Revistas
Revista:
COLLOIDS AND INTERFACE SCIENCE COMMUNICATIONS
ISSN:
2215-0382
Año:
2023
Vol.:
57
N°:
100747
TiO2 nanoparticles (NPs) have been modified with ß-cyclodextrin (ßCD)-food preservative complexes. The susceptibility of Escherichia coli and Staphylococcus aureus to TiO2 NPs, sorbic acid (SA), benzoic acid (BA), and
ß-Cyclodextrin-TiO2 NPs including SA or BA, was studied. At 0.5 mg mL¿1 TiO2 NPs were more effective in the
inhibition of bacterial growth than modified-TiO2 NPs, achieving 71% inhibition rate. At the higher concentration of 3 mg mL¿ 1 there were no significant differences between treatments, being all of them highly effective
reaching 90% inhibition. Higher treatment-doses were related to slower growth rates. Flow cytometry findings
suggested efficient NPs interaction with bacteria, being more noticeable in the case of TiO2 NPs. Regarding the
photocatalytic activity, under 0.600 mW cm¿ 2 irradiation, TiO2 NPs reached 95% methylene-blue dye degradation after 150 min, while ßCD-TiO2 NPs showed 3-times lower kinetic constant. Overall results suggest potential application of the new systems in active packages to protect food from microbial spoilage.
Revista:
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
ISSN:
1422-0067
Año:
2022
Vol.:
23
N°:
24
Págs.:
16119
Gemfibrozil (GEM) is a hypolipidemic agent, which is effective in reducing serum cholesterol and triglyceride levels. Complexation of GEM with native ß-cyclodextrin (ß-CD) and with the derivatives hydroxypropyl-ß- and randomly methylated ß-CD (HPß-CD and Meß-CD) was studied in aqueous solution of pH 2.8 and 7.0. The stability constants were determined by spectrofluorimetry, 1H-NMR spectroscopy and solubility assays. Considering the well-known difficulties to obtain similar stability constants by different techniques, the agreement of the values obtained supports the reliability of the results presented. The advantages and drawbacks of each analytical technique for the study of inclusion complexation were discussed as well. In addition, the thermodynamic parameters of complexation, enthalpy (¿H) and entropy (¿S), were determined and related to the type of molecular interactions that take place between GEM and the different cyclodextrins. Finally, solid dispersions were prepared by co-evaporation, kneading, vacuum desiccation, and coprecipitation, and complexation was evaluated by X-ray diffraction.
Revista:
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
ISSN:
0141-8130
Año:
2022
Vol.:
216
Págs.:
347 - 360
Polylactic acid (PLA) and cellulose acetate (CA) as biodegradable polymers are being highly exploited in the development of innovative materials across several industrial sectors. PLA and CA composite films with TiO2 nanoparticles (NPs) and beta-cyclodextrin grafted TiO2 NPs were prepared. Thermo- and photo-degradation studies were performed on PLA and CA films and noticed that higher amount of TiO2 induce greater color variations, structure modifications and weight losses. It has been observed 9.3 % and 5.1 % maximum weight loss for 5 % TiO2 CA and PLA matrices, respectively. beta CD-modified TiO2 NPs increased the photo-degradation of the plain polymers to a lesser extent than TiO2 NPs. Benzoic acid (BA) and sorbic acid (SA) were incorporated to beta CD-TiO2 NPs and the antibacterial activity of PLA and CA composite films was studied by inactivation of Escherichia coli and Staphylococcus aureus. CA film filled with 5 % TiO2 NPs presented the highest antibacterial activity and achieved 71 % inhibition of E. coli and 88 % inhibition of S. aureus. CA composite films showed potential to be used as antimicrobial food packaging.
