Biomedical subjects

Enea Menegatti

Publications and source records attributed to Enea Menegatti.

18 recordsLinked to original sources

PubMed2006

Cellulose acetate butyrate-pH/thermosensitive polymer microcapsules containing aminated poly(vinyl alcohol) microspheres for oral administration of DNA.

The aim of this work is to safely transport bioadhesive microspheres loaded with DNA to intestine and to test their bioadhesive properties. Poly(vinyl alcohol) (PVA) microspheres were prepared by dispersion reticulation with glutaraldehyde and further aminated. These microspheres were firstly loaded with plasmid DNA by electrostatic interactions and then entrapped in cellulose acetate butyrate (CAB) microcapsules for gastric protection. The entrapped PVA microspheres do not have enough force by swelling to produce the rupture of CAB shell, therefore the resistance of microcapsules was weakened by incorporating different amount of the pH/thermosensitive polymer (SP) based on poly(N-isopropylacrylamide-co-methyl methacrylate-co-methacrylic acid) (NIPAAm-co-MM-co-MA). This polymer is insoluble in gastric juice at pH 1.2 and 37 degrees C, but quickly solubilized in intestinal fluids (pH 6.8 and pH 7.4). Therefore, DNA loaded PVA microspheres were not expelled in acidic media but were almost entirely discharged in small intestine or colon. The integrity of DNA after entrapment was tested by agarose gel electrophoresis indicating that no DNA degradation occurs during encapsulation. The percentage of adhered microspheres on the mucus surface of everted intestinal tissue was 65+/-18% for aminated PVA microspheres without DNA and almost 50+/-15% for those loaded with DNA. Non-aminated PVA microspheres display the lowest adhesive properties (33+/-12%). In conclusion DNA loaded microspheres were progressively discharged in intestine. The integrity of DNA was not modified after entrapment and release, as proved by agarose gel electrophoresis. Both loaded and un-loaded aminated microspheres display good bioadhesive properties.

Administration, Oral↗

PubMed2006

CO2 impairs peroxynitrite-mediated inhibition of human caspase-3.

Peroxynitrite (ONOO-) is a transient powerful oxidant produced in vivo as the reaction of nitrogen monoxide (.NO) with superoxide (O2.-). The peroxynitrite reactivity is modulated by carbon dioxide (CO2) which enhances the peroxynitrite-mediated nitration of aromatics and partially impairs the oxidation of thiols. Here, the effect of CO2 on the peroxynitrite-mediated inhibition of human caspase-3, the execution enzyme of the apoptotic cascade, is reported. Peroxynitrite inhibits the catalytic activity of human caspase-3 by oxidizing the Sgamma atom of the Cys catalytic residue. In the absence of CO2, 1.0 equivalent of peroxynitrite inactivates 1.0 equivalent of human caspase-3. In the presence of the physiological concentration of CO2 (=1.3x10(-3) M), 1.0 equivalent of peroxynitrite inactivates only 0.38 equivalents of human caspase-3. Peroxynitrite affects the kcat value of the human caspase-3 catalyzed hydrolysis of N-acetyl-Asp-Glu-Val-Asp-7-amido-4-methylcoumarin, without altering Km. Both in the absence and presence of CO2, the reducing agent dithiothreitol does not prevent human caspase-3 inhibition by peroxynitrite and does not reverse the peroxynitrite-induced inactivation of human caspase-3. These results represent the first evidence for modulation of peroxynitrite-mediated inhibition of cysteine proteinase action by CO2, supporting the role of CO2 in fine tuning of cell processes (e.g., apoptosis).

Apoptosis↗

PubMed2005

Preparation and characterisation of thermoresponsive poly[(N-isopropylacrylamide-co-acrylamide-co-(hydroxyethyl acrylate)] microspheres as a matrix for the pulsed release of drugs.

