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Oral bioavailability and hypoglycaemic activity of tolbutamide/cyclodextrin inclusion complexes

Veiga, F.; Fernandes, C.; Teixeira, F.
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
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The purpose of the present study was to evaluate the enhancement of tolbutamide (TBM) oral bioavailability and hypoglycaemic activity through complexation with [beta]-cyclodextrin ([beta]-CD) and hydroxypropyl-[beta]-cyclodextrin (HP-[beta]-CD). TBM and its freeze-dried inclusion complexes were administered to rabbits (New zealand breed; n=6), in a dose of 20 mg/kg. TMB plasma levels were measured by HPLC and glucose levels were analysed according to Trinder (Trinder, P., 1969. Determination of glucose in blood using glucose oxidase with an alternative oxygen acceptor. Ann. Clin. Biochem. 6, 24-28). The pure drug attained a maximum of plasma concentration (Cmax) of 18.58±3.27 [mu]g/ml at 8.5 h (Tmax), whereas with inclusion complexes, Cmax increased about two times and appeared at ca. 4 h. AUC0-24 of complexes was about 1.6 times as much as that of the pure drug. Thus, the extent of oral absorption of TBM from inclusion complexes was significantly greater and faster when compared with drug alone. In addition, without cyclodextrins the maximum hypoglycaemic effect (CVGmax) of TBM (34.1%) was observed at 5.6 h (Tgmax). CVGmax of TBM/[beta]-CD and TBM/HP-[beta]-CD inclusion complexes were 34.1% (at 6.5 h) and 37.7% (at 5.1 h), respectively. AAC0-24 of inclusion complexes was 1.4 times larger than that of pure drug. Hence...

Strategies to improve the solubility and stability of stilbene antioxidants: a comparative study between cyclodextrins and bile acids

Silva, Filomena; Figueiras, Ana; Gallardo, Eugenia; Nerín, Cristina; Domingues, Fernanda C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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Aiming at the development of an active food packaging, the goal of this study was to increase stilbenes (resveratrol (RV), pterostilbene (PT) and pinosylvin (PS)) aqueous solubility and stability using hydropropyl-cyclodextrins (HP-CDs) and bile salts. To evaluate stilbene concentration, an HPLC-DAD method was validated. Stilbene solubility was improved by the formation of inclusion complexes and micellar systems with higher solubility values obtained for the inclusion complexes with cyclodextrins. Inclusion complexes revealed a 1:1 stoichiometry for RV and PT and a 1:2 for PS. Solid state characterisation was carried out using X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry. 1H NMR studies were also performed to characterise the prepared complexes. Photostability studies revealed that CDs were able to increase stilbene photostability at 4 °C. This work showed that stable stilbene solutions can be achieved using hydroxypropyl-CDs, contributing for their incorporation in several materials for the food and pharmaceutical industries.

Binary and ternary inclusion complexes of finasteride in HP beta CD and polymers: Preparation and characterization

ASBAHR, Ana Carolina C.; FRANCO, Luzia; BARISON, Andersson; SILVA, Caroline W. P.; FERRAZ, Humberto G.; RODRIGUES, Leticia N. C.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
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The aim of this study was to determine whether inclusion complexes between 2-hydroxypropyl-beta-cyclodextrin (HP beta CD) and finasteride (FIN) are formed, and to characterize these. Equimolar FIN/HP beta CD solid systems in the presence or absence of 0.1% (w/v) of polyvinylpyrrolidone K30 (PVP K30) or 0.3% of chitosan were prepared by coevaporation and freeze-drying methods. The systems were characterized by phase solubility, NMR, DSC, and XRD analysis. The results suggest that true binary and ternary inclusion complexes were formed. (c) 2009 Elsevier Ltd. All rights reserved.

