestinal fluid giving linear profiles, after a burst effect

Intragastric behaviour of a multiple unit floating system

This work aims to assay in humans the intragastric behaviour of an air compartment multiple unit delivery system able to float just placed into the gastric fluid and obtainable by a new simple technological approach. The floating system used in this study had shown an excellent buoyancy ability in a previous "in vitro" investigation (3). The "in vivo" floating time and the gastric residence time (GRT) of the floating system were determined by X-ray photographs and compared with those of a non-floating system in both fasted and fed states

Comportamento termico del fenilbutazone in presenza di silice colloidale

Le ricerche si sono focalizzate sul comportamento termodinamico del fenilbutazone caricato su un supporto di silice colloidale per deposizione da un solvente organico o per macinazione. Si \ue8 ottenuta una riduzione della cristallinit\ue0 del farmaco

The effect of alginate on PABA photostability

Photochemical modification of screening agents could have consequences in terms of photoprotection or phototoxicity. One of the most widely used UVB-absorbers is p-aminobenzoic acid (PABA). Published papers have reported that PABA decomposes and potentially harmful metabolities are formed by sun exposure, with also possible changes in screening efficiency, though discrepancy between the findings of some reports was noticed. Particularly, careful considerations should be given to a long-term use.Since the photochemical modification of PABA would involve the amino group, the present work attempts to increase the PABA photostability by forming a complex with sodium alginate, a polyanionic polysaccharide. The occurring of the complex between PABA and sodium alginate and the stability, before and after UV irradiation of PABA both alone and in a complex with alginate, were tested by monitoring the rheological and UV spectral changes