Despite the large number of publications and patents concerning pH/thermoresponsive polymers, few data are available concerning the preparation of thermoresponsive cross-linked microspheres from preformed polymers. Therefore, N-isopropylacrylamide-co-acrylamide-co-(2-hydroxyethyl acrylate) copolymers were obtained as a new thermoresponsive material with a lower critical solution temperature (LCST) around 36 degrees C, in phosphate buffer at pH 7.4, and with a cross-linkable OH group in their structure. The LCST value was determined both by UV spectroscopy and microcalorimetric analysis. These copolymers were solubilised in acidified aqueous solution below their LCST, dispersed in mineral oil, and transformed into stable microspheres by cross-linking with glutaraldehyde. The thermoresponsive microspheres were characterised by optical and scanning electron microscopy, degree of swelling, and water retention. The pore dimensions of the microspheres and the retention volumes of some drugs and typical compounds were evaluated at different temperatures by liquid chromatography. Indomethacin, as a model drug, was included in the microspheres by the solvent evaporation method. Finally, the influence of temperature and of temperature cycling on drug release was investigated.

Acrylamides↗

PubMed2005

Heme impairs allosterically drug binding to human serum albumin Sudlow's site I.

Human serum albumin (HSA), the most prominent protein in plasma, is best known for its exceptional ligand (e.g., heme and drugs) binding capacity. Here, the binding of chlorpropamide, digitoxin, furosemide, indomethacin, phenylbutazone, sulfisoxazole, and tolbutamide to HSA and ferric heme-HSA is reported. Moreover, ferric heme binding to HSA in the absence and presence of drugs has been investigated. Values of the association equilibrium constant for drug binding to Sudlow's site I of ferric heme-HSA (ranging between 1.7 x 10(3) and 1.6 x 10(5)M(-1)) are lower by one order of magnitude than those for drug binding to ferric heme-free HSA (ranging between 1.9 x 10(4) and 1.8 x 10(6)M(-1)). According to linked functions, the value of the association equilibrium constant for heme binding to HSA decreases from 7.8 x 10(7)M(-1), in the absence of drugs to 7.0 x 10(6)M(-1), in the presence of drugs. These findings represent a clear-cut evidence for the allosteric inhibition of drug binding to HSA Sudlow's site I by the heme. According to linked functions, drugs impair allosterically heme binding to HSA. These results appear to be relevant in the drug therapy and management.

Allosteric Site↗

PubMed2005

Hyaluronan-based microspheres as tools for drug delivery: a comparative study.

The present paper describes the production of biodegradable microparticles using different hyaluronan polymers, such as native hyaluronan, the esterified derivative of hyaluronan Hyaff 11p50 (where 50% of the carboxy groups of hyaluronic acid are esterified with benzyl alcohol) and the autocross-linked polymer (ACP) internally esterified derivative of hyaluronan, by solvent evaporation and spray-drying methods. As model drugs cromolyn sodium salt, metronidazole and prednisolone hemisuccinate sodium salt were employed. The influence of polymer and preparation procedure has been evaluated on microparticle characteristics (i.e. morphology and encapsulation yield) and on the drug release profiles. The use of solvent evaporation method, a polymeric matrix constituted of Hyaff 11p50 3% (w/v), a dispersing phase constituted of 80 g of mineral oil (w/o ratio: 0.1), Span 85 0.1% (w/w) as stabilizer, and a stirring speed of 700 rpm resulted in the production of microspheres characterized by spherical shape, absence of aggregates, a mean diameter of 6.4 microm and a recovery of 90% (w/w). The production of drug containing microspheres led to an increase of mean diameter of microspheres and to high encapsulation yields. Moreover in vitro models have demonstrated that in all cases drugs were released from Hyaff 11p50 microspheres in a controlled fashion. Finally mathematical analysis of the drug release modalities has evidenced that drug release from Hyaff 11p50 microspheres is more consistent with kinetics of the diffusion rather than of the dissolution type.

Drug Delivery Systems↗

PubMed2005

Cubosome dispersions as delivery systems for percutaneous administration of indomethacin.

PURPOSE: The present study concerns the production and characterization of monooleine (MO) dispersions as drug delivery systems for indomethacin, taken as model anti-inflammatory drug. METHODS: Dispersions were produced by emulsification and homogenization of MO and poloxamer in water. Morphology and dimensional distribution of the disperse phase have been characterized by cryo-transmission electron microscopy and photon correlation spectroscopy, respectively. X-ray diffraction has been performed to determine the structural organization of the disperse phase. Sedimentation field flow fractionation (SdFFF) has been performed to investigate drug distribution in the dispersion. An in vitro diffusion study was conducted by Franz cell associated to stratum corneum epidermis membrane on cubosome dispersions viscosized by carbomer. In vivo studies based on skin reflectance spectrophotometry and tape stripping were performed to better investigate the performance of cubosome as indomethacin delivery system. RESULTS: Microscopy studies showed the coexistence of vesicles and cubosomes. X-ray diffraction revealed the presence of a bicontinuous cubic phase of spatial symmetry Im3m (Q229). SdFFF demonstrated that no free drug was present in the dispersion. Indomethacin incorporated in viscosized MO dispersions exhibited a lower flux with respect to the analogous formulation containing the free drug in the aqueous phase and to the control formulation based on carbomer gel. Reflectance spectroscopy demonstrated that indomethacin incorporated into MO dispersions can be released in a prolonged fashion. Tape-stripping experiments corroborated this finding. CONCLUSIONS: MO dispersions can be proposed as nanoparticulate systems able to control the percutaneous absorption of indomethacin.