Revista:
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
ISSN:
1422-0067
Año:
2021
Vol.:
22
N°:
5
Págs.:
2257
Polymeric materials, such as polyvinyl alcohol (PVA) and ethylene-PVA copolymers (EVOH) are widely used in the food sector as packaging materials because of their excellent properties. TiO2 nanoparticles (NPs) show photocatalytic activity; when added to the aforementioned polymers, on the one hand, they are expected to provide bactericidal capacity, whereas on the other hand, they could favor nanocomposite degradation. These types of nanoparticles can be derivatized with cyclodextrin macromolecules (CDs), which can act as food preservative carriers, increasing the packaging food protective properties. In this work, films containing beta-Cyclodextrin (beta CD)-grafted TiO2 nanoparticles and PVA or EVOH were prepared. Regarding the photocatalytic activity of the nanoparticles and the possible environmental protection, accelerated aging tests for PVA, EVOH, and their composites with cyclodextrin-grafted TiO2 nanoparticle (NP) films were performed by two methods, namely, stability chamber experiments at different conditions of temperature and relative humidity and UV light irradiation at different intensities. After analyzing the systems color changes (CIELAB) and Fourier transform infrared spectroscopy (FTIR) spectra, it was observed that the film degradation became more evident when increasing the temperature (25-80 degrees C) and relative humidity percentage (28-80%). There was no significant influence of the presence of CDs during the degradation process. When irradiating the films with UV light, the largest color variation was observed in the nanocomposite films, as expected. Moreover, the color change was more relevant with increasing NP percentages (1-5%) due to the high photocatalytic activity of TiO2. In addition, films were characterized by FTIR spectroscopy and variation in the signal intensities was observed, suggesting the increase of the material degradation in the presence of TiO2 NPs.
Revista:
JOURNAL OF VISUALIZED EXPERIMENTS
ISSN:
1940-087X
Año:
2020
Vol.:
155
N°:
e59636
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2020
Vol.:
588
Págs.:
119664
Photocatalytic properties of titanium dioxide nanoparticles (TiO2 NPs) have encouraged their use as fillers in polymer-based nanocomposites for application in food packaging. The surface modification of TiO2 NPs with cyclodextrins (CDs) can improve their functionality in a large extent. With this purpose, sorbic acid (SA) and benzoic acid (BA), commonly used as antifungal and antibacterial food preservatives, respectively, have been encapsulated in CD-grafted NPs. Inclusion complex formation of SA and BA with a and beta CDs in water has been assessed first by means of H-1 NMR and UV-Vis spectroscopy to determine the affinity of the preservatives for the macrocycles and the stoichiometry of the complexes. The association constants of both preservatives were found to be lower for beta CD, however, the loading efficiency in beta CD-grafted NPs was higher than that exhibited by alpha CD-NPs. Release kinetics from the CD-grafted NPs have been carried out. In the case of SA, the alpha CD-grafted NPs showed a prolonged and sustained release profile, suggesting its application as microbial growth inhibition system if incorporated into packaging materials.
Autores:
Carbajo-Gordillo, A. I.; Rodriguez-Lavado, J.; Jiménez-Blanco, J. L.; et al.
Revista:
CHEMICAL COMMUNICATIONS
ISSN:
1359-7345
Año:
2019
Vol.:
55
Págs.:
8227 - 8230
An original family of multivalent vectors encompassing gemini and facial amphiphilicity, namely cationic Siamese twin surfactants, has been prepared fromthe disaccharide trehalose; molecular engineering lets us modulate the self-assembling properties and the topology of the nanocomplexes with plasmid DNA for efficient gene delivery in vitro and in vivo.
Autores:
Rochin-Wong, S.; Rosas-Durazo, A. ; Zavala-Rivera, P. ; et al.
