Cinzia Anna Ventura

Lecithin microemulsions for the topical administration of ketoprofen: percutaneous adsorption through human skin and in vivo human skin tolerability

The potential application of highly biocompatible o/w microemulsions as topical drug carrier systems for the percutaneous delivery of anti-inflammatory drugs, i.e. ketoprofen, was investigated. Microemulsions were made up of triglycerides as oil phase, a mixture of lecithin and n-butanol as a surfactant/co-surfactant system and an aqueous solution as the external phase. To evaluate the percutaneous enhancing effect of oleic acid, this compound was used as a component of some o/w microemulsions. The topical carrier potentialities of lecithin-based o/w microemulsions were compared with respect to conventional formulations, i.e. a w/o emulsion, a o/w emulsion and a gel. Physicochemical characterisation of microemulsions was carried out by light scattering and zeta potential analyses. Microemulsions showed mean droplet size < 35 nm and a negative zeta potential, that is -39.5 mV for the oleic acid-lecithin microemulsion and -19.7 mV for the lecithin-based microemulsion. The percutaneous adsorption of the various topical formulations was evaluated through healthy adult human skin, which was obtained from abdominal reduction surgery. Ketoprofen-loaded microemulsions showed an enhanced permeation through human skin with respect to conventional formulations. No significant percutaneous enhancer effect was observed for ketoprofen-loaded oleic acid-lecithin microemulsions. The human skin tolerability of various microemulsion formulations was evaluated on human volunteers. Microemulsions showed a good human skin tolerability.

Anticancer activity of liposomal bergamot essential oil (BEO) on human neuroblastoma cells.

Citrus extracts, particularly bergamot essential oil (BEO) and its fractions, have been found to exhibit anticancer efficacy. However, the poor water solubility, low stability and limited bioavailability have prevented the use of BEO in cancer therapy. To overcome such drawbacks, we formulated BEO liposomes that improved the water solubility of the phytocomponents and increased their anticancer activity in vitro against human SH-SY5Y neuroblastoma cells. The results warrant further investigation of BEO liposomes for in vivo applications.

Preparation, characterization, molecular modeling and In vitro activity of paclitaxel–cyclodextrin complexes

Paclitaxel (PTX) was complexed with beta-cyclodextrin (1), 2,6-dimethyl-beta-cyclodextrin (2) and 2,3,6-trimethyl-beta-cyclodextrin (3). PTX-CYD complexes were characterized both at the solid and liquid states. Experimental findings are in agreement with molecular modeling analysis, which showed different PTX-CYD interaction as a function of macrocyle methylation. The complexation of PTX within the CYD cavity preserved its antitumoral activity.

Ultradeformable liposomes as multidrug carrier of resveratrol and 5-fluorouracil for their topical delivery.

Ultradeformable liposomes represent useful formulations able to increase the skin permeation of drug compounds. In this study, resveratrol- and 5-fluorouracil-loaded ultradeformable liposomes were investigated for the potential treatment of non-melanoma skin cancer. The in vitro anticancer activity of ultradeformable liposomes was tested on human skin cancer cells through viability-, cell cycle- and apoptosis-analysis. Furthermore, we tested the percutaneous permeation of ultradeformable liposomes using human stratum corneum and viable epidermis. The co-encapsulation of resveratrol and 5-fluorouracil (multi-drug carrier) in ultradeformable liposomes improved their anticancer activity on skin cancer cells as compared to both the free drug form and the single entrapped agents. These multi-drug ultradeformable liposomes arrest cell proliferation in G1/S, thus modifying the action of 5-fluorouracil and increasing the activity of resveratrol. This effect might depend on the ultradeformable liposomes, which may accumulate in deeper skin layers, thus generating a cutaneous depot from which resveratrol and 5-fluorouracil are gradually released. Resveratrol and 5-fluorouracil co-loaded ultradeformable liposomes could be a new nanomedicine for the treatment of squamous cell carcinoma, i.e., actinic keratosis, Bowens disease, and keratoacanthoma.

Polyethylenimine and chitosan carriers for the delivery of RNA interference effectors

Introduction: Manipulating gene activity represents a promising approach for the treatment of cancer and other diseases. The relatively recent discovery of RNA interference (RNAi) revolutionized therapeutic approaches in this field. RNA effectors can now be used to modify the activity of genes and theoretically control any biological process. Area covered: However, the clinical application of RNAi has been limited by the inefficient delivery of RNA. Challenges associated with the in vivo use of RNAi mediators, include rapid degradation, uptake by the reticular endothelial system and inefficient cellular internalization. To date, various strategies have been developed in order to overcome these pitfalls. Among these approaches, non-viral delivery systems have gained increasing popularity, as they are generally considered safer than their viral counterparts. Expert opinion: The use of cationic polymers, especially polyethylenimine and chitosan, for the in vivo delivery of doubled-stranded RNAs is discussed in this review.

Effects of external phase on D-cycloserine loaded W/O nanocapsules prepared by the interfacial polymerization method

Water in oil (W/O) polybutylcyanoacrylate nanocapsules containing D-cycloserine (D-CS) for intranasal delivery were prepared by the interfacial polymerization method. Different oils, as external phase, for the preparation of the initial W/O miniemulsions were used and their effect on mean size and other physico-chemical properties were evaluated by photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM) analysis. Two probes at different hydrophilicity were used to verify the internal aqueous nature of the core. Both miniemulsions and nanocapsules mean size and polydispersity index were influenced by the used external phase. Different entrapment efficiency were obtained for D-cycloserine-loaded nanocapsules correlated to the used oil [ranging from 39 to 51% encapsulation efficiency (E.E.)]. In vitro drug release showed an initial burst effect (ranging from 20 to 40%) followed by a slow release of D-CS for all preparations. This study demonstrated that many relevant physico-chemical and technological properties of polybutylcyanoacrylate nanocapsules prepared by interfacial polymerization of miniemulsions are significantly influenced by the external oil phase used.