Adult↗

PubMed2005

Cellulose acetate butyrate microcapsules containing dextran ion-exchange resins as self-propelled drug release system.

Sulfopropylated dextran microspheres (SP-Ms), (Dm = 80 microm) loaded with a water soluble drug (Tetracycline HCl), were included in cellulose acetate butyrate (CAB) microcapsules. Spherical CAB microcapsules were obtained by oil in water (o/w) solvent evaporation method in the presence of an inert solvent as cyclohexane (CyH) or n-hexane (N-Hex), and different excipients (Phospholipon, Tween, Span, Eudragit RS 100). Chloroform was found to be the best solvent for the preparation of the microcapsules. Also, the sphericity as well as the porosity of the microcapsules was controlled by the presence of an inert solvent. The final concentration of the drug in CAB microparticles was up to 25% (w/w). The key factors for the successful preparation were also the viscosity of the polymer, while the wettability of the resulted microcapsules, the temperature of the preparation, and the porosity have modulated the release of the drug. The higher is the amount of encapsulated microspheres the thinner is the CAB wall between the compartments created by their incorporation. When these microspheres come in contact with the release medium, the pressure created by their swelling breaks the polymer film and the drug starts to be released. The more drug is released in phosphate buffer the higher is the swelling degree of the encapsulated ion exchange resins and the force created by their supplementary swelling will break the more resistants walls. In this way a self-propelled drug release is achieved, until almost all drug was eliberated.

Anti-Bacterial Agents↗

PubMed2005

Allosteric modulation of anti-HIV drug and ferric heme binding to human serum albumin.

Human serum albumin (HSA), the most prominent protein in plasma, is best known for its exceptional capacity to bind ligands (e.g. heme and drugs). Here, binding of the anti-HIV drugs abacavir, atazanavir, didanosine, efavirenz, emtricitabine, lamivudine, nelfinavir, nevirapine, ritonavir, saquinavir, stavudine, and zidovudine to HSA and ferric heme-HSA is reported. Ferric heme binding to HSA in the absence and presence of anti-HIV drugs was also investigated. The association equilibrium constant and second-order rate constant for the binding of anti-HIV drugs to Sudlow's site I of ferric heme-HSA are lower by one order of magnitude than those for the binding of anti-HIV drugs to HSA. Accordingly, the association equilibrium constant and the second-order rate constant for heme binding to HSA are decreased by one order of magnitude in the presence of anti-HIV drugs. In contrast, the first-order rate constant for ligand dissociation from HSA is insensitive to anti-HIV drugs and ferric heme. These findings represent clear-cut evidence for the allosteric inhibition of anti-HIV drug binding to HSA by the heme. In turn, anti-HIV drugs allosterically impair heme binding to HSA. Therefore, Sudlow's site I and the heme cleft must be functionally linked.

Allosteric Regulation↗

PubMed2005

Effect of charge and lipid concentration on in-vivo percutaneous absorption of methyl nicotinate from liposomal vesicles.

We have investigated the influence of charge and lipid concentration on the in-vivo percutaneous absorption of a model compound, methyl nicotinate (MN), from liposomal vesicles. MN-loaded liposomes were produced by the reverse-phase evaporation method (REV) using different concentrations of phosphatidyl choline (PC), in association with surfactants such as dioctadecyl dimethyl ammonium bromide (DDAB18) and dicetyl phosphate (DCP), which impart a positive or negative charge to the systems, respectively. The liposomal suspensions were then processed to hydrogels and used to study in-vivo the MN permeation profile. MN was chosen as the model compound since it was capable of causing cutaneous erythema, the intensity and duration of which was proportional to the amount entering the living epidermis over time. The extent of the erythema was monitored by reflectance spectrophotometry, a non-invasive technique. In-vivo findings showed an interesting MN delayed release, which was proportional to the amount of phospholipids in each liposomal formulation. Furthermore, it could be noted that the erythematous effect was more prolonged when MN was delivered from neutral or negatively-charged liposomal forms.