Revista:
POLYMERS
ISSN:
2073-4360
Año:
2018
Vol.:
10
N°:
7
Págs.:
760
Engineering of multifunctional drug nanocarriers combining stability and good release properties remains a great challenge. In this work, natural polymers kappa-carrageenan (kappa-CAR) and chitosan (CS) were deposited onto olive oil nanoemulsion droplets (NE) via layer-by-layer (LbL) self-assembly to study the release mechanisms of the anti-inflammatory diflunisal (DF) as a lipophilic drug model. The nano-systems were characterized by dynamic light scattering (DLS), zeta potential (zeta-potential) measurements, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (XEDS) and Fourier transform infrared spectroscopy (FTIR) to confirm the NE-coating with polymer layers. In addition, kinetic release studies of DF were developed by the dialysis diffusion bag technique. Mathematical models were applied to investigate the release mechanisms. The results showed that stable and suitably sized nanocapsules (similar to 300 nm) were formed. Also, the consecutive adsorption of polyelectrolytes by charge reversal was evidenced. More interestingly, the drug release mechanism varied depending on the number of layers deposited. The nanosized systems containing up to two layers showed anomalous transport and first order kinetics. Formulations with three and four layers exhibited Case II transport releasing diflunisal with zero order kinetics.
Revista:
CARBOHYDRATE POLYMERS
ISSN:
0144-8617
Año:
2018
Vol.:
195
Págs.:
476 - 485
The freezing-thawing is an advantageous method to produce hydrogels without crosslinking agents. In this study chitosan-poly(vinyl alcohol) (CS-PVA) hydrogels were prepared by varying the freezing conditions and composition, which affect the final characteristics of the products. The swelling degree, morphology, porosity, and diflunisal drug loading, as well as the drug release profiles were evaluated. The hydrogel swelling ratio was found to be mainly affected by the CS content, the number of freezing cycles and the temperature. SEM micrographs and porosity data confirm that pore size increases with the chitosan content. However, the use of either lower temperatures or longer freezing times, results in higher porosity and smaller pores. The drug release times of the CS-PVA hydrogels were as long as 30 h, and according to the mathematical fitting, a simple diffusion mechanism dominates the process. Moreover, a mathematical model predicting the hydrogels physical and structural behavior is proposed.
Revista:
CHEMISTRY-A EUROPEAN JOURNAL
ISSN:
0947-6539
Año:
2018
Vol.:
24
N°:
15
Págs.:
3825 - 3835
Engineering self-assembled superstructures through complexation of plasmid DNA (pDNA) and single-isomer nanometric size macromolecules (molecular nanoparticles) is a promising strategy for gene delivery. Notably, the functionality and overall architecture of the vector can be precisely molded at the atomic level by chemical tailoring, thereby enabling unprecedented opportunities for structure/self-assembling/pDNA delivery relationship studies. Beyond this notion, by judiciously preorganizing the functional elements in cyclodextrin (CD)-based molecular nanoparticles through covalent dimerization, here we demonstrate that the morphology of the resulting nanocomplexes (CDplexes) can be tuned, from spherical to ellipsoidal, rod-type, or worm-like nanoparticles, which makes it possible to gain understanding of their shape-dependent transfection properties. The experimental findings are in agreement with a shift from chelate to cross-linking interactions on going from primary-face- to secondary-face-linked CD dimers, the pDNA partner acting as an active payload and as a template. Most interestingly, the transfection efficiency in different cells was shown to be differently impacted by modifications of the CDplex morphology, which has led to the identification of an optimal prototype for tissue-selective DNA delivery to the spleen in vivo.
Autores:
Gonzalez, E. A. S.; Olmos, D. (Autor de correspondencia); Lorente, M. A. ; et al.