Obtention and Evaluation of Inclusion Complexes of Furosemide with beta-ciclodextrin and hidroxipropil-beta-ciclodextrin: Effects on Drug`s Dissolution Properties

SPRICIGO, Rodrigo; BOTELHO, Katia C. A.; CONSIGLIERI, Vladi O.; SERRA, Cristina. H. R.
Fonte: COLEGIO FARMACEUTICOS PROVINCIA DE BUENOS AIRES Publicador: COLEGIO FARMACEUTICOS PROVINCIA DE BUENOS AIRES
Tipo: Artigo de Revista Científica
POR
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Obtention and Evaluation of Inclusion Complexes of Furosemide with beta-ciclodextrin and hidroxipropil-beta-ciclodextrin: Effects on Drug`s Dissolution Properties. The purpose of this study was to prepare, characterize and evaluate the dissolution behavior of inclusion complexes of furosemide with beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD). Solid complexes of furosemide with P-CD and-HP-beta-CD were prepared by using a freeze-drying method. Physical mixtures were prepared for comparison. The inclusion complexes were characterized by differential scanning calorimetry (DSC), Infrared (IR) and dissolution test. ""In vitro"" dissolutions assays were performed at pH 1,2; pH 4,5 and pH 6,8 media for a 60 min period. Statistical analysis employing ANOVA and Tukey`s Test, for the dissolution efficiency values (ED%), showed that complexation of furosemide with both cyclodextrins improved significantly ED% of the drug in all tested media, suggesting a minor pH influence on dissolution properties of the drug.

Binary and ternary inclusion complexes of dapsone in cyclodextrins and polymers: preparation, characterization and evaluation

Grebogi, Ivanna H.; Tibola, Ana Paula O. V.; Barison, Andersson; Grandizoli, Caroline W. P. S.; Ferraz, Humberto Gomes; Rodrigues, Leticia N. C.
Fonte: SPRINGER; DORDRECHT Publicador: SPRINGER; DORDRECHT
Tipo: Artigo de Revista Científica
ENG
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Dapsone (DAP) is a synthetic sulfone drug with bacteriostatic activity, mainly against Mycobacterium leprae. In this study we have investigated the interactions of DAP with cyclodextrins, 2-hydroxypropyl-beta-cyclodextrin (HP beta CD) and beta-cyclodextrin (beta CD), in the presence and absence of water-soluble polymers, in order to improve its solubility and bioavailability. Solid systems DAP/HP beta CD and DAP/beta CD, in the presence or absence of polyvinylpyrrolidone (PVP K30) or hydroxypropyl methylcellulose (HPMC), were prepared. The binary and ternary systems were evaluated and characterized by SEM, DSC, XRD and NMR analysis as well as phase solubility assays, in order to investigate the interactions between DAP and the excipients in aqueous solution. This study revealed that inclusion complexes of DAP and cyclodextrins (HP beta CD and beta CD) can be produced in order to improve DAP solubility and bioavailability in the presence or absence of polymers (PVP K30 and HPMC). The more stable inclusion complex was obtained with HP beta CD, and consequently HP beta CD was more efficient in improving DAP solubility than beta CD, and the addition of polymers had no influence on DAP solubility or on the stability of the DAP/CDs complexes.

Citotoxicidade da desidrocrotonina livre e veiculada em sistemas de liberação controlada : nanoesferas de acido poli-lactico-co-glicolico (PLGA) e complexos de inclusão com ciclodextrinas; Cytotoxicity of free dehydrocrotonin and dehydrocrotonin-loaded controlled delivery systems, poly-lactide-co-glycode acid (PLGA) nanospheres and inclusion complexes with cyclodextrins

Daniel Henrique do Amaral
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/11/2005 PT
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A droga desidrocrotonina (DHC), isolada da planta Croton cajucara, é conhecida pelas suas atividades biológicas, entretanto apresenta uma vasta e conhecida toxicidade. Neste trabalho foram preparadas formulações contendo DHC associada a polímeros (PLGA) ou ciclodextrinas (beta, metil-beta e hidroxipropil-beta) para obter nanopartículas poliméricas e complexos de inclusão, respectivamente. Objetivamos neste trabalho a preparação das formulações de veiculação de DHC, sua caracterização e avaliação de parâmetros de toxicidade in vitro visando o estudo comparativo dos efeitos da DHC livre e veiculada. Células V79 e hepatócitos de ratos, sistemas celulares bem estabelecidos, permitiram avaliar alvos celulares como lisossomos, mitocôndrias e ácidos nucléicos frente aos possíveis danos tóxicos causados pela DHC. Nos hepatócitos, além dos parâmetros citados acima, também foi avaliada a quantidade de GSH existente nessas células, bem como a quantificação da peroxidação lipídica através da formação de TBARS e a atividade enzimática de enzimas do sistema de metabolização de drogas após tratamento com DHC livre e veiculada nos sistemas de liberação controlada ? nanoesferas de PLGA e complexos de inclusão com ciclodextrinas. Nossos estudos em forma geral...