Administration, Topical↗

PubMed2004

Preparation and characterisation of poly(vinyl alcohol)/cyclodextrin microspheres as matrix for inclusion and separation of drugs.

Poly(vinyl alcohol) (PVA) microspheres containing cyclodextrin (CD) were obtained by chemical cross-linking with glutaraldehyde of an acidified mixture solution of PVA and alpha-, beta- or gamma-CD. The amount of linked CD in microspheres, estimated by tetrazolium blue method, decreases in the order beta- > gamma- > alpha-CD. The dimensions of PVA/gamma-CD microspheres are much higher than those of PVA/alpha- and beta-CD. The cross-linking density of microspheres was estimated by the amount of iodine retained by the polymer matrix. The pore size as well as the porous volume of PVA/CD microspheres decrease significantly on increasing the amount of glutaraldehyde, but are enough large to permit the access of drugs to the CD cavity. In order to test the PVA/CD microsphere inclusion ability, the microspheres were packed in a glass column and the liquid chromatographic behaviour by isocratic elution of different drugs or typical organic compounds, taken as model drugs, was investigated.

Chemistry, Pharmaceutical↗

PubMed2004

Kinetics of parasite cysteine proteinase inactivation by NO-donors.

NO-donors block Plasmodium, Trypanosoma, and Leishmania life cycle inactivating parasite cysteine proteinases. In this study, the inactivation of falcipain, cruzipain, and Leishmania infantum cysteine proteinase by S-nitroso-5-dimethylaminonaphthalene-1-sulphonyl (dansyl-SNO), S-nitrosoglutathione (GSNO), (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (NOR-3), and S-nitrosoacetylpenicillamine (SNAP) is reported. With NO-donors in excess over the parasite cysteine proteinase, the time course of enzyme inactivation corresponds to a pseudo-first-order reaction for more than 90% of its course. The concentration dependence of the pseudo-first-order rate constant is second-order at low NO-donor concentrations but tends to first-order at high NO-donor concentrations. This behavior may be explained by a relatively fast pre-equilibrium followed by a limiting pseudo-first-order process. Kinetic parameters of cruzipain inactivation by GSNO were affected by the acidic pK shift of one ionizing group (from pKunl = 5.7 to pKlig = 4.8) upon GSNO-induced enzyme inactivation. Falcipain, cruzipain, and L. infantum cysteine proteinase inactivation by dansyl-SNO, GSNO, NOR-3, and SNAP is prevented and reversed by dithionite and l-ascorbic acid. However, the incubation of L. infantum cysteine proteinase with dansyl-SNO does not result in the appearance of fluorescence of the enzyme. More than 90% of the S-transnitrosylation product GSH existed in the inactivation reaction, suggesting that S-transnitrosylation is the favorite process for parasite cysteine proteinase inactivation. Furthermore, the fluorogenic substrate N-alpha-benzyloxycarbonyl-l-phenylalanyl-l-arginine-(7-amino-4-methylcoumarin) protects L. infantum cysteine proteinase from inactivation by SNAP. These results indicate that parasite cysteine proteinase inactivation by NO-donors occurs via NO-mediated S-nitrosylation of the Cys25 catalytic residue.

Animals↗

PubMed2004

Preparation and characterization of starch/cyclodextrin bioadhesive microspheres as platform for nasal administration of Gabexate Mesylate (Foy) in allergic rhinitis treatment.

