Search

Levofloxacin (LVF) is an antibacterial drug approved for the treatment of ocular infections. However, due to the low ocular bioavailability, high doses are needed, causing bacterial resistance. Polymeric nanospheres (NPs) loading antibiotic drugs represent the most promising approach to eradicate ocular infections and to treat pathogen resistance. In this study, we have developed chitosan NPs based on sulfobutyl-ether-β-cyclodextrin (CH/SBE-β-CD NPs) for ocular delivery of LVF. CH/SBE-β-CD NPs loading LVF were characterized in terms of encapsulation parameters, morphology, and sizes, in comparison to NPs produced without the macrocycle. Nuclear magnetic resonance and UV–vis spectroscopy studies demonstrated that SBE-β-CD is able to complex LVF and to influence encapsulation parameters of NPs, producing high encapsulation efficiency and LVF loading. The NPs were homogenous in size, with a hydrodynamic radius between 80 and 170 nm and positive zeta potential (ζ) values. This surface property could promote the interaction of NPs with the negatively charged ocular tissue, increasing their residence time and, consequently, LVF efficacy. In vitro, antibacterial activity against Gram-positive and Gram-negative bacteria showed a double higher activity of CH/SBE-β-CD NPs loading LVF compared to the free drug, suggesting that chitosan NPs based on SBE-β-CD could be a useful system for the treatment of ocular infections.

By exploiting the chemical versatility and the high water dispersibility of α,β-poly(N-2-hydroxyethyl)D,L-aspartamide, in this work, two different polymer derivatives were synthesized for the first time. Obtained macromolecules were characterized and used to produce hydrogels exploitable for the local release of hydrophobic anticancer drugs. The first derivative, bearing pendant β-cyclodextrins, was employed to solubilize tamoxifen, chosen as a model drug, and to produce a water soluble supramolecular complex, as evidenced through tamoxifen phase solubility studies. The second derivative, bearing pendant Cyclo(Arginine-Glyicine-Asparagine-D-Phenilyalanine-Cysteine) peptide moieties, was used as a macromolecular crosslinker to obtain a hydrogel with cellular recruitment properties. The occurrence of crosslinking between the two derivatives was studied through rheological analysis and different procedures were employed to obtain tamoxifen medicated hydrogels. In vitro release studies, together with cytotoxicity and recruitment experiments, reveal that the obtained hydrogels can control the release of anticancer drugs, have a cytotoxic effect on human breast carcinoma cells and, thanks to the presence of adhesion moieties, are able to recruit cancer cells.

A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on sulfobutylether-β-cyclodextrin (SBE-β-CD) as hosting agent and Coumestrol (7,12-dihydorxcoumestane, Coum), a poorly-soluble active compound known for its anti-viral and anti-oxidant activity. For this purpose, synchronous and asynchronous 2D spectra were calculated in three different wavenumber regions (960–1320 cm−1, 1580–1760 cm−1 and 2780–3750 cm−1) and over a temperature range between 250 K and 340 K. The resolution enhancement provided by the 2D-COS offers the possibility to extract the sequential order of events tracked by specific functional groups of the system, and allows, at the same time, the overcoming of some of the limits associated with conventional 1D FTIR-ATR analysis. Acquired information could be used, in principle, for the definition of an optimized procedure capable to provide high-performance T-sensitive drug carrier systems for different applications.

Linoleic and oleic acids are natural unsaturated fatty acids involved in several biological processes and recently studied as structural components of innovative nanovesicles. The use of natural components in the pharmaceutical field is receiving growing attention from the scientific world. The aim of this research work is to design, to perform physico-chemical characterization and in vitro/in vivo studies of unsaturated fatty acids vesicles containing ammonium glycyrrhizinate, obtaining a new topical drug delivery system. The chosen active substance is well known as an anti-inflammatory compound, but its antioxidant activity is also noteworthy. In this way, the obtained nanocarriers are totally natural vesicles and they have shown to have suitable physico-chemical features for topical administration. Moreover, the proposed nanocarriers have proven their ability to improve the in vitro percutaneous permeation and antioxidant activity of ammonium glycyrrhizinate on human keratinocytes (NCTC 2544 cells). In vivo studies, carried out on human volunteers, have demonstrated the biocompatibility of unsaturated fatty acid vesicles toward skin tissue, indicating a possible clinical application of unsaturated fatty acid vesicles for the treatment of topical diseases.