Revista:
POLYMERS
ISSN:
2073-4360
Año:
2018
Vol.:
10
N°:
12
Págs.:
1365
Polymer composite materials based on polylactic acid (PLA) filled with titanium dioxide (TiO2) nanoparticles were prepared. The aim of this work was to investigate the antibacterial action of TiO2 against a strain of E. coli (DH5) to obtain information on their potential uses in food and agro-alimentary industry. PLA/TiO2 systems were prepared by a two-step process: Solvent casting followed by a hot-pressing step. Characterization was done as a function of particle size (21 nm and <100 nm) and particle content (0%, 1%, 5%, 10%, and 20%, wt %). Structural characterization carried out by X-ray diffraction (XRD) and Fourier Transformed Infrared spectroscopy (FTIR) did not reveal significant changes in polymer structure due to the presence of TiO2 nanoparticles. Thermal characterization indicated that thermal transitions, measured by differential scanning calorimetry (DSC), did not vary, irrespective of size or content, whereas thermogravimetric analysis (TGA) revealed a slight increase in the temperature of degradation with particle content. Bacterial growth and biofilm formation on the surface of the composites against DH5 Escherichia coli was studied. Results suggested that the presence of TiO2 nanoparticles decreases the amount of extracellular polymeric substance (EPS) and limits bacterial growth.
Revista:
CURRENT PHARMACEUTICAL DESIGN
ISSN:
1381-6128
Año:
2017
Vol.:
23
N°:
3
Págs.:
411 - 432
The pharmaceutical applications of cyclodextrins (CDs), cyclic oligosaccharides capable of including hydrophobic molecules inside their cavities, have been known for decades. Besides the solubilising and encapsulating abilities of natural and modified CDs due to the formation of inclusion complexes, there is an increasing interest in organized macrostructures based on CDs as potential drug delivery devices and gene carrier systems. The present review discusses first the case of drug carriers based on monomeric modified CDs (amphiphilic and CD core-star polymers), in which self-assembly plays a major role. Polyrotaxanes, i.e., CDs threaded onto a polymer chain, are then reviewed in relation to their pharmaceutical applications. Finally, covalently linked CDs, either by grafting or crosslinking, are analyzed, including more complex structures formed by assembling CD-containing networks or chains. We have tried along this review to cover the most recent developments on these structures for drug delivery in a "beyond the cyclodextrin" approach. The review will be helpful, both for readers who want to be introduced into the world of these remarkable structures, or for specialists who are doing research in this field.
Revista:
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN:
1388-3127
Año:
2016
Vol.:
86
N°:
3 - 4
Págs.:
283 - 289
Cyclodextrin (CD) hydrogels were synthesized by a crosslinking reaction with the same cyclodextrin/epichlorohydrin mole ratio (1/11) using alphaCD, ßCD, gammaCD, and 50:50 mixtures of alpha/ßCD and ß/gammaCD. In order to investigate the sorption capacity of these hydrogels to different solutes, five model molecules have been selected: phenol, 3-nitrophenol, 4-nitrophenol, 1-naphthol, and the antiinflamatory drug diflunisal. The amounts sorbed have been related to the different affinities of the solutes. 1-naphthol shows the highest affinity for these polymers, especially in the case of sorbents containing ßCD. The sorption is considerably poorer for phenol than for its nitro derivatives. The two structural isomers 3- and 4-nitrophenol show significant differences in their affinities towards alphaCD, ßCD and alpha/ßCD. Finally, in the case of diflunisal, a bulkier model molecule, remarkable differences were found on the sorption behaviour by polymers whose cyclodextrins have a similar affinity for this solute (ßCD, gammaCD, and ß/gammaCD).
Revista:
JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0022-3549
Año:
2014
Vol.:
103
N°:
1
Págs.:
197 - 206
Gels obtained by complexation of octablock star polyethylene oxide/polypropylene oxide copolymers ( Tetronic 90 R4) with alpha-cyclodextrin (alpha- CD) were evaluated as matrices for drug release. Both molecules are biocompatible so they can be potentially applied to drug delivery systems. Two different types of matrices of Tetronic 90 R4 and alpha-CD were evaluated: gels and tablets. These gels are capable to gelifying in situ and show sustained erosion kinetics in aqueous media. Tablets were prepared by freeze-drying and comprising the gels. Using these two different matrices, the release of two model molecules, L-tryptophan ( Trp), and a protein, bovine serum albumin ( BSA), was evaluated. The release profiles of these molecules from gels and tablets prove that they are suitable for sustained delivery. Mathematical models were applied to the release curves from tablets to elucidate the drug delivery mechanism. Good correlations were found for the fittings of the release curves to different equations. The results point that the release of Trp from different tablets is always governed by Fickian diffusion, whereas the release of BSA is governed by a combination of diffusion and tablet erosion.