A-βcyclodextrin/siloxane hybrid polymer: synthesis, characterization and inclusion complexes

Abbehausen,Camilla; Formiga,André L. B.; Sabadini,Edvaldo; Yoshida,Inez V. P.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
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A hybrid polymer derived from siloxane and β-cyclodextrin (β-CD) was obtained by reaction of β-CD with g-isocyanatopropyltriethoxysilane (IPTS), followed by hydrolysis/condensation reactions, generating a β-CD-modified polysilsesquioxane resin (PSS-β-CD). PSS-β-CD hybrid was characterized by infrared spectroscopy and 13C and 29Si nuclear magnetic resonance. This hybrid was typically amorphous and thermally stable up to 180 ºC. PSS-β-CD was able to form films and its morphology was evaluated by scanning electron microscopy. The capability of β-CD grafted in the hybrid polymer to form inclusion complex was evaluated by the formation of a β-CD-phenolphthalein complex using UV-Vis spectroscopy. Even without changes in pH, the red form of phenolphthalein converts to the colorless one when PSS-β-CD is immersed in the solution. Theoretical calculations (AM1 and DFT methods) show that the complex is formed through the inclusion of the phenolate ring into β-CD cavity, favoring the colorless form of phenolphthalein by more than 15 kcal mol-1.

Formulation and evaluation of mucoadhesive buccal patch of acyclovir utilizing inclusion phenomenon

Saxena,Ankita; Tewari,Gulab; Saraf,Shubhini Awasthi
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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Mucoadhesive buccal patch releasing drug in the oral cavity at a predetermined rate may present distinct advantages over traditional dosage forms, such as tablets, gels and solutions. A buccal patch for systemic administration of acyclovir in the oral cavity was developed using polymers hydroxy propyl methyl cellulose (K4M), hydroxy propyl methyl cellulose (K15M), sodium carboxy methyl cellulose and poly vinyl pyrolidone (K30), plasticizer poly ethylene glycol (400) and a backing membrane of Eudragit (RL100). The films were evaluated in terms of swelling, residence time, mucoadhesion, release, and organoleptic properties. The optimized films showed lower release as compared to controlled drug delivery systems. Hence, an inclusion complex of acyclovir was prepared with hydrophilic polymer hydroxylpropyl beta-cyclodextrin in the molar ratio of 1:1. The inclusion complex was characterized by optical microscopy, FAB mass spectroscopy, and FTIR spectroscopy. Patches formulated with the acyclovir inclusion complex were evaluated along the same lines as those containing acyclovir alone. The in vitro release data revealed a substantial increase from 64.35% to 88.15% in the case of PS I and PS II batches, respectively, confirming the successful use of inclusion complexes for the formulation of buccal patch of acyclovir.

Computational Modeling of Inclusion Complexes of β-Cyclodextrin with enantiomers of Salsolinol, N-Methyl-Salsolinol, and 1-Benzyl-Tetrahydroisoquinoline

Huang, Ming-Ju; Quan, Zhe; Liu, Yi-Ming
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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Capillary electrophoresis with β-CD as a chiral selector has successfully separated the two enantiomers of salsolinol, N-methyl-salsolinol, and 1-benzyl-tetrahydroisoquinoline. The migration times of each enantiomer in capillary electrophoresis reflect the stability of their β-CD inclusion complexes. This paper reports a computational modeling study of the inclusion complexes of β-cyclodextrin (β-CD) with salsolinol, N-methyl-salsolinol, and 1-benzyl-tetrahydroisoquinoline by using PM3 (Parametric Method 3) semi-empirical molecular orbital calculations and the ONIOM hybrid method. Two types of the inclusion complexes, cis- and trans-orientations, are considered for each enantiomer of the guest molecules, salsolinol, N-methyl-salsolinol, and 1-benzyl-tetrahydroisoquinoline. In the cis-orientation, the nitrogen in the salsolinol, N-methyl-salsolinol, and 1-benzyl-tetrahydroisoquinoline points toward the secondary hydroxyls of the β-CD, while in the trans-orientation, the nitrogen in salsolinol, N-methyl-salsolinol, and 1-benzyl-tetrahydroisoquinoline points toward the primary hydroxyls of the β-CD. We found that the stabilization energies of these inclusion complexes from these PM3 and ONIOM different methods correlate very well with the migration order deduced from the study of capillary electrophoretic separation.