This study was aimed at preparing and characterizing solid lipid nanoparticles loading rutin (RT-SLNs) for the treatment of oxidative stress-induced diseases. Phospholipon 80H® as a solid lipid and Polysorbate 80 as surfactant were used for the SLNs preparation, using the solvent emulsification/diffusion method. We obtained spherical RT-SLNs with low sizes, ranging from 40 to 60 nm (hydrodynamic radius) for the SLNs prepared starting from 2% and 5% (w/w) theoretical amount. All prepared formulations showed negative zeta-potential values. RT was efficiently encapsulated within SLNs, obtaining high encapsulation efficiency and drug content percentages, particularly for SLNs prepared with a 5% theoretical amount of RT. In vitro release profiles and analysis of the obtained data applying different kinetic models revealed Fickian diffusion as the main mechanism of RT release from the SLNs. The morphology of RT-SLNs was characterized by scanning electron microscopy (SEM), whereas the interactions between RT and the lipid matrix were investigated by Raman spectroscopy, evidencing spectral modifications of characteristic bands of RT due to the establishment of new interactions. Finally, antioxidant activity assay on human glioblastoma astrocytoma (U373) culture cells showed a dose-dependent activity for RT-SLNs, particularly at the highest assayed dose (50 μM), whereas the free drug showed the lesser activity.

The ability of Captisol® (sulphobutylether-β-cyclodextrin, SBE-β-CD), to form inclusion complexes, both in solution and in the solid state, has been tested in order to improve some unfavorable chemical-physical characteristics, such as poor solubility in water, of a bioflavonoid, Coumestrol (Coum), well known for its anti-oxidant, anti-inflammatory, anti-fungal and anti-viral activity. In pure water, a phase-solubility study was carried out to evaluate the enhancement of the solubility of Coum and, therefore, the occurred complexation with the macrocycle. The stoichiometry and the stability constant of the SBE-β-CD/Coum complex were calculated with the phase solubility method and through the Job's plot. After that, the solid SBE-β-CD/Coum complex was prepared utilizing a kneading method. The spectral changes induced by complexation on characteristic vibrational band of Coum were complementary investigated by Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and Raman spectroscopy, putting into evidence the guest chemical groups involved in the “host-guest” interactions responsible of the formation and stabilization of the complex. Particular attention was paid to the C O and O H stretching vibrations, whose temperature-evolution respectively furnished the enthalpy changes associated to the binding of host and guest in solid phase and to the reorganization of the hydrogen bond scheme upon complexation. From the whole set of results, an inclusion geometry is also proposed.

In this paper, two medusa-like ACyDs, modified at the primary rim bearing four (ACyD4) and eight carbons (ACyD8) acyl chain length, and one bouquet-like CyD, modified at primary side with thiohexyl and at secondary one with oligoethylene moiety (SC6OH), were investigated for their ability to assemble in nanostructures or to form hybrid dipalmitoylphosphatidylcholine (DPPC)/ACyDs systems. The lipophilicity of these molecules and the different preparation methods used in this study (thin layer evaporation and nanoprecipitation method) significantly affect the aggregation behaviour in aqueous medium. Except for the shortest medusa-like ACyD4, the other ACyDs formed stable nanoaggregates for at least 45 days. The effect of ACyDs on the thermotropic behaviour of DPPC liposomes was also studied by differential scanning calorimetry analysis, thus elucidating their interaction with liposomes to afford hybrid liposome/ACyDs systems. The medusa-like ACyD4 cannot be used to realize nanosystems because it quickly aggregates or it induces a complete destabilization of the liposomes. At the highest concentration investigated (0.01 molar fraction), both ACyD8 and SC6OH interacted with DPPC liposomes, forming ACyD/DPPC or SC6OH/DPPC hybrid vesicular carriers.

