scholarly journals Silane Modification of Mesoporous Materials for the Optimization of Antiviral Drug Adsorption and Release Capabilities in Vaginal Media

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1416
Author(s):  
Elena Whittle ◽  
Araceli Martín-Illana ◽  
Raul Cazorla-Luna ◽  
Fernando Notario-Perez ◽  
María Dolores Veiga-Ochoa ◽  
...  
Keyword(s):  
Mesoporous Materials ◽  
Release Kinetics ◽  
Antiviral Drug ◽  
Interaction Mechanism ◽  
Coupling Reaction ◽  
Weibull Model ◽  
Drug Adsorption ◽  
Physicochemical Interactions ◽  
Functionalized Materials ◽  
Silane Modification

Three different functionalities have been incorporated into mesoporous materials by means of a coupling reaction with the siloxanes 3-glycidoxypropyl-trimethoxysilane (GLYMO), 3-methacryloxypropyl-trimethoxysilane (MEMO), and 3-mercaptopropyl-trimethoxysilane (MPTMS). The disposition of the different functional groups, as well as the interaction mechanism, with the mesoporous substrate has been identified. The amount of the antiviral drug acyclovir (ACV) adsorbed depends not only on the available surface area but also on the chemical or physicochemical interactions between functionalities. The drug adsorption isotherm of the materials functionalized with GLYMO and MPTMS follow mechanisms dependent on the different surface coverage and the possibilities to establish physicochemical interactions between the drug molecule and the functionalities. On the contrary, when functionalizing with MEMO, the dominant adsorption mechanism is characteristic of chemically bonded adsorbates. The ACV release kinetics is best fitted to the Weibull model in all the functionalized materials. When the MTPMS is used as a functionalizing agent, the drug diffusion occurs at low kinetics and homogeneously along the mesoporous channels.

STUDIES ON UREA CO-INCLUSION COMPLEXES OF EBASTINE FOR STEEP IMPROVEMENT IN DISSOLUTION PROFILE

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (08) ◽  
pp. 35-45
Author(s):  
M. Dhall ◽  
◽  
A. K. Madan
Keyword(s):  
Dissolution Rate ◽  
Release Kinetics ◽  
Thermal Studies ◽  
Physical Stability ◽  
Molar Fraction ◽  
Aqueous Solubility ◽  
Weibull Model ◽  
Complexing Agent ◽  
Content Uniformity ◽  
Dissolution Profile

Urea co-inclusion technique has been successfully utilized for steep enhancement in dissolution rate of ebastine (EB), a BCS class II potent drug. EB is a novel second generation H1 receptor antagonist used for prevention of chronic idiopathic urticaria and allergic rhinitis. It exhibits low aqueous solubility and consequent poor bioavailability. In the present study, EB was engulfed in urea channel/tunnels along with rapidly complexing agent (RCA). Resulting complexes of EB (EBUCIC) were characterized by DSC, FTIR, XRD and 1H-NMR. Minimum proportion of RCA for incorporation of EB in hexagonal urea was determined calorimetrically. The thermal studies indicated increase in heat of decomposition with increasing molar fraction of RCA in EBUCICs, ensuring better physical stability of complexes. Content uniformity study depicted uniform composition formulation of EB. Weibull model described release kinetics of EB. Enhancement in dissolution rate ensures urea co-inclusion to be a useful approach for development of rapid/instantaneous release dosage forms.

scholarly journals A novel selective fluorescent chemosensor for Fe3+ ions based on phthalonitrile dimer: synthesis, analysis, and theoretical studies

2020 ◽  
Vol 44 (5) ◽  
pp. 1254-1264
Author(s):  
Shaya AL-RAQA ◽  
İpek ÖMEROĞLU ◽  
Doğan ERBAHAR ◽  
Mahmut DURMUŞ
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Interaction Mechanism ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Density Functional Theory Calculations ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Cross Coupling Reaction ◽  
Ft Ir