Preparation and Solid-State Characterization of Inclusion Complexes Formed Between Miconazole and Methyl-β-Cyclodextrin

Ribeiro, Andreza; Figueiras, Ana; Santos, Delfim; Veiga, Francisco
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Publicado em 31/10/2008 EN
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The aim of this study is to confirm the formation of inclusion complexes between miconazole (MCZ) and two derivatives of beta-cyclodextrin, methyl-beta-cyclodextrin (MβCD) and 2-hydroxypropyl-beta-cyclodextrin (HPβCD) in aqueous solution by phase solubility studies. Inclusion complexes with MβCD in the solid state were then prepared by different methods, i.e., kneading, coevaporation (COE), spray-drying (SD), and lyophilization (LPh). The physicochemical properties of these complexes were subsequently studied by means of differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction techniques. Phase solubility diagrams with MβCD and HPβCD were classified as AP type, indicating the formation of 1:1 and 1:2 stoichiometric inclusion complexes. The apparent stability constants (KS) calculated from the phase solubility diagram were 145.69 M−1 (K1:1) and 11.11 M−1 (K1:2) for MβCD and 126.94 M−1 (K1:1) and 2.20 M−1 (K1:2) for HPβCD. The method of preparation of the inclusion complexes in the solid state was shown to greatly affect the properties of the formed complex. Hence, the LPh, SD, and COE methods produce true inclusion complexes between MCZ and MβCD. In contrast...

Enhancement of Oral Bioavailability of Cilostazol by Forming its Inclusion Complexes

Patel, Samir G.; Rajput, Sadhana J.
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Publicado em 21/05/2009 EN
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The study was designed to investigate the effect of cyclodextrins (CDs) on the solubility, dissolution rate, and bioavailability of cilostazol by forming inclusion complexes. Natural CDs like β-CD, γ-CD, and the hydrophilic β-CD derivatives, DM-β-CD and HP-β-CD, were used to prepare inclusion complexes with cilostazol. Phase solubility study was carried out and the stability constants were calculated assuming a 1:1 stoichiometry. Solid cilostazol complexes were prepared by coprecipitation and kneading methods and compared with physical mixtures of cilostazol and cyclodextrins. Prepared inclusion complexes were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) studies. In vitro dissolution study was performed using phosphate buffer pH 6.4, distilled water, and HCl buffer pH 1.2 as dissolution medium. The optimized inclusion complex was studied for its bioavailability in rabbit and the results were compared with those of pure cilostazol and Pletoz-50. Phase solubility study showed dramatic improvement in the solubility of drug by formation of complexes, which was further increased by pH adjustment. The dissolution rate of cilostazol was markedly augmented by the complexation with DM-β-CD. DSC and XRD curves showed sharp endothermic peaks indicating the reduction in the microcrystallinity of cilostazol. Selected inclusion complex was also stable at ambient temperature up to 6 months. The in vivo study revealed that DM-β-CD increased the bioavailability of cilostazol with low variability in the absorption. Among all cilostazol–cyclodextrins complexes...

Physicochemical Characterization, in vitro Release and Permeation Studies of Respirable Rifampicin-Cyclodextrin Inclusion Complexes

Patil, J. S.; Suresh, Sarasija
Fonte: Medknow Publications Publicador: Medknow Publications
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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The inclusion complexes of rifampicin with sucralose and β-cyclodextrins were prepared by spray drying method. The complexes were characterized by size analyses, scanning electron microscopy, differential scanning calorimetry and x-ray diffraction methods. The results indicated the amorphous nature of resultant products. The solubility, in vitro release and skin permeation of the drug were enhanced after formation of inclusion complexes. The in vitro release and permeation of the inclusion complexes were greater in simulated lung fluid as compared to pure drug.