Elastic incoherent neutron scattering was employed to investigate the molecular mobility of inclusion complexes, formed by two β-cyclodextrin (β-CD) derivatives, namely (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) and methyl-β-cyclodextrin (Me-β-CD), with Genistein (Gen), a phytoestrogen having antioxidant and anticarcinogenic activities, compared to the physical mixtures and single components. The results, collected in the 20–300 K temperature range, revealed a purely vibrational dynamics up to ∼100 K, where a first anharmonic contribution, corresponding to the methyl rotational dynamics, was observed and represented by an Arrhenius trend. At higher temperatures, a second anharmonic process, also found to obey an Arrhenius-like behavior, occurred at Td and was mainly ascribed to the relaxation of the H-bond network formed by host and guest molecules. Enthalpy and entropy changes associated to the activated anharmonic processes were obtained. The picoseconds timescale dynamics was finally connected to the thermal stability, suggesting HP-β-CD as the most effective carrier for Gen.

Poloxamer 407 copolymer is a versatile and widely used thermo-reversible material. Its use has many advantages, such as bio-adhesion, enhanced solubilization of poorly water-soluble drugs and many applications fields like oral, rectal, topical, nasal drug administration. Hydrogels made up of Poloxamer 407 are characterized by specific rheological features, which are affected by temperature, concentration and presence of other compounds. A strategic approach in topical therapeutic treatments may be the inclusion of drug delivery systems, such as ethosomes, transfersomes and niosomes, into hydrogel poloxamer formulation. The evaluation of the interaction between colloidal carriers and the Poloxamer 407 hydrogel network is essential for a suitable design of an innovative topical dosage form. For this reason, the Rheolaser Master&trade, based on diffusing wave spectroscopy, and a Kinexus Rotational Rheometer were used to evaluate the influence of nanocarriers on the microrheological features of hydrogels. The advantages of the Rheolaser Master&trade, analyzer are: (i) its ability to determine viscoelastic parameter, without altering or destroying the sample and at rest (zero shear), (ii) possibility of aging analysis on the same sample. This study provide evidence that vesicular systems do not influence the rheological features of the gel, supporting the possibility to encapsulate an innovative system into a three-dimensional network.

We investigated the complexation of celecoxib (CCB) into sulfobuthyl-ether-β-cyclodextrin (SBE-β-CD) for the realization of an inhalable dry-powder formulation containing gemcitabine (GEM) for lung anticancer therapy. Complexation increased the water solubility of CCB (0.003 mg/mL and 0.834 mg/mL for CCB free and complexed, respectively) and produced a quantitative dissolution of the drug within 15 min. The CCB/SBE-β-CD inclusion complex showed a high stability constant (8131 M–1) not influenced by the presence of GEM in solution. Two-dimensional NMR experiments and computational studies demonstrated that the pyrazole ring of CCB penetrates deeper into SBE-β-CD from the secondary rim. The aromatic rings are positioned at the edge of the cavity, establishing hydrogen bonds with the SBE-β-CD that stabilized the complex. CCB showed limited cytotoxic activity on A549 cell lines. Complexation significantly increased activity passing from 30% to 45% cell mortality. Moreover, CCB/SBE-β-CD strongly improved the cytotoxicity of GEM, observing about 60% of cell mortality for the combined formulation.

The ability of some surfactants to self-assemble in a water/oil bi-phase environment thus forming supramolecular structure leading to the formation of w/o/w multiple emulsions was investigated. The w/o/w multiple emulsions obtained by self-assembling (one-step preparation method) were compared with those prepared following the traditional two-step procedure. Methyl-nicotinate was used as a hydrophilic model drug. The formation of the multiple emulsion structure was evidenced by optical microscopy, which showed a mean size of the inner oil droplets of 6 μm and 10 μm for one-step and two-step multiple emulsions, respectively. The in vitrobiopharmaceutical features of the various w/o/w multiple emulsion formulations were evaluated by means of viscosimetry studies, drug release and in vitro percutaneous permeation experiments through human stratum corneum and viable epidermis membranes. The self-assembled multiple emulsions allowed a more gradual percutaneous permeation (a zero-order permeation rate) than the two-step ones. The in vivotopical carrier properties of the two different multiple emulsions were evaluated on healthy human volunteers by using the spectrophotometry of reflectance, an in vivonon invasive method. These multiple emulsion systems were also compared with conventional emulsion formulations. Our findings demonstrated that the multiple emulsions obtained by self-assembling were able to provide a more sustained drug delivery into the skin and hence a longer therapeutic action than two-step multiple emulsions and conventional emulsion formulations. Finally, our findings showed that the supramolecular micro-assembly of multiple emulsions was able to influence not only the biopharmaceutical characteristics but also the potential in vivotherapeutic response.