Revista:
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
ISSN:
1860-5397
Año:
2014
Vol.:
10
Págs.:
3127 - 3135
All mammals lose their ability to produce lactase (ß-galactosidase), the enzyme that cleaves lactose into galactose and glucose, after weaning. The prevalence of lactase deficiency (LD) spans from 2 to 15% among northern Europeans, to nearly 100% among Asians. Following lactose consumption, people with LD often experience gastrointestinal symptoms such as abdominal pain, bowel distension, cramps and flatulence, or even systemic problems such as headache, loss of concentration and muscle pain. These symptoms vary depending on the amount of lactose ingested, type of food and degree of intolerance. Although those affected can avoid the uptake of dairy products, in doing so, they lose a readily available source of calcium and protein. In this work, gels obtained by complexation of Tetronic 90R4 with ¿-cyclodextrin loaded with ß-galactosidase are proposed as a way to administer the enzyme immediately before or with the lactose-containing meal. Both molecules are biocompatible, can form gels in situ, and show sustained erosion kinetics in aqueous media. The complex was characterized by FTIR that evidenced an inclusion complex between the polyethylene oxide block and ¿-cyclodextrin. The release profiles of ß-galactosidase from two different matrices (gels and tablets) of the in situ hydrogels have been obtained. The influence of the percentage of Tetronic in media of different pH was evaluated. No differences were observed regarding the release rate from the gel matrices at pH 6 (t50 = 105 min). However, in the case of the tablets, the kinetics were faster and they released a greater amount of 90R4 (25%, t50 = 40¿50 min). Also, the amount of enzyme released was higher for mixtures with 25% Tetronic. Using suitable mathematical models, the corresponding kinetic parameters have been calculated. In all cases, the release data fit quite well to the Peppas¿Sahlin model equation, indicating that the release of ß-galactosidase is governed by a combination of diffusion and erosion processes. It has been observed that the diffusion mechanism prevails over erosion during the first 50 minutes, followed by continued release of the enzyme due to the disintegration of the matrix.
Revista:
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN:
1388-3127
Año:
2013
Vol.:
75
N°:
3-4
Págs.:
241 - 246
Tyrosol (TY), 4-(2-hydroxyethyl)phenol, is an olive oil biophenol with antioxidant activity and positive effects on human health. This study has investigated the interactions of TY with cyclodextrins (CD) and a CD polymer. Complexation of TY with beta-CD, hydroxypropyl-beta-CD (HP-beta-CD), and methyl-beta-CD (Me-beta-CD) has been evaluated both in aqueous solution and in the solid state. The techniques employed in solution to determine the apparent stability constants of the respective complexes were fluorescence and UV-visible spectroscopies. Complexation with beta-CD and its derivatives involved an increase of both the UV absorbance and the intrinsic fluorescence of TY; a bathochromic shift of the UV spectrum was detected as well. The apparent stability constants obtained with native beta-CD, Me-beta-CD and HP-beta-CD presented similar values. Complexes in the solid state were obtained by coevaporation and kneading. They were characterised by X-ray diffraction analysis and differential thermal analysis. The interaction of TY with beta-CD led to a crystalline complex; the same diffraction pattern was obtained by coevaporation and kneading. The complexes obtained with methyl- and HP-beta-CD were amorphous irrespective of the preparation method. In addition, the retention of TY in an insoluble polymer of CD crosslinked with epichlorohydrin has been quantified. In approximately 20 min, 1 mg of TY per gram of polymer was retained.