Phenyl-4,4-di(3,6-dibutoxyphthalonitrile) (3) was synthesized by the reaction of 1,4-phenylenebisboronic acid (1) and 4-bromo-3,6-dibutoxyphthalonitrile (2), using Suzuki cross-coupling reaction. The newly synthesized compound (3) was characterized by FT-IR, MALDI-MS, ESI-MS, 1H-NMR, 13C-NMR, and 13C-DEPT-135-NMR. The fluorescence property of phenyl-4,4-di(3,6- dibutoxyphthalonitrile) (3) towards various metal ions was investigated by fluorescence spectroscopy, and it was observed thatthe compound (3) displayed a significantly ‘turn-off’ response to Fe3+, which was referred to 1:2 complex formation between ligand (3) and Fe3+. The compound was also studied via density functional theory calculations revealing the interaction mechanism of the molecule with Fe3+ ions.

scholarly journals Application of Supercritical Solvent Impregnation for Production of Zeolite Modified Starch-Chitosan Polymers with Antibacterial Properties

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4717 ◽  
Author(s):  
Jelena Pajnik ◽  
Ivana Lukić ◽  
Jelena Dikić ◽  
Jelena Asanin ◽  
Milan Gordic ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Antibacterial Properties ◽  
Water Vapor Permeability ◽  
Weibull Model ◽  
Vapor Permeability ◽  
E Coli ◽  
Supercritical Solvent ◽  
Composite Polymers ◽  
Before And After ◽  
Impregnation Time

In the present study, supercritical solvent impregnation (SSI) has been applied to incorporate thymol into bio-composite polymers as a potential active packaging material. Thymol, a natural component with a proven antimicrobial activity, was successfully impregnated into starch-chitosan (SC) and starch-chitosan-zeolite (SCZ) films using supercritical carbon dioxide (scCO2) as a solvent. Experiments were performed at 35 °C, pressures of 15.5 and 30 MPa, and an impregnation time in the range of 4–24 h. The highest impregnation yields of SC films with starch to chitosan mass ratios of 1:1 and 1:2 were 10.80% and 6.48%, respectively. The addition of natural zeolite (15–60%) significantly increased the loading capacity of films enabling thymol incorporation in a quantity of 16.7–27.3%. FTIR and SEM analyses were applied for the characterization of the films. Mechanical properties and water vapor permeability of films before and after the impregnation were tested as well. Thymol release kinetics in deionized water was followed and modeled by the Korsmeyer-Peppas and Weibull model. SCZ films with thymol loading of approximately 24% exhibited strong antibacterial activity against E. coli and methicillin-resistant Staphylococcus (S.) aureus (MRSA).

scholarly journals Eudragit FS 30D as a potential polymer for use in the technology of preparing matrix tablets contain metronidazole – an experimental and mathematical modeling study

2015 ◽  
Vol 28 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Tomasz Letmanski ◽  
Anna Kodym ◽  
Piotr Weber ◽  
Michal Lewandowski ◽  
Andrzej Wisniewski ◽  
...  
Keyword(s):  
Active Substance ◽  
Sodium Lauryl Sulfate ◽  
Release Kinetics ◽  
Weibull Model ◽  
Matrix Tablets ◽  
Polysorbate 80 ◽  
Lauryl Sulfate ◽  
Modified Release ◽  
Eudragit Rs ◽  
Time Period

Abstract The aim of this study was to examine the usefulness of a pH-dependent copolymer - Eudragit FS - for employment in the technology of preparing modified release metronidazole matrix tablets. In addition, in our work, Eudragit RL and Eudragit RS were included in the composition of some formulations, as well as sodium lauryl sulfate and polysorbate 80. As part of the study of the dissolution test, the similarity coefficient (f2) for the obtained profiles was calculated, and mathematic models were used to estimate the kinetics and mechanism of active substance release. In our work, it was observed that the inclusion of polymer Eudragit FS alone in the tablet composition ensured a modified release of the active substance for 10 h. After this time period, the amount of metronidazole determined in the acceptor fluid was 71% - 81% of the declared dose. Modification of the composition by the addition of surfactants resulted in an increased release of the active substance of up to 98%. This effect was dependent on the type of surfactant and its quantitative ratio to the Eudragit FS. Similar release profiles were obtained for tablets containing Eudragit RS and sodium lauryl sulfate, as well as Eudragit RS and polysorbate 80. Depending on the composition of tablets, metronidazole release proceeded in accordance with either first or second-order kinetics. We calculated as well, that the differing masses of Eudragit FS in the studied formulations correlates with the order of release kinetics (p < 0.002). Such an effect was validated using the Weibull model, wherein, in all the studied formulations, the release rate was seen as a decreasing function of time. An analysis of data according to the Ritger-Peppas model and the Peppas-Sahlin model for some formulations, indicated that the mechanism of active substance release from matrix tablets is diffusion.