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, Bowen's disease, and keratoacanthoma.

Hydroxypropyl-β-cyclodextrin (HP-β-CyD) and sulfobutyl ether-β-cyclodextrin (SBE-β-CyD) were used to generate hydrophilic complexes of the poorly water-soluble drug testosterone propionate (TP). The inclusion complexes were obtained by freeze-drying, and then analyzed at both liquid and solid states. Phase solubility studies, performed according to the type-AL solubility diagrams of TP in presence of both CyDs, suggested the formation of water-soluble complexes at 1:1 molar ratio. These results were confirmed by continuous variation method (Job’s plot). Both CyDs increased water-solubility of TP 100-fold as compared to the native drug. The host-guest arrangement of CyD complexes in a water solution was further investigated by one- and two-dimensional NMR spectroscopy, highlighting the insertion of the tetracyclic ring of TP into the CyD cavity, and the interaction of the pending ester chain of drug with the primary hydroxyl groups of CyDs at the narrow end of the toroid structure. In solid phase, FTIR-ATR spectroscopy showed that the C O stretching mode of the TP vibrational spectrum changed if the complex between the drug and CyDs occurred. This change is temperature-dependent, and its evolution, accounted for by deconvolution procedures, provided the thermodynamic parameters explaining the mechanisms involved in the formation of inclusion complexes.

In order to obtain nanocarriers suitable for the delivery of drugs in the treatment of cancer, pH-responsive nanovesicles capable of facilitating fusion (fusogenic nanovesicles) were synthesized and then their physicochemical characteristics were modified. These nanovesicles were made by combining polysorbates having different physicochemical features with the aim of realizing multiple-targeting nanoformulations suitable for in vitro treatment of cancer cells. Tween21 and Tween80 were self-assembled at different molar concentrations resulting in pH-responsive fusogenic nanovesicles with an average size of less than 150 nm, and a narrow size distribution (polydispersity index) value of less than 0.2. Hydrophobic and hydrophilic fluorescent probes were loaded inside the nanovesicles in order to study their pH-responsiveness and fusogenic properties and it was noted that this process did not modify their physicochemical features. The pH-responsiveness and fusogenic assay demonstrated that the nanovesicles containing Tween21 at different molar ratios were pH-responsive and interacted with a synthetic model of a biological membrane supplemented with Ca2+ in the incubation medium. Fifty percent (molar ratio) of Tween21 was replaced with Tween80, since Tween80 can promote the adsorption of apolipoproteins (A–E) onto the surfaces of nanovesicles without altering their pH-responsiveness or fusogenic properties. In fact this equivalent molar concentration of Tween21 and Tween80 also maintained their degree of interaction with the apolipoproteins (A–E). Doxorubicin hydrochloride-loaded nanovesicles were synthesized and physicochemically characterized in order to obtain nanoformulations suitable for anticancer treatment. The therapeutic nanovesicles showed physicochemical properties similar to those of empty nanoformulations, and maintained pH-responsiveness, fusogenic properties and targeting versus the apolipoproteins (A–E). The doxorubicin hydrochloride was loaded into the nanovesicles using both passive and pH gradient remote loading procedures. The latter provided the nanovesicles with an entrapment efficiency percentage of over 30%, which was much higher than the 10% that was obtained using the passive loading procedure. The entrapment efficiency improved up to 60% for the nanovesicles made from the same molar concentration of Tween21 and Tween80. The anticancer activity of doxorubicin hydrochloride-loaded nanovesicles was further tested in vitro using human neuroblastoma (SH-SY5Y) cells which respond to treatment with this chemotherapeutic drug, but the nanovesicles carrying it must cross the BBB by means of specific receptors before the drug can provide a therapeutic effect in vivo. The anticancer activity of these doxorubicin hydrochloride-loaded nanovesicles was time- and dosage- dependent, and the surfactant components making up the nanoformulations was also a determining factor in the efficiency of their activity. These nanovesicles could provide innovative nanotherapeutics for potential in vitro multidrug targeting therapy.