Dissolution behavior of β-cyclodextrin molecular inclusion complexes of aceclofenac

Dua, Kamal; Pabreja, Kavita; Ramana, M. V.; Lather, Vinny
Fonte: Medknow Publications Pvt Ltd Publicador: Medknow Publications Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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The objective of the present investigation was to study the effect of β-cyclodextrin (β-CD) on the in vitro dissolution of aceclofenac (AF) from molecular inclusion complexes. Aceclofenac molecular inclusion complexes in 1:1 and 1:2 M ratio were prepared using a kneading method. The in vitro dissolution of pure drug, physical mixtures, and cyclodextrin inclusion complexes was carried out. Molecular inclusion complexes of AF with β-CD showed a considerable increase in the dissolution rate in comparison with the physical mixture and pure drug in 0.1 N HCl, pH 1.2, and phosphate buffer, pH 7.4. Inclusion complexes with a 1:2 M ratio showed the maximum dissolution rate in comparison to other ratios. Fourier transform infrared spectroscopy and differential scanning calorimetry studies indicated no interaction between AF and β-CD in complexes in solid state. Molecular modeling results indicated the relative energetic stability of the β-CD dimer-AF complex as compared to β-CD monomer-AF. Dissolution enhancement was attributed to the formation of water soluble inclusion complexes with β-CD. The in vitro release from all the formulations was best described by first-order kinetics (R2 = 0.9826 and 0.9938 in 0.1 N HCl and phosphate buffer...

Preparation and Characterization of Pioglitazone Cyclodextrin Inclusion Complexes

Pandit, V; Gorantla, R; Devi, K; Pai, RS; Sarasija, S
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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481.994%
Pioglitazone, a class II Biopharmaceutical Classification System drug having poor water solubility and slow dissolution rate may have a negative impact on its subtherapeutic plasma drug levels leading to therapeutic failure. In order to improve its water solubility and thus dissolution, cyclodextrin complexation technique was followed. The phase solubility studies were carried using three different types of cyclodextrins viz., β, methyl-β and γ-cyclodextrins. The Gibbs free energy was calculated in order to determine ease of the complexation. Binary systems of pioglitazone with cyclodextrins were prepared by kneading method and spray drying method. The phase solubility profiles with all the three cyclodextrins were classified as AL-type, indicating the formation of 1:1 stoichiometric inclusion complexes. The complexation capability of cyclodextrins with pioglitazone increased in the order of methyl-β > β > γ-cyclodextrin. The Gibbs free energy was found to be in the order γ > methyl-β > β cyclodextrin. Characterization of inclusion complexes was done by solubility studies, in vitro dissolution studies, Fourier transformation-infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and X-ray powder diffractometry studies. Inclusion complexes exhibited higher rates of dissolution than the corresponding physical mixtures and pure drug. Greater solubility was observed with spray-dried methyl-β cyclodextrin complexes (2.29 ± 0.001 mg/ml) in comparison to the kneaded methyl-β cyclodextrin complexes (1.584 ± 0.053 mg/ml) and pure drug (0.0714 ± 0.0018 mg/ml).

Electrospinning and characterization of self-assembled inclusion complexies

Liu, Yang
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
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L’électrofilage est une technique permettant de fabriquer des fibres polymériques dont le diamètre varie entre quelques nanomètres et quelques microns. Ces fibres ont donc un rapport surface/volume très élevé. Les fibres électrofilées pourraient trouver des applications dans le relargage de médicaments et le génie tissulaire, comme membranes et capteurs chimiques, ou dans les nanocomposites et dispositifs électroniques. L’électrofilage était initialement utilisé pour préparer des toiles de fibres désordonnées, mais il est maintenant possible d’aligner les fibres par l’usage de collecteurs spéciaux. Cependant, il est important de contrôler non seulement l’alignement macroscopique des fibres mais aussi leur orientation au niveau moléculaire puisque l’orientation influence les propriétés mécaniques, optiques et électriques des polymères. Les complexes moléculaires apparaissent comme une cible de choix pour produire des nanofibres fortement orientées. Dans les complexes d’inclusion d’urée, les chaînes polymères sont empilées dans des canaux unidimensionnels construits à partir d’un réseau tridimensionnel de molécules d’urée liées par des ponts hydrogène. Ainsi, les chaînes polymère sonts très allongées à l’échelle moléculaire. Des nanofibres du complexe PEO-urée ont été préparées pour la première fois par électrofilage de suspensions et de solutions. Tel qu’attendu...