Bioadhesive and biodegradable microspheres were obtained by chemical cross-linking with epichlorohydrin of an alkaline solution of a mixture of starch and alpha-, beta-, or gamma-cyclodextrin (CyD). Microspheres were characterized by scanning electron microscopy, swelling degree, and water retention. The percentage of the effective CyD in microspheres was estimated by measuring the amount of iodine and typical organic compounds (TOCs) retained in the hydrophobic cavity of CyD. Gabexate Mesylate (trade name Foy); GM), an antiallergic drug, was included in microspheres by soaking in an aqueous solution containing the drug, followed by solvent evaporation or lyophilization. UV, IR, and DSC data indicated that despite the fact that GM is a hydrophilic drug, its hydrophobic moiety close to the benzene ring is able to penetrate the CyD cavity and to form stable inclusion complexes. Values of the association equilibrium constant for GM binding to CyD, obtained by UV differential spectroscopy, indicated that the affinity of the drug for alpha- and gamma-CyD is higher than that for beta-CyD. In vitro, GM was gradually released during 1h. Even if the release rate of the drug is relatively fast, the microspheres might actually provide the best platform since the material adheres to the nasal mucosa which was proved by adhesion tests. The GM integrity was checked by comparing its anti-trypsin activity before and after release.

Adhesives↗

PubMed2003

Lipid-based supramolecular systems for topical application: a preformulatory study.

This article describes the production and characterization of monoglyceride-based supramolecular systems by a simple processing technique, avoiding time-consuming procedures, high energy input, and the use of organic solvents. A preformulatory study was performed to study the influence of the experimental parameters on the production of monoglyceride-based disperse systems. In particular the effects of (1) stirring speed, (2) type and concentration of monoglyceride mixture, and (3) type and concentration of surfactant were investigated on the recovery, fraction of larger particles, mean diameter, and shape of smaller particles (so called nanosomes). Dispersions were first characterized by optical microscopy and freeze-fracture electron microscopy. The mean diameter of standard nanosomes, analyzed by photon correlation spectroscopy (PCS) after elimination of larger particles by filtration, was 193.5 nm. Cryotransmission electron microscopy studies, conducted in order to investigate the structure of dispersions, showed the coexistence of vesicles and particles characterized by a cubic organization. X-ray diffraction data revealed the coexistence of 2 different cubic phases, the first being a bicontinuous cubic phase of spatial symmetry Im3m (Q229) and the second belonging to the Pn3m spatial symmetry. A study on the stability of monoglyceride-based dispersions based on macroscopical analysis of organoleptic properties and dimensional analysis by time was performed after elimination of larger particles by filtration. Organoleptic and morphological features do not change by time, appearing free from phase-separation phenomena for almost 1 year from production. PCS studies showed that nanosomes undergo an initial increase in mean diameter within the first month following production; afterwards they generally maintain their dimensions for the next 4 months.

Chemistry, Pharmaceutical↗

PubMed2003

Pullulan-cyclodextrin microspheres. A chromatographic approach for the evaluation of the drug-cyclodextrin interactions and the determination of the drug release profiles.

Pullulan microspheres containing cyclodextrin (CyD) were obtained by chemical crosslinking with epichlorohydrin of an alkaline solution of pullulan (Pul) and alpha-, beta- or gamma-CyD. The amount of alpha-, beta- and gamma-CyD in microspheres was 120, 156, and 138 micromol/g, respectively, as determined from the percentage of iodine incorporated in the hydrophobic cavity of CyD's. Microspheres were packed in a glass column and the liquid chromatographic behaviour by isocratic elution of different drugs or typical organic compounds (TOC), taken as model drugs, was investigated. The increase of the retention volume (V(R)) of each compound, depending on the interaction(s) between CyD's cavity and the considered molecule, is characterized by a broadening of the peaks. The interaction coefficient K, corresponding to the ratio between the V(R) value of each tested molecule on Pul-alpha-, Pul-beta- and Pul-gamma-CyD active stationary phase and the V(R) value of benzoic acid on St/maltodextrin neutral stationary phase, was determined. According to K values, the accurate prediction can be done on the potential drugs to be conditioned in suitable CyD cavity. Values of K allow to anticipate the release profiles of drugs considered.

Cyclodextrins↗

PubMed2003

The bovine basic pancreatic trypsin inhibitor (Kunitz inhibitor): a milestone protein.

The pancreatic Kunitz inhibitor, also known as aprotinin, bovine basic pancreatic trypsin inhibitor (BPTI), and trypsin-kallikrein inhibitor, is one of the most extensively studied globular proteins. It has proved to be a particularly attractive and powerful tool for studying protein conformation as well as molecular bases of protein/protein interaction(s) and (macro)molecular recognition. BPTI has a relatively broad specificity, inhibiting trypsin- as well as chymotrypsin- and elastase-like serine (pro)enzymes endowed with very different primary specificity. BPTI reacts rapidly with serine proteases to form stable complexes, but the enzyme: inhibitor complex formation may involve several intermediates corresponding to discrete reaction steps. Moreover, BPTI inhibits the nitric oxide synthase type-I and -II action and impairs K+ transport by Ca2+-activated K+ channels. Clinically, the use of BPTI in selected surgical interventions, such as cardiopulmonary surgery and orthotopic liver transplantation, is advised, as it significantly reduces hemorrhagic complications and thus blood-transfusion requirements. Here, the structural, inhibition, and bio-medical aspects of BPTI are reported.