Computational study on favipiravir adsorption onto undoped- and silicon-decorated C60 fullerenes

2017 ◽  
Vol 16 (02) ◽  
pp. 1750011 ◽  
Author(s):  
Cemal Parlak ◽  
Özgür Alver ◽  
Mustafa Şenyel
Keyword(s):  
Drug Delivery ◽  
Gas Phase ◽  
Density Functional ◽  
Computational Study ◽  
Antiviral Drug ◽  
Interaction Mechanism ◽  
C60 Fullerene ◽  
Water Media ◽  
Silicon Doped ◽  
C60 Fullerenes

Adsorption and interaction mechanisms of fullerene-based complex systems for possible drug delivery vehicles have been at the center of increasing attention. In the scope of this work, the interaction mechanism between an important antiviral drug favipiravir and silicon-doped/undoped C60 fullerenes have been investigated using density functional theory (DFT). Calculations were carried out in both gas phase and water media to see the possible solvent effects. The effect of adsorption of the favipiravir on the SiC59 fullerene system and the nature of interaction were examined by analyzing the band shifts in the carbonyl stretching vibrations and natural bond orbital (NBO) properties of the examined complexes. Some important structural and electronic properties were reported and discussed as well. It was observed that doping the C60 fullerene nanocages with silicon atom enhanced the adsorption mechanism and calculations performed in water media gave rise to more stable complexes for silicon-doped systems compared to the results obtained for the gas phase. Results and parameters found in the present search reveal further insights into the drug delivery systems.

scholarly journals Amino Functionalized Micro-Mesoporous Hybrid Particles for the Sustained Release of the Antiretroviral Drug Tenofovir

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3494
Author(s):  
Araceli Martin-Illana ◽  
Raul Cazorla-Luna ◽  
Fernando Notario-Pérez ◽  
Roberto Ruiz-Caro ◽  
Luis Miguel Bedoya ◽  
...  
Keyword(s):  
Sustained Release ◽  
Release Kinetics ◽  
Sexual Transmission ◽  
Antiviral Agents ◽  
Interaction Mechanism ◽  
Hybrid Particles ◽  
Silane Molecule ◽  
Weibull Models ◽  
Sexual Transmission Of Hiv ◽  
Mesoporous Particles

The sustained release of an antiretroviral agent to women mucosa has been proved as an excellent strategy to reduce the sexual transmission of HIV. Hybrid micro-mesoporous particles have been synthesized and functionalized with a silane coupling agent followed by loading the antiretroviral tenofovir. It has been observed that the disposition of the silane molecule on the surface of the particles determines the interaction mechanism with the antiretroviral molecule loaded independently on the surface area of the particles. In this sense, available and free amino groups are required to achieve a smart pH-responsive material, a condition that is only achieved in those materials containing a silane chemisorbed monolayer. Moreover, the modulation of the release kinetics attributed to the presence of the silane monolayer covering the mesopores has been confirmed by fitting the releasing curves to the first order and Weibull models. The developed micro-mesoporous particles have been demonstrated to be excellent smart-release vehicles for antiviral agents and can be safely used in polymer mucoadhesive vaginal gels.

scholarly journals Study of Immobilization by Esteric Bond of 2-(m-Nitrophenyl)-4-(β- Carboxymethyl)-Δ2-Oxazolinone-5 on Gellan

2016 ◽  
Vol 5 (2) ◽  
pp. 121
Author(s):  
Popa Marcel ◽  
Sunel Valeriu ◽  
Balaita Rusu Lacramioara ◽  
Basu Cristina
Keyword(s):  
Controlled Release ◽  
Ir Spectroscopy ◽  
Release Kinetics ◽  
Coupling Reaction ◽  
Zero Order ◽  
Experimental Program ◽  
Active Principle ◽  
Covalent Bonds ◽  
Zero Order Kinetics ◽  
Basic Hydrolysis