Herstellung und Charakterisierung eines b-Cyclodextrin / Kamillen-CO2-Extrakt-Komplexes als Wirkkomponente einer halbfesten Arzneiform; Preparation and characterisation of a camomile ointment containing a supercritical carbon dioxide camomile extract/b-cyclodextrin inclusion complex

Waleczek, Katharina Joanna
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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Das Ziel dieser Arbeit ist die Entwicklung einer Kamillensalbe, welche eine feste Einschlussverbindung aus den Bestandteilen eines Kamillen-CO2-Extraktes in beta-Cyclodextrin enthält, um die Stabilität des Extraktes zu verbessern und den intensiven Kamillengeruch der Salbe zu reduzieren. Um die molekulare Zusammensetzung eines b-Cyclodextrin-Komplexes mit reinen Kamillenbestandteilen oder als Bestandteil des ätherischen Kamillenöls zu untersuchen, werden Phasen-Löslichkeits-Diagramme erstellt. Es resultiert ein Bs-Typ mit einer Stabilitätskonstante von 273 M-1 für reines (-)-a-Bisabolol und 304 M-1 für (-)-a-Bisabolol als Bestandteil des ätherischen Öls. Die Komplexe werden nach der Knetmethode hergestellte, wobei Konsistenz und Aussehen entsprechend dem Verhältnis von CO2-Extrakt zu b-Cyclodextrin variieren. Komplexe aus einem Teil CO2-Extrakt und 2 bis 5 Teilen b-Cyclodextrin führen zu pastösen Produkten, wohingegen aus 7 bis 10 Teilen b-Cyclodextrin und einem Teil CO2-Extrakt stabile Komplexe in Form von frei fließenden Pulvern resultieren. Die Wiederfindungsrate von b-Farnesen und (-)-a-Bisabolol in den Komplexen beträgt 90 - 99 Cis- und trans-En-In-Dicycloether (EID, syn. Spiroether) sind weniger stabil; unabhängig von der Komplexzusammensetzung werden 3 - 40 der Gastmoleküle beim Waschen mit n-Hexan entfernt. Der Stabilitätstest der Komplexe und der daraus hergestellten Salbe über 3 Monate zeigt...

Potentiometric characterisation of cyclodextrin inclusion complexes of local anaesthetics

Brandariz Lendoiro, Isabel; Iglesias Martínez, Emilia
Fonte: Taylor and Francis Ltd. Publicador: Taylor and Francis Ltd.
Tipo: Artigo de Revista Científica
ENG
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The complexation of several local anaesthetics by β and γ-cyclodextrins was studied by potentiometry with glass electrode. Tetracaine and dibucaine complexation constants were determined at 25°C in the presence of 0.1 M of NaCl. It was found that prilocaine and lidocaine complexes cannot be detected.

Encapsulação, caracterização físico-química e estudo teórico do fármaco tiabendazol em 'beta'-ciclodextrina; Encapsulation, physico chemical characterization and theoretical study of drug thiabendazole in 'beta'-cyclodextrin