Currently, six liposomal chemotherapeutics have received clinical approval and many more are in clinical trials or undergoing preclinical evaluation. Liposomes exhibit low toxicity and improve the biopharmaceutical features and therapeutic index of drugs, thereby increasing efficacy and reducing side effects. In this review we discuss the advantages of using liposomes for the delivery of chemotherapeutics. Gemcitabine and paclitaxel have been chosen as examples to illustrate how the performance of a metabolically unstable or poorly water-soluble drug can be greatly improved by liposomal incorporation. We look at the beneficial effects of liposomes in a variety of solid and blood-borne tumors, including thyroid cancer, pancreatic cancer, breast cancer and multiple myeloma.

A vibrational study by means of UV-Raman and FTIR-ATR measurements has been performed on sulfobutyl ether β-cyclodextrin (SBE-β-CD)-water solutions, as a function of concentration and temperature, with the aim to provide a molecular-scale explanation of the enhanced performances as carrier agent exhibited by this modified macrocycle with respect to natural cyclodextrin. The attention has been mainly paid to the modifications induced on the vibrational band assigned to the O-H stretching intramolecular mode, in turn related to the dynamical rearrangement occurring in the hydrogen bonding (HB) network of water molecules. The results of our measurements clearly showed a characteristic "structure-breaker" effect on the tetrahedral HB arrangements induced on water molecules by increasing of both temperature and solute concentration, allowing us to also extract thermodynamic parameters. These results could be a key step for a clearer understanding of the connection between the dynamical properties of hydration water and the complexing ability of this cyclodextrin derivative.

The science innovations improved the patient quality of life and perspectives. In particular, the revolutionary turmoil of the second half of twentieth century in the Science Academia poses the milestone to develop innovative supramolecular nanotherapeutics and enforce nanotechnology and drug delivery. The driving force of this revolution was the synthesis of novel, safe and biocompatible nanomaterials, which can be easily combined to design new supramolecular nanotherapeutics. Additionally, these innovative nanomaterials can, per se or as supramolecular nanocarriers, deliver bioactive compounds, which show different physical-chemical features, and treat different diseases. Recently, pharmaceutical industry and academia show a specific interest for natural products, which emerge as potential new drug candidates for the therapeutic treatment of inflammatory pathologies. In fact, the delivery of natural products by using supramolecular nanotherapeutics can represent a great opportunity in nanomedicine and an alternative therapeutic option to conventional medicine for treating inflammatory diseases. In this review, we will discuss the recent innovation of supramolecular nanotherapeutics delivering natural anti-inflammatory compounds and provide an overview of their application in nanomedicine.

This study investigates the potential of chitosan microspheres as delivery systems for the anticancer drug gemcitabine. The microspheres were obtained by spray-drying chitosan-gemcitabine solutions containing different amounts of the polyanion dextran sulphate. Morphological characterization by SEM and FIB analyses showed the presence of porous spherical particles having sizes ranging from about 1 to 5 μm. Dextran sulphate improves the technological parameters of the systems by producing very high encapsulation efficiency (about 96%, w/w) and by influencing the in vitro release of gemcitabine. The immediate drug release observed in the system prepared without dextrane sulphate (complete drug release within 30 min) was somewhat reduced by the polyanion (immediate release of 70% (w/w) of the encapsulated drug within 30 min, and subsequent continued release of the remaining 30% of the drug for over 4 days). The anti-tumoral efficacy of the various formulations was tested in vitro on human lung cancer cells (A549) comparing the effects with those of the free drug or drug/dextran sulfate complex. The carriers improved the cytotoxic activity of the drug, particularly the formulation containing the lowest amount of dextran sulphate after 72 h incubation.

We report the synthesis of an oligomeric prodrug of the antiviral agent Acyclovir (Acy) conjugated to β-cyclodextrin (β-CyD). The drug was selectively linked through a succinic spacer to one of the primary hydroxyl groups of β-CyD by ester linkage in a 1:1 molar ratio. The conjugate was purified by semipreparative reverse-phase chromatography and characterized by FAB mass spectrometry and NMR experiments. The release of Acy from the conjugate was evaluated both in acidic and in neutral conditions and in the presence of porcine liver esterase. In all cases we observed the release of both free Acy and Acy succinate (AcySucc) at differing rates as a function of the hydrolysis conditions. In the presence of esterase the release of free Acy was favoured over AcySucc, showing a release rate of 100% of Acy within 7 days.