The paper studies the coupling reaction, through ester-type covalent bonds, of an oxazolone derived from the N-(m-nitrobenzoyl)-L-asparagic acid, on gellan (a polysaccharide of microbian synthesis), in conditions of activation with dicyclohexyl carbodiimide. Based on a centered, rotatory, composed, second order experimental program, the regression equation describing the dependence of the amount of active principle, chemically bounded to the support, on the reaction’s parameters (support/active principle ratio, active principle/activator ratio, duration) is obtained. One may observe that the efficiency of the coupling reaction is maximum when employing the parameters’ highest values, over the variation domain established. The coupling product has been characterized through elemental analysis and IR spectroscopy. For the establishment of the capacity of the active principle’s controlled release by the polymer-active principle system thus obtained, drug’s release kinetics from the polysaccharidic support is studied in conditions of basic hydrolysis. The oxazolone release from the coupling products, by basic hydrolysis proceeds conformely to a zero order kinetics, proving their retard activity.

scholarly journals Influence of Hydrophilic Polymers on theβFactor in Weibull Equation Applied to the Release Kinetics of a Biologically Active Complex ofAesculus hippocastanum

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Justyna Kobryń ◽  
Sandra Sowa ◽  
Monika Gasztych ◽  
Andrzej Dryś ◽  
Witold Musiał
Keyword(s):  
Release Kinetics ◽  
Weibull Model ◽  
Biologically Active ◽  
Fickian Diffusion ◽  
Horse Chestnut ◽  
Clinical Activity ◽  
Weibull Function ◽  
Biological Origin ◽  
Triterpenoid Saponins ◽  
Weibull Equation

Triterpenoid saponins complex of biological origin, escin, exhibits significant clinical activity in chronic venous insufficiency, skin inflammation, epidermal abrasions, allergic dermatitis, and acute impact injuries, especially in topical application. The aim of the study is the comparison of various hydrogel formulations, as carriers for a horse chestnut seed extract (EH). Methylcellulose (MC), two polyacrylic acid derivatives (PA1 and PA2), and polyacrylate crosspolymer 11 (PC-11) were employed. The release rates of EH were examined and a comparison with the Weibull model equation was performed. Application of MC as the carrier in the hydrogel preparation resulted in fast release rate of EH, whereas in the case of the hydrogel composed with PC-11 the release was rather prolonged. Applied Weibull function adhered best to the experimental data. Due to the evaluated shape parameterβ, in the Weibull equation, the systems under study released the active compound according to the Fickian diffusion.

scholarly journals Modulation of the Release of a Non-Interacting Low Solubility Drug from Chitosan Pellets Using Different Pellet Size, Composition and Numerical Optimization

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 175 ◽  
Author(s):  
Partheniadis ◽  
Gkogkou ◽  
Kantiranis ◽  
Nikolakakis
Keyword(s):  
Numerical Optimization ◽  
Extended Release ◽  
Release Kinetics ◽  
Size Composition ◽  
Weibull Model ◽  
Liquid Volume ◽  
Pellet Size ◽  
Drug Levels ◽  
Drug Content ◽  
Normal Diffusion

Two size classes of piroxicam (PXC) pellets (mini (380–550 μm) and conventional (700–1200 μm)) were prepared using extrusion/spheronization and medium viscosity chitosan (CHS). Mixture experimental design and numerical optimization were applied to distinguish formulations producing high sphericity pellets with fast or extended release. High CHS content required greater wetting liquid volume for pellet formation and the diameter decreased linearly with volume. Sphericity increased with CHS for low-to-medium drug content. Application of PXRD showed that the drug was a mixture of form II and I. Crystallinity decreased due to processing and was significant at 5% drug content. Raman spectroscopy showed no interactions. At pH 1.2, the dissolved CHS increased ‘apparent’ drug solubility up to 0.24 mg/mL while, at pH 5.6, the suspended CHS increased ‘apparent’ solubility to 0.16 mg/mL. Release at pH 1.2 was fast for formulations with intermediate CHS and drug levels. At pH 5.6, conventional pellets showed incomplete release while mini pellets with a CHS/drug ratio ≥2 and up to 21.25% drug, showed an extended release that was completed within 8 h. Numerical optimization provided optimal formulations for fast release at pH 1.2 with drug levels up to 40% as well as for extended release formulations with drug levels of 5% and 10%. The Weibull model described the release kinetics indicating complex or combined release (parameter ‘b’ > 0.75) for release at pH 1.2, and normal diffusion for the mini pellets at pH 5.6 (‘b’ from 0.63 to 0.73). The above results were attributed mainly to the different pellet sizes and the extensive dissolution/erosion of the gel matrix was observed at pH 1.2 but not at pH 5.6.

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