Guilherme Lionello Alexandrino
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 21/07/2011 PT
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Tiabendazol (TBZ) é um fármaco pouco solúvel em água (66 mg/mL), derivado do benzimidazol, com ampla aplicação farmacológica, devido a suas propriedades anti-helmíntica, fungicida e bactericida. O aumento em sua solubilidade pode ser atingido preparando complexos de inclusão com Ciclodextrinas (bCD), que são polissacarídeos cíclicos de D-(+)-glicopiranose unidas por meio de ligações glicosídicas a-1,4, cuja estrutura resulta em um ambiente interno hidrofóbico e uma superfície e extremidades hidrofílicas. Neste trabalho, a preparação de complexos de inclusão entre TBZ e bCD foi realizada pelo método de co-precipitação, em duas metodologias que diferiram na etapa de solubilização do TBZ: empregando etanol ou meio ácido com HCl em pH 2.2. Os complexos preparados foram caracterizados no estado sólido, através das técnicas de espectroscopia de absorção no i.v., difratometria de raios-X e análise termogravimétrica. Em solução, a estabilidade termodinâmica do complexo de inclusão TBZ:bCD foi investigada em meios que simulam os fluídos gástrico e intestinal humano, sem enzimas, determinando as constantes de equilíbrio K nas temperaturas 25 (150 ± 31), 37 (85 ± 32) e 45 ºC (83 ± 23), e as funções termodinâmicas de formação DHº (-24 kJ/mol)...

Free 2-propen-1-amine derivative and inclusion complexes with beta-cyclodextrin: scanning electron microscopy, dissolution, cytotoxicity and antimycobacterial activity

Souza,Ana O. de; Santos-Jr,Rubens R.; Sato,Daisy N.; Azevedo,Marcelo M. M. de; Ferreira,Denise A.; Melo,Patrícia S.; Haun,Marcela; Silva,Célio L.; Durán,Nelson
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2004 EN
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Inclusion complexes and physical mixtures of isomeric mixture of E/Z (50:50) of 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-3-(4-bromophenyl)-N,N-dimethyl-2-propen-1-amine (BBAP) and beta-cyclodextrin (beta-CD) in the molar proportion of 1:1 and 1:2 were analyzed by scanning electron microscopy. The dissolution behavior of BBAP and of the inclusion complexes were also evaluated for six hours. By scanning electron microscopy (SEM), it was possible to observe an inclusion complex formed between BBAP and beta-CD by co-evaporation, either in the molar proportion of 1:1 or 1:2. In the physical mixtures, no complex was observed as previously detected by physicochemical analysis. The dissolution studies showed that the inclusion complexes BBAP/beta-CD 1:1 and 1:2 released respectively 49.07 ± 1.48 and 40.26 ± 3.90% of BBAP during six hours. Free BBAP was less soluble than the inclusion complex and reached 9.00 ± 0.75% of dissolution. Biological assays, such as cytotoxicity to J774 macrophages and to a permanent lung fibroblast cell line (V79), indicated that the BBAP does not exhibit any additional toxic effect with the beta-CD complexes. However, the complexes were less cytotoxic to V79 cells than the free form. The BBAP/beta-CD inclusion complexes were more effective (MIC) than the free compound on several mycobacteria strains. Similar behavior was observed for BBAP/beta-CD complexes and rifampicin...

Formulation and evaluation of mucoadhesive buccal patch of acyclovir utilizing inclusion phenomenon

Saxena, Ankita; Tewari, Gulab; Saraf, Shubhini Awasthi
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/12/2011 ENG
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Mucoadesivos bucais liberadores de fármacos para a cavidade oral com taxa de liberação pré-determinada podem apresentar distintas vantagens em relação às formas farmacêuticas convencionais como comprimidos, géis e soluções. Neste trabalho, um adesivo bucal para administração sistêmica de aciclovir através da cavidade oral foi desenvolvido empregando-se os polímeros hidroxipropilmetil celulose (K4M), hidroxipropilmetil celulose (K15M), carboximetil celulose sódica e polivinil pirrolidona (K30), polietilenoglicol plastificado (400) e uma membrana suporte de Eudragit (RL100). Os filmes obtidos foram avaliados em termos de intumescimento, tempo de residência, mucoadesão, liberação e propriedades organolépticas. Os filmes otimizados apresentaram liberação mais lenta em comparação a outros sistemas de liberação controlada. Desta maneira, um complexo de inclusão de aciclovir foi preparado com o polímero hidrofílico hidroxipropil beta-ciclodextrina em proporções molares 1:1. O complexo de inclusão foi caracterizado por microscopia ótica, espectrometria de massas FAB e espectroscopia FTIR. Os adesivos formulados com o complexo de inclusão de aciclovir foram avaliados em paralelo com adesivos contendo aciclovir isolado. Os dados de liberação in vitro revelaram um aumento substancial...