Revista:
EUROPEAN POLYMER JOURNAL
ISSN:
0014-3057
Año:
2013
Vol.:
49
N°:
12
Págs.:
3912 - 3920
Hydrogel networks of ¿, ß or ¿-cyclodextrin (CD) and mixtures of ¿/ß or ß/¿ CDs have been obtained using epichlorohydrin (EP) as a crosslinking agent. Discs of the resulting polymers were evaluated as drug carriers for controlled release using the antiinflammatory naproxen (NAP) as a model drug. ßCD polymer (ßCDP) has shown the highest amount of drug loaded and the lowest one corresponds to the polymer containing ¿CD, in agreement with the affinities of NAP for the corresponding cyclodextrins.
In addition, in vitro drug release kinetics assays from the loaded discs have been carried out. The different release profiles at simulated physiological conditions of pH and temperature have been correctly defined, identifying in each case the release mechanisms. Using suitable mathematical models, the apparent diffusional coefficients and the corresponding kinetic parameters have been calculated. It can be inferred that a simple Fickian diffusion mechanism occurs, except for the mixed polymers at pH 1.2 (anomalous transport) and in the case ¿CDP at pH 7.0 (burst phenomenon). Furthermore, the diffusion and relaxation contributions have been determined for the mixed polymers in order to achieve progress in the design of new polymer matrices according to the structure of the selected drugs.
Revista:
CARBOHYDRATE POLYMERS
ISSN:
0144-8617
Año:
2012
Vol.:
87
N°:
3
Págs.:
2024 - 2030
beta-cyclodextrins (beta CD) are cyclic oligosaccharides which have been widely employed for pharmaceutical applications. Discs of insoluble polymers were synthesized by crosslinking beta-cyclodextrins with the reagent epichlorohydrin. In this work, the possibility of employing a polymer containing 60 +/- 3% beta CD for drug delivery of two antiinflammatory (naproxen and nabumetone) and two antifungal drugs (naftifine and terbinafine) has been investigated. The interaction of Naproxen with the polymers was evidenced by X-ray diffractometry, FTIR spectroscopy and differential thermal analysis. Drug release kinetics were carried out at physiological conditions of pH and temperature, and kinetic and diffusion constants were calculated by fitting 60% of the release profile according to the Korsmeyer-Peppas equation. Also, diffusion coefficients were calculated according to the simplified Higuchi model. The drug release followed a simple Fickian diffusion mechanism for all the model drugs. This study suggests that these hydrogel matrices are potentially suitable as sustained release systems.
Revista:
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN:
1388-3127
Año:
2011
Vol.:
70
N°:
3 - 4
Págs.:
415 - 419
Complexation of ebastine (EB) with hydroxypropyl and methyl-beta-cyclodextrin (HP-beta-CD and Me-beta-CD) was studied in aqueous solutions and in the solid state. The formation of inclusion complexes in aqueous solutions was analysed by the solubility method. The assays were designed using low CD concentrations compared with the solubility of these derivatives in order to avoid non-inclusion phenomena and to obtain a linear increase in EB solubility as a function of CD concentration. The values of complexation efficiency for HP-beta-CD and Me-beta-CD were 1.9 x 10(-2) and 2.1 x 10(-2), respectively. It seems that the non polar character of the methyl moiety slightly favoured complexation. In relation to solid state complexation, 1: 1 EB: CD systems were prepared by kneading, and by heating a drug-CD mixture at 90 degrees C. They were analysed using X ray diffraction analysis by comparison with their respective physical mixtures. A complex with a characteristic diffraction pattern similar to that of the channel structure of beta-CD was formed with Me-beta-CD in 1: 1 melted and 1: 2 EB: CD kneaded systems. Complexation with HP-beta-CD was not clearly evidenced because only a slight reduction of drug crystallinity was detected. Finally, the loading of EB in two beta-CD polymers cross-linked with epichlorohydrin yielded 7.3 and 7.7 mg of EB/g polymer respectively.