Acute Disease↗

PubMed2002

Spray dried Eudragit microparticles as encapsulation devices for vitamin C.

The aim of the present paper was to study production of methacrylate microparticles for the delivery (administration) of ascorbic acid via the oral route. Vitamin C is an important antioxidant that may be involved in the reduction of the risk of certain types of cancer, such as colorectal cancer. As polymers different acrylic compounds were considered, namely Eudragit RL, L and RS. Spray-drying was used as preparation method of vitamin C/Eudragit microspheres. Microspheres were first characterized by size and morphology by scanning electron microscopy, then in vitro release kinetics by mean of dialysis method were studied. Although the produced microparticles were unable to slow down the release of the drug with respect to the free form of ascorbic acid, these microspheres showed a good morphology and size distribution that permit to propose them as candidate for the delivery of vitamin C as associated therapy in the treatment of colorectal cancer by oral route.

Antioxidants↗

PubMedDate not supplied

Diffusion of preservatives from topical dosage forms: a comparative study.

A study of the diffusion of parabens from topical formulations is presented here. In particular, four different topical formulations, namely, a water-in-oil emulsion, an oil-in-water emulsion, and two hydrophilic gels (Pemulen gel and Carbopol gel) were produced, containing a mixture of three common parabens, namely, methylparaben (MP), ethylparaben (EP), and propylparaben (PP). An analytical method based on liquid extraction, followed by reversed-phase HPLC for the quantitative determination of MP, EP, and PP, was developed. The method allowed good separation of paraben mixtures and high percentages of recovery (> than 97%). The diffusion kinetics of parabens from the produced formulations was determined by an in vitro system based on a Franz cell assembled with a synthetic membrane, followed by a reversed-phase HPLC analytical method. The comparative study demonstrated that, in the case of emulsions, diffusion coefficients are a function of the substituent of preservatives: the higher the solubility, the higher the diffusion of parabens. On the contrary, in the case of the hydrophilic gels, the higher the parabens solubility, the lower the diffusion coefficients. The method described here could represent a means of controlling the extent of diffusion of parabens from topical formulations in order to minimize percutaneous absorption and to control the availability of microbes.

Chromatography, High Pressure Liquid↗

PubMedDate not supplied

Ethosomes and liposomes as topical vehicles for azelaic acid: a preformulation study.

The basic properties and the in vitro release rate kinetics of azelaic acid (AA), alternatively vehiculated in different phospholipid-based vesicles such as ethosomes or liposomes, were investigated. Ethosomes were produced by a simple method based on addition of an aqueous phase to an ethanol solution (comprised between 20\% and 45%, v/v) of soy phosphatidyl choline (5%, w/w) and AA (0.2%, w/w) under mechanical stirring. Liposomes were obtained by the same composition in the absence of ethanol with the reverse-phase evaporation method. Vesicle size was measured by photon correlation spectroscopy (PCS), evidencing smaller mean diameters and narrower dimensional distributions in the case of ethosomes with respect to liposomes. In order to obtain homogeneously sized vesicles, both ethosomal and liposomal dispersions were extruded through polycarbonate membranes with pores of calibrated diameter (400 nm and 200 nm). Vesicle morphology was characterized by freeze-fracture scanning electron microscopy (SEM) showing the presence of unilamellar vesicles both in liposome- and in ethosome-based dispersions. Free energy measurements of the vesicle bilayers were conducted by differential scanning calorimetry (DSC). AA diffusion from ethosomal or liposomal dispersions and from ethosomes and liposomes incorporated in a viscous gel was investigated by a Franz cell assembled with synthetic membranes. The release rate was more rapid from ethosomal systems than from liposomal systems. In particular, ethosomes produced by the highest ethanol concentration released AA more rapidly, and the same trend was found using viscous forms.

Administration, Topical↗