The effect of a polyanionic variably substituted sulfobutyl ether-β-cyclodextrin (SBE-β-CyD), complexation on the UV absorption of genistein (Gen) and daidzein (Dai) was studied in pure water. A phase solubility study was performed, according to the method reported by Higuchi and Connors, to evaluate the changes of isoflavones in the complexation state and type-AL solubility diagrams for both isoflavones were obtained suggesting that they form complexes with 1:1 molar ratio. These results were confirmed by Job’s plot method. Complexation strongly increases the water solubility of isoflavones. The in vitro dissolution of isoflavones entrapped into SBE-β-CyD significantly surpassed that of the free isoflavones (over 90 % of the loaded Gen and Dai dissolved in 15 and 30 min, respectively). Finally, 1:1 molar ratio solid complexes were prepared by the kneading method and characterized in solid state by FTIR-ATR spectroscopy, with particular regard to O–H and C=O stretching vibrations, achieving structural information on the modifications induced by complexation on the H-bond scheme, also by applying band decomposition and curve-fit.

A resveratrol/sulfobutylether-β-cyclodextrin inclusion complex was prepared using the freeze-drying method and characterized in solution through UV-vis spectroscopy, solubility phase studies and Job's plot methods. At the solid state it was characterized using the FTIR-ATR technique. Sulfobutylether-β-cyclodextrin has a high affinity for the drug, and forms an inclusion complex with a 1:1 molar ratio both in solution and as a solid sample. It also has a high stability constant (Kc, 10,114 M(-1)). Complexation strongly increases the water solubility of resveratrol (from 0.03 mg/ml to 1.1 mg/ml, at 25 °C) and positively influences its in vitro anticancer activity which was observed on a human breast cancer cell line (MCF-7). In solid phase, FTIR-ATR revealed itself as being a useful technique in elucidating the complexation mechanism, which it did by emphasizing the functional groups involved in the activation of non-covalent "host-guest" interactions.

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 drug's anti-inflammatory activity. Thus, CCB-loaded PLGA/cyclodextrin microspheres may have a potential therapeutic application in the treatment of osteo- and rheumatoid arthritis.

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 ...

The favourable accessibility offered by sulfobutyl ether β-cyclodextrin (SBE-β-CD) for the complexation with idebenone (IDE) has been probed, as a function of temperature, in liquid state, by phase solubility study, and, in solid state, by FTIR-ATR technique. The phase solubility results indicated the formation of a IDE/SBE-β-CD inclusion complex with 1:1 molar ratio (AL type diagram), whose apparent stability constants at T = 300, 310, and 320 K have been estimated according to the Higuchi–Connors method. The formation of the inclusion complex has been confirmed on a freeze-dried and a co-precipitated product by FTIR-ATR spectroscopy, monitoring the changes induced by complexation on some characteristic vibrational bands of IDE. Quantitative studies, performed in a wide T range, from T = 250 K to T = 340 K, allowed us to extract information on the effect of temperature on the different hydrogen-bonded environments involving host, guest, and crystallization water molecules. Again, complexation is proved to enhance the stability of the guest, at least in the explored T range.

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 (C4:7) form in water nanoaggregates with a average size of 250 nm and a ζ-potential of about −6 mV. They are able to entrap lutein at 1:6 Lut/ACyD molar ratio by yielding nanoassemblies of vesicular aspect (320 nm and −8 mV) 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. 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 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 ) 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.

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.

Multilamellar liposomes loaded with D-cycloserine (D-CS) were prepared by a thin layer evaporation technique, followed by freezing and thawing cycles. Charged components and bioadhesive material, such as distearolylphosphatitylethanolamine covalently coupled with methoxypolyethyleneglycol, were used to prepare liposomes with different physico-chemical and technological properties. Negatively charged liposomes showed higher D-CS encapsulation efficiency (about 37%, w/w) than neutral and positively charged liposomes (about 5 and 17%, w/w, respectively). All formulations showed in vitro, after a burst effect, a prolonged release of the encapsulated drug. Lipid vesicles made of dipalmitoylphosphatidylcholine (DPPC) were used as a biomembrane model to evaluate in vitro the interaction of D-CS with biological membranes. Differential scanning calorimetry was used as a simple and noninvasive technique of analysis. D-CS was distributed in the aqueous compartments of liposomes for interaction with the phospholipid polar head-groups (enhancement of Delta H value). However, due to its high diffusibility the drug was also able to freely permeate through DPPC liposomes, altering during this passage the hydrophobic domains of the bilayers. Stability studies were performed at different temperatures and pH values to assay the integrity of the drug during the liposome production steps. D-CS was rapidly degraded at acidic pH, but no significant hydrolysis was observed at pH 7.4 after 7 days.