Revista:
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN:
1388-3127
Año:
2011
Vol.:
69
N°:
3 - 4
Págs.:
469 - 474
beta-cyclodextrin insoluble polymers (beta CDP), a type of hydrogels with a high swelling capacity, can be obtained by crosslinking beta-cyclodextrin (beta CD) with epichlorohydrin. Terbinafine (TB) is an oral and topical antifungal drug that can be housed into the cavity of beta-cyclodextrin, so it seems probable that the drug could interact with the insoluble beta CDP. Different organic molecules can be sorbed on the polymer network and also included within the beta CD cavities, so these hydrogels have potential applications in the pharmaceutical field as drug carriers. In this work, the sorption of TB on beta CDP and the optimal conditions to load the polymer with the drug were studied. Sorption kinetics and Freundlich isotherms of TB on beta CDP at 25A degrees C were obtained and the influence of several parameters on the sorption process of TB was investigated. It was found that a high initial concentration of drug, high TB:beta-CD molar ratios and low ionic strengths were the most favourable conditions. No significant influence of temperature was observed. Moreover, the sorption kinetic profile obtained for terbinafine was compared to that of naftifine, another antifungal agent of similar structure. Terbinafine presented higher affinity for the polymer, according to the higher stability constant of the drug-beta CD inclusion complex. In relation to the release studies from the loaded polymer, 0.1 M HCl was the most favourable medium to allow the release of the drug.
Revista:
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN:
1388-3127
Año:
2011
Vol.:
69
N°:
3-4
Págs.:
411 - 415
The mechanisms of sorption and release of solutes from polymeric materials synthesised by cross-linking ß-cyclodextrin (ß-CD) with epichlorohydrin have been investigated. Gemfibrozil (pKa 4.7) was chosen as model solute. The polymers were obtained by suspension (P1) and block polymerisation (P2). Both P1 and P2 had similar ß-CD contents (65 and 64%) and their swelling capacities were 5.0 and 5.8 cm3/g, respectively. The sorption of gemfibrozil kinetic data in water and in aqueous solutions at pH 2.8 and 7.0 were fitted to a hyperbolic equation and they were studied by applying the Weber and Morris and the Elovich equations. P2 presented faster rates and higher sorption capacities in water and at pH 2.8. The mechanisms of sorption were pH-dependent. In water, the sorption rate was determined by the diffusion of gemfibrozil in the polymer network and fitted the Weber and Morris equation. At pH 2.8 a better adjustment to the Elovich equation suggested a significant influence of the inclusion in the ß-CD cavities. The release kinetics at pH 7.0 was controlled by drug solubilisation and presented maximum release values of 90 (P1) and 95% (P2), with a suitable regeneration of the loaded polymer. In water, the release was slower, fitted a hyperbole and the mechanism was controlled by drug solubility and also by the polymeric geometry. Finally, release assays were carried out from discs of loaded polymer in a medium that simulated the gastrointestinal tract.
Revista:
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN:
1388-3127
Año:
2010
Vol.:
66
N°:
3 - 4
Págs.:
393 - 402
Terbinafine (TB) is an allylamine derivative used as oral and topical antifungal agent. The physicochemical properties of the complexes between TB and different cyclodextrins (CDs): alpha-CD, beta-CD, hydroxypropyl beta-CD, methyl beta-CD and gamma-CD, have been studied in pH 12 aqueous solutions at 25 A degrees C and in the solid state. Different phase solubility profiles of TB in the presence of CDs have been obtained: A(L) type for TB with hydroxypropyl beta-CD and gamma-CD, A(P) type for the complexes with methyl beta-CD and alpha-CD, while a B(S) profile was found for TB-beta-CD. The apparent stability constants of the complexes were calculated at 25 A degrees C from the phase solubility diagrams. The higher increase of TB solubility, up to 200-fold, together with the higher value of the stability constant were found for the complex with methyl beta-CD. Solid systems of 1:1 drug:CD molar ratio were prepared and characterised using X-ray diffraction patterns, thermal analysis and FTIR spectroscopy. The coevaporation method can be considered the best method in preparing these solid complexes. The complexes of TB with natural CDs, except with alpha-CD, were crystalline, whereas the methyl and hydroxypropyl derivatives gave rise to amorphous phases. Dissolution rate studies have been performed with TB-beta-CD and TB-HP beta-CD complexes, showing a positive influence of complexation on the drug dissolution.
