Hydrophilic Matrix Research Articles

SAXS and SANS Studies on the Phase‐Separated Network Structure of Amphiphilic Copolymer Composed of Poly(dimethyl siloxane) and Poly(N,N‐dimethyl acrylamide) Gels Swollen in Water and a Water/Methanol Mixture

The phase‐separated network structure of amphiphilic copolymer gels composed of poly(dimethyl siloxane) (PDMS) and poly(N,N‐dimethyl acrylamide) (PDMAA) in water and a water/methanol mixture is investigated by small angle X‐ray (SAXS) and small angle neutron scatterings (SANS). The copolymerized gel of PDMS‐co‐PDMAA exhibits bicontinuous phase‐separated domains (hydrophilic and hydrophobic) with a periodicity at the nanometer scale, and the PDMS hydrophobic domain forms a cylinder‐like core. The hydrophilic region is confirmed to be selectively swollen by water and methanol. Deuterated water and deuterated methanol are used for the SAXS and SANS measurements. The electron density and scattering length density (SLD) of the hydrophilic region vary according to the mixture ratio and adsorption amount of the solvents. The SAXS profiles (curve and scattering intensity) significantly change with the ratio D2O/methanol‐d4. On the other hand, the SANS profiles do not change significantly. The deuterated solvents cannot be distributed into the PDMS domain (core). The solvents and PDMAA hydrophilic form matrix. In these situations, as for SANS, the SLD difference between the PDMS and matrix remains almost constant. As for SAXS, in contrast to SANS, the electron density difference between the PDMS and hydrophilic domain varies with the ratio of water to methanol. The SAXS and SANS profiles can be simulated using a core‐shell cylindrical model. We found that an interfacial thin region exists between the hydrophobic PDMS and hydrophilic PDMAA/solvents. This interfacial region is determined to be composed of a solvent–poor PDMAA.

Formulation and In-vitro evaluation of sustained release matrix tablet of Metformin hydrochloride

The low bioavailability and short half-life of Metformin hydrochloride (MH) make the development of sustained-release forms desirable. Present work involves preparation and optimization of sustained release matrix tablet of MH by direct compression method using HPMC K 100 and ethyl cellulose as a matrix forming polymer. Avicel was added as a direct compaction vehicle to improve the compaction behavior of Metformin which otherwise exhibits poor compaction behavior which again is further increased by its relatively high dose. Hydrophilic matrix of HPMC alone resulted in initial burst of Metformin release, however when combined with ethyl cellulose drug release was slowed down and thereafter it became optimal at particular concentration of polymers.
 Keywords: Metformin, HPMC, Ethyl cellulose, sustained release, matrix, tablet.

Formulation of sustained release bioadhesive minitablets containing solid dispersion of levofloxacin for once daily ocular use

This study aimed to increase ocular residence time of levofloxacin by formulation into zero-order sustained release mucoadhesive minitablets for once daily administration using a hydrophobic–hydrophilic polymeric matrix. Levofloxacin was first formulated into solid dispersion with different ratios of Eudragit® RS then the resulting solid dispersion was mixed with different concentrations of Carbopol® and other excipients to be finally compressed into minitablets. A 24 full factorial design was employed to estimate the effects and interactions of two formulation factors, and to establish their relationships with selected responses in the developed minitablets. The studied factors were: drug to Eudragit® RS ratio, and percent of Carbopol® in the minitablets. Sixteen ocular minitablets formulations were prepared and evaluated for the cumulative percentages drug release at 6, 12, and 24 h, as well as mucoadhesion time, mucoadhesive strength, and swelling index as response variables. After optimizing the responses, the optimized formulation was found to be stable on sterilization using gamma-irradiation and storage at 40 °C/75% RH for six months. In vivo testing of the optimized formulation showed that the minitablets extended levofloxacin release up to 24 h without causing any ocular irritation. The optimized formulation exhibited superior microbiological activity compared to the commercial product.

Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring.

In a simple and instant procedure for detecting fish freshness, a hydrogel and hydrophilic pectin matrix membrane was used successfully as an optical pH sensor by immobilizing the chromoionophore ETH 5294 (CI), which is very selective and sensitive for the membrane. The Pe/CI optical pH sensor exhibited excellent linearity between pH 5 and pH 9, with a sensor response time of 5 min and reproducibility of 1.49% relative standard deviation (RSD). The sensor showed response stability for 15 days and a response reduction of 8.6%. The sensor’s capability was demonstrated by the detection of fish freshness for 17 days at 4 °C.

Development of a novel method utilising dissolution imaging for the measurement of swelling behaviour in hydrophilic matrices

A variety of imaging techniques are currently used within the field of pharmaceutics to help understand and determine a wide range of phenomena associated with drug release from hydrophilic matrix tablets. This work for the first time aims at developing an appropriate testing imaging methodology using a surface dissolution imaging instrument (SDI2) for determining the swelling of whole compacts using hypromellose as a model hydrophilic matrix former. The influence of particle morphology (CR and DC grades) and two compressional forces (5 and 15 kN) on the initial swelling behaviour of hypromellose were investigated. The results showed that a lower absorbance of 50 mAu with a wider measurement zone proved successful in determining