Anaplastic thyroid carcinoma is one of the most aggressive and lethal solid carcinomas affecting humans. A major limit of the chemotherapeutic agents is represented by their low therapeutic index. In this work, we investigated the possibility of improving the anti-tumoral activity of gemcitabine by using pegylated unilamellar liposomes. Liposomes were made up of 1,2-dipalmitoyl-sn-glycero-3-phospocholine monohydrate/cholesterol/N-(carbonyl-methoxypolyethylene glycol-2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (6:3:1 molar ratio) and they were prepared with a pH gradient to improve the gemcitabine loading capacity. The anti-tumoral efficacy of the liposomal formulation was tested in vitro on human anaplastic thyroid carcinoma cells (ARO) in culture, comparing the effects with those of the free drug. Gemcitabine-loaded unilamellar liposomes had a mean size ∼200 nm with a zeta potential ∼–2mV. The liposomal carrier noticeably improved the anti-tumoral activity of gemcitabine against ARO cells in terms of both dose-dependent cytotoxic effect and of drug exposition effect. Namely, gemcitabine-loaded liposomes showed a cytotoxic effect (58.2% increase of cell mortality at 1 μM with respect to free drug) after 12 h incubation, while the free drug showed a significant activity only after 72 h incubation. Moreover, a significant effect on the cell mortality appeared at 0.1 μM and 100% mortality was detected at a concentration of 1 μM of gemcitabine-loaded liposomes, while the free drug elicited the same effect at a concentration of 100 μM. The improved anti-tumoral activity of gemcitabine determined by the liposomal carrier was due to a greater intracellular uptake. The intracellular gemcitabine levels as a function of time showed a sinusoidal profile with peaks after 2 h, 6 h and 11 h, related to the cellular cycle of ARO. PARP cleavage and DNA fragmentation analysis provided clear evidence of the apoptosis induction in ARO cells by treatment with liposomally entrapped gemcitabine after 72 h incubation. Thus, gemcitabine-loaded liposomes may have a potential therapeutic relevance for the treatment of anaplastic thyroid carcinoma.

Chitosan microspheres loaded moxifloxacin were prepared to obtain sustained release of the drug after intrapulmonary administration. The microspheres were produced by the spray-drying method using glutaraldehyde as the crosslinking agent. The particles were spherical with a smooth but distorted surface morphology and were of small size, ranging from 2.5 to 6.0microm, thus suitable for inhalation. In vitro release studies showed a significant burst effect for all crosslinked systems, followed by a prolonged moxifloxacin release, particularly in the presence of the highest glutaraldehyde concentration. Lipid vesicles made of dipalmitoylphosphatidylcholine (DPPC) were used as an in vitro biomembrane model to evaluate the influence of chitosan microspheres on the interaction of moxifloxacin with biological membranes. Differential scanning calorimetry was used as a simple and non-invasive technique of analysis. Moxifloxacin freely permeates through DPPC liposomes, interacting with the hydrophobic zone of the bilayers (lowering of the DeltaH value and loss of the cooperativity of the main transition peak). Uncrosslinked microspheres rapidly swelled and dissolved releasing free chitosan that was able to interact with liposomes (increase of DeltaH value), probably altering the biomembrane permeability to the drug. Crosslinked microspheres did not show this property. Pulmonary absorption of moxifloxacin-loaded chitosan microspheres was evaluated compared to the free drug. A monolayer of Calu-3 human bronchial epithelial cells mounted on Franz diffusion cells was used as an in vitro bronchial epithelium model. Microspheres retard the absorption of moxifloxacin and within 6h the cumulative amount of permeated drug was about 18%, 11% and 7% (w/w) for free moxifloxacin, moxifloxacin-loaded crosslinked and moxifloxacin-loaded uncrosslinked microspheres, respectively.