Nacionales y Regionales
Título:
Optimización del desarrollo y gestión de envases con materiales nanoparticulados sostenibles para uso alimentario
Código de expediente:
0011-1383-2019-000005 PI017
Investigador principal:
María Icíar Vélaz Rivas
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2019 GN Centros
Fecha de inicio:
01/12/2018
Fecha fin:
30/11/2019
Importe concedido:
61.120,00€
Otros fondos:
-
Título:
Transportadores de ADN/ARN de nueva generación:cápsides moleculares basadas en carbohidratos
Código de expediente:
PID2021-124247OB-C22
Investigador principal:
María de la Concepción Tros de Ilarduya Apaolaza
Financiador:
AGENCIA ESTATAL DE INVESTIGACION
Convocatoria:
2021 AEI Proyectos de Generación del Conocimiento
Fecha de inicio:
01/09/2022
Fecha fin:
31/08/2025
Importe concedido:
84.700,00€
Otros fondos:
Fondos FEDER
Título:
Funcionalización de envases con nuevos materiales nanoparticulados para uso alimentario
Código de expediente:
0011-1383-2018-000005 PI039 ENMATNAN
Investigador principal:
María Icíar Vélaz Rivas
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2018 GN Centros
Fecha de inicio:
01/02/2018
Fecha fin:
30/11/2018
Importe concedido:
46.223,74€
Otros fondos:
-
Título:
Incorporación de fármacos en fibras poliméricas para liberación dérmica: aplicación al tratamiento de leishmaniasis cutánea e infecciones de la piel
Código de expediente:
PID2020-112713RB-C21
Investigador principal:
Paul Alain Nguewa Kamsu, Gustavo González Gaitano
Financiador:
AGENCIA ESTATAL DE INVESTIGACION
Convocatoria:
2020 AEI PROYECTOS I+D+i (incluye Generación del conocimiento y Retos investigación)
Fecha de inicio:
01/01/2021
Fecha fin:
31/12/2024
Importe concedido:
84.700,00€
Otros fondos:
-
Título:
Diseño, desarrollo y evaluación de nuevos sistemas dendriméricos y glicodendriméricos de aplicación a terapia génica antitumoral
Código de expediente:
CTQ2015-64425-C2-2-R
Financiador:
MINISTERIO DE CIENCIA E INNOVACIÓN
Convocatoria:
2015 MINECO RETOS INVESTIGACION. PROYECTOS I+D+i
Fecha de inicio:
01/01/2016
Fecha fin:
31/12/2019
Importe concedido:
60.500,00€
Otros fondos:
Fondos FEDER
Título:
Materiales nanocompuestos termoplásticos con propiedades antimicrobianas con potenciales aplicaciones en la industria agroalimentaria
Código de expediente:
MAT2014-59116-C2-2-R
Investigador principal:
Gustavo González Gaitano
Financiador:
MINISTERIO DE CIENCIA E INNOVACIÓN
Convocatoria:
2014-MINECO Retos Investigación
Fecha de inicio:
01/01/2015
Fecha fin:
31/12/2018
Importe concedido:
72.600,00€
Otros fondos:
Fondos FEDER