Dexamethasone sodium phosphate-loaded Chitosan based delivery systems for buccal application

Chitosan (CH) was used as a biocompatible and bioadhesive polymer material to prepare solid dispersions as well as hydrogels loaded with dexamethasone sodium phosphate (DSP), a steroidal anti-inflammatory agent clinically used for treatment of different mouth diseases. Binary solid dispersions at various drug-to-polymer weight ratios were prepared by freeze-drying; their direct compression gave tablets which were characterized for the swelling behaviour and drug release in vitro. Similarly, DSP-loaded hydrogels composed of CH and glycerine were prepared and characterized. CH and DSP showed a good physical compatibility. A slow and prolonged release of the drug was observed in vitro from both kinds of systems. The swelling properties of the polymer seemed to be the main parameter affecting the drug release profile from both tablets and hydrogels at the pH value of mouth. In vivo buccal application of both the systems allowed to obtain a prolonged release of DSP, as compared with a glycerine solution of the drug. From the in vitro swelling studies and in vivo test, the 2:1 CH-DSP solid dispersion in particular can be designated for further investigation.

Biomembrane Model Interaction and Percutaneous Absorption of Papaverine Through rat Skin: Effects of Cyclodextrins as Penetration Enhancers

The effects of different concentrations of β-cyclodextrin (β-CyD), hydroxypropyl-β-cyclodextrin (HP-β-CyD) and 2,6-di-O-methyl-β-cyclodextrin (DM-β-CyD) on percutaneous absorption of papaverine hydrochloride (PAP) were investigated. Abdominal rat skin mounted in Franz cells was used for in vitro experiments. To evaluate CyD interaction with a bilayer structure model, dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and DPPC-Chol (8:2 mole ratio) vesicles were used. CyD vesicle interaction was evaluated by differential scanning calorimetry. Permeation through rat skin and calorimetric experiments demonstrated that at low concentrations DM-β-CyD shows higher enhancer activity as a possible result of a perturbing action on the skin by a complexation of its lipid components, but at higher concentrations HP-β-CyD is the most effective. By considering that HP-β-CyD presents a very moderate destabilizing action on the skin, we conclude that a 10% aqueous solution of this macrocycle appears to be the most suitable transdermal absorption enhancer for PAP.

Structural and spectroscopic features of lutein/butanoyl-β-cyclodextrin nanoassemblies.

Lutein, the primary carotenoid present in the central area of the retina of eye appears to be associated with the protection against age-related macular degeneration (the leading cause of blindness in older adults). Its lipophilicity and consequently its scarce water solubility (1.3×10(-9)M) represent a drawback for bioavailability. To circumvent these unfavorable characteristics, in this work lutein (Lut) have been encapsulated in amphiphilic cyclodextrin (ACyD) by following the well-established strategy of entrapping a lipophilic drug in CyD carriers. Primary face butyrate modified β-cyclodextrins (C(4:7)) form in water nanoaggregates with a average size of 250nm and a ζ-potential of about -6mV. They are able to entrap lutein at 1:6 Lut/ACyD molar ratio by yielding nanoassemblies of vesicular aspect (320nm and -8mV) such as observed by static, dynamic and electrophoretic light-scattering. UV-vis measurements revealed that electronic properties of lutein were maintained when interact with ACyD nanoaggregates. The monitoring of the entapped carotenoid leaking from ACyD nanostructures was investigated suggesting the potential of Lut/ACyD nanoassemblies in drug delivery.

Celecoxib-loaded PLGA/cyclodextrin microspheres: Characterization and evaluation of anti-inflammatory activity on human chondrocyte cultures

PLGA microspheres were prepared as a sustained release system for the intra-articular administration of celecoxib (CCB). The microspheres were prepared in the presence of different concentrations of dimethyl-β-cyclodextrin (DM-β-Cyd), by the simple oil-in-water emulsion/evaporation solvent method. The microspheres were evaluated as to surface morphology, size and technological properties (such as encapsulation efficiency, drug loading capacity and drug release). Ex vivo studies on cultures of human chondrocytes were performed in order to evaluate the influence of the polymeric carriers on the pharmacological activity of CCB. All systems ranged from about 1 to 5 μm in size and had a high encapsulation efficiency percentage ranging from about 80% to 90% (w/w), except for CCB-loaded-PLGA microspheres containing the highest amount of DM-β-Cyd, in which a dramatic drop in the encapsulation efficiency was observed (about 54%, w/w). FIB images evidenced the fact that the microspheres had a porous structure in the presence of the highest amount of DM-β-Cyd. The macrocycle modulated the release profiles of CCB from the microspheres, producing in some cases a zero-order kinetic release. Ex vivo biological studies demonstrated that DM-β-Cyd improved the drugs anti-inflammatory activity. Thus, CCB-loaded PLGA/cyclodextrin microspheres may have a potential therapeutic application in the treatment of osteo- and rheumatoid arthritis.