Quercetin-3-O-acyl esters (I-VI) were synthesized and their usefulness as quercetin topical prodrugs was evaluated. Quercetin esters were assayed to determine their water stability and solubility, their susceptibility to undergoing enzymatic hydrolysis and their permeation through excised human skin. Quercetin ethyl (I) and hexyl (IV) esters proved poorly stable in aqueous media and they were not assayed further. Among the derivatives tested, quercetin propyl (II) and butyl (III) esters were more water-soluble than the parent drug. Esters II, III and V were readily hydrolyzed by human plasma and esters II and III penetrated excised human skin better than quercetin from aqueous saturated solutions. On the basis of the results obtained, esters II and III could be regarded as promising quercetin topical prodrugs.

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.

In this work we evaluated the ability of 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-Cyd) to include the anti-rhinovirus drug Disoxaril (WIN 51711), increasing its water solubility and stability. The complex, prepared by kneading method, was characterized in the solid state by differential scanning calorimetry and in aqueous solution using circular dichroism and NMR spectroscopy. The formation of 1:1 and 1:2 drug-Cyd complexes was hypothesized. Stability constants for both complexes were determined on the basis of an Ap-type phase solubility diagrams and evidenced a very high stability for the 1:1 complex. Thermodynamic parameters of the binding process showed the existence of classical hydrophobic interactions in the 1:1 complex with the formation of a less ordered system after complexation. An enthalpic contribution rather than an entropic one accompanied the association of the second Cyd molecule. DM-beta-Cyd was able to significantly increase water solubility of WIN 51711, from 0.000123 to 0.47142 mg/ml. Free drug shows a very low water stability, it is completely hydrolyzed after 36 h in PBS (pH 7.0), at 4 degrees C. In the presence of DM-beta-Cyd only a 10% of WIN 51711 was degraded, to the same conditions, after 12 days. DM-beta-Cyd increases the permeation of WIN 51711 across excised bovine nasal mucosa mounted on Franz cells, with respect to the free drug. Nevertheless, the permeation process had a lag time of 2 h so that the drug might assure its pharmacological activity on the outer surface of the mucosa. In vivo studies on rabbits evidenced that WIN 51711 is well tolerated, having no observable effect on the nasal mucosa following repeated administration.

The preparation and technological characterization of nanosphere formulations (NS) containing the anticancer drug paclitaxel (PTX) are reported. Poly(lactide) (PLA) and poly(lactide-co-glycolide) (PLGA) nanospheres (NS) were prepared by a solvent displacement method. They showed a mean particle size in the range 150–300 nm, with a high homogeneity (polydispersity index in vitro drug release and biological activity on the human anaplastic thyroid carcinoma cell line 8305C. The PLGA NS, in particular, showed a cell growth inhibitory activity comparable to the free drug.

We evaluated the ability of two modified cyclodextrins, hydroxypropyl-beta-cyclodextrin (HP-beta-Cyd) and 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-Cyd), to influence the percutaneous absorption through isolated human stratum corneum and epidermis (SCE) of celecoxib (CCB). Previous studies demonstrated that DM-beta-Cyd includes the drug, producing a significant increase of water solubility (0.5 mg/ml at 25 degrees C) and dissolution rate of CCB. In this work chemical-physical characterization studies were performed to evaluate the ability of HP-beta-Cyd to include CCB. We showed that only an external interaction could exist between CCB and HP-beta-Cyd that positively influences the water solubility of the drug (0.12 mg/ml at 25 degrees C for CCB-HP-beta-CyD system and 4.12 x 10(-3) mg/ml at 25 degrees C for free CCB). In vitro percutaneous experiments were performed using samples in solution and in suspension containing different Cyd concentrations. Both HP-beta-Cyd and DM-beta-Cyd enhanced drug flux through SCE by means of an increase of dissolution rate of the drug as well as a direct action on the stratum corneum (SC). Histological analysis of treated SCE showed a protective effect of the two Cyds towards an invasive action shown by CCB on SC.

Conjugation with lipoamino acids (LAAs) increases the lipophilicity of drug molecules. Because of their amphipatic nature, they also provide the conjugated drugs a 'membrane-like character', capable to facilitate their interaction with and penetration through cell membranes and biological barriers. To study such a feature, our aim is to collect experimental and computational data using a novel series of lipophilic conjugates between a model drug (tranylcypromine (TCP)) and LAA residues containing a short, a medium or a long alkyl side chain (C-4 to C-16), to provide a wide range of lipophilicity. For comparison, a corresponding set of amides of TCP with alkanoic or fatty acids was prepared and characterized. Their in vitro monoamine oxidase inhibitory activity also tested.