Thiolated alginate-based multiple layer mucoadhesive films of metformin forintra-pocket local delivery: in vitro characterization and clinical assessment

Abstract

Introduction: Periodontal disease broadly defines group of conditions in which the supportive structure of the tooth (periodontium) is destroyed. Recent studies suggested that the anti-diabetic drug metformin hydrochloride (MF) has an osteogenic effect and is beneficial for the management of periodontitis.

Objective: Development of strong mucoadhesive multiple layer film loading small dose of MF for intra-pocket application.

Methodology: Multiple layer film was developed by double casting followed by compression method. Either 6% carboxy methyl cellulose sodium (CMC) or sodium alginate (ALG) constituted the inner drug (0.6%) loaded layer. Thiolated sodium alginate (TSA; 2 or 4%) constituted the outer drug free layers to enhance mucoadhesion and achieve controlled drug release. Optimized formulation was assessed clinically on 20 subjects.

Results: Films were uniform, thin and hard enough for easy insertion into periodontal pockets. Based on water uptake and in vitro drug release, CMC based film with 4% TSA as an outer layer was the optimized formulation with enhanced mucoadhesion and controlled drug release (83.73% over 12?h). SEM showed the effective fabrication of the triple layer film in which connective lines between the layers could be observed. FTIR examination suggests possibility of hydrogen bonding between the –NH groups of metformin and –OH groups of CMC. DSC revealed the presence of MF mainly in the amorphous form. Clinical results indicated improvement of all clinical parameters six months post treatment.

Conclusion: The results suggested that local application of the mucoadhesive multiple layer films loaded with metformin hydrochloride was able to manage moderate chronic periodontitis.     

Performance analysis of an air rock thermocline TES tank for concentrated solar power plants using the coupled DEM–CFD approach

Clean Technologies and Environmental Policy - One of the most common solutions currently available to meet future energy needs in the world is concentrated solar power (CSP) plants combined with...     

Influence of carbon nanotubes and dispersions of SiC on the physical and mechanical properties of pure copper and copper‐nickel alloy

This paper investigates the physical and mechanical properties of copper‐nickel alloy (at 50 wt.%–50 wt.%) and pure copper, mixed with various types of reinforcement materials such as carbon nanotubes (0.5 wt.%–2 wt.%) as nanoparticles, silicon carbide (1 wt.%–4 wt.%) as microparticles. The acquired composite specimens characteristics were estimated such as microstructure, density, electrical and thermal conductivity, hardness, and compression stress properties to determine the suitable reinforcement percentage that has the best physical and mechanical properties with different main matrix material whether copper‐nickel mechanical alloying or pure copper powder. The micron‐sized silicon carbide and nanosized carbon nanotubes were added to improve the mechanical and physical properties of the composite. The electrical and thermal conductivity of pure copper alloy enhanced compared with the copper‐nickel alloy matrix material. The hardness and compression yield stress of both pure copper and copper‐nickel composites have enhancement values and for copper‐nickel base composites hardness and compression yield stress have enhanced with the most positive enhancement values to examined an optimum percentage of reinforcing material.     

Compact Patch Antenna Array for 60 GHz Millimeter-Wave Broadband Applications

Wireless Personal Communications - In this study, a wide-band compact patch antenna array is developed for 60 GHz band applications. The antenna array consists of eight identical elements....     

In vivo behavior of bioactive phosphate glass-ceramics from the system P2O5–Na2O–CaO containing TiO2

Soda lime phosphate bioglass-ceramics with incorporation of small additions of TiO₂ were prepared in the metaphosphate and pyrophosphate region, using an appropriate two-step heat treatment of controlled crystallization defined by differential thermal analysis results. Identification and quantification of crystalline phases precipitated from the soda lime phosphate glasses were performed using X-ray diffraction analysis. Calcium pyrophosphate (β-Ca₂P₂O₇), sodium metaphosphate (NaPO₃), calcium metaphosphate (β-Ca(PO₃)₂), sodium pyrophosphate (Na₄P₂O₇), sodium calcium phosphate (Na₄Ca(PO₃)₆) and sodium titanium phosphate (Na₅Ti(PO₄)₃) phases were detected in the prepared glass-ceramics. The degradation of the prepared glass-ceramics were carried out for different periods of time in simulated body fluid at 37 °C using granules in the range of (0.300–0.600 mm). The released ions were estimated by atomic absorption spectroscopy and the surface textures were measured by scanning electron microscopy. Evaluation of in vivo bioactivity of the prepared glass-ceramics was carried through implanting the samples in the rabbit femurs. The results showed that the addition of 0.5 TiO₂ mol% enhanced the bioactivity while further increase of the TiO₂ content decreased the bioactivity. The effect of titanium dioxide on the bioactivity was interpreted on the basis of its action on the crystallization process of the glass-ceramics.     

Noise distribution of Mueller matrices retrieved with active rotating polarimeters

Two methods used to retrieve Mueller matrices from intensity measurements are revisited. It is shown that with symmetry or orthogonality considerations, numerical inversions of polarimetric equations can be avoided. With the obtained analytical formulas, noise propagation can be analyzed. If the intensity noise is a Gaussian white noise, the noise of Mueller matrices features remarkable properties. Mueller components are mutually correlated according to a scheme that involves decomposition into four blocks of 2x2 matrices. Variances are unequally distributed: the middle 2x2 block has the highest variance, the element on the bottom right has the lowest. These characteristics have been validated on experimental Mueller images of the free space.     

Development and validation of a rapid HPLC method for the determination of ketotifen in pharmaceuticals

In the present study, a simple, sensitive, rapid, and stability-indicating high performance liquid chromatographic (HPLC) method with ultraviolet detection for the analysis of ketotifen was developed and validated. The method was applied to the determination of ketotifen in pharmaceutical formulations (tablets and syrups). The HPLC method utilized isocratic elution technique with a reversed phase C8 column, detection at 297 nm and a mixture of methanol, triethylamine phosphate buffer (pH 2.8; 0.04 M), and tetrahydrofuran (43: 55: 2, v/v/v) as mobile phase at a flow rate of 1.2 mL/min. Total analysis time was about 7 min with typical retention time of ketotifen of about 5 min. The method was validated for selectivity, linearity, accuracy, and precision following International Conference of Harmonization, 1996 (ICH) recommendations. Due to its simplicity and accuracy, the method can be used for routine quality control analysis.     

Performance analysis of air cycle refrigerator integrated desiccant system for cooling and dehumidifying warehouse

In this paper, the performance of air cycle refrigerator integrated desiccant system used to cool and dehumidify warehouse is analyzed theoretically. Simulation analysis is carried out to calculate the system coefficient of performance, cooling effects and the humidity change under different values of pressure ratio, storage zone temperature inside dock and outdoor air conditions. Also, the effect of the air cycle and the rotor parameters on the system performance is evaluated. From the simulation result it is found that, the desiccant system has the ability to supply air to the dock area at very low humidity. The system coefficient of performance increases due to the exhaust heat recovery on the desiccant system, and this enhancement can be more than 100%. The coefficient of performance of the proposed system is greater than that of a conventional system under the same operating conditions.     

Upgrading of coker distillate under variable hydrotreating operating conditions

Studies on hydrotreating coker distillates, produced from a delayed coker unit were done using a commercially available CoMo/γ-Al₂O₃ catalyst, on which 0.2 wt% P₂O₅ was added in order to improve its characteristics. The experimental studies were conducted in a fixed-bed continuous-reactor (cata-test unit) at temperatures (300–400 °C) and total hydrogen pressure (40–65 bar). These conditions have affected the feedstock characteristics and great reduction of sulfur, aromatics and boiling ranges. Other improvements were obtained in diesel index (DI) due to hydrogenation reaction of aromatics and desulfurization of its sulfur contents.     

Upgrading the adhesion properties of a fast‐curing epoxy using hydrophilic/hydrophobic hyperbranched poly(amidoamine)s

A homologous series of hyperbranched polymers (HBPs) was prepared following a well‐defined method and their formation in a polymeric form bearing different extents of branching with amine functional groups at the terminals was verified using different techniques such as Fourier Transform Infrared, ¹H Nuclear Magnetic Resonance, Differential Scanning Calorimetry, and Gel Permeation Chromatography. Toughening of a commercially available fast cure epoxy was aimed through reactive blending with the formed HBPs that exhibit variation in polarity and branching according to the relevant synthesis strategy employed for each polymer. The mechanical properties (impact resistance, pull‐off adhesion, and bending) of the resulting coating films pertaining to each epoxy formulation after adhering to metal substrates revealed obvious progress in their performance with respect to a control sample that was hardened exclusively in absence of any HBP. The results were explained on the light of the ability of this class of materials to impose flexibility and dilute the intensive crosslink density associated frequently with the rapid curing of epoxy systems. The extent of gained enhancement for each formulation was accounted for by the molecular architecture of the HBPs, their degrees of branching, polarity, and relative reactive contents of primary amino groups in each case. In addition, the influence of these parameters on a proper wetting over the substrate and morphology of the films in each case was also studied using scanning electron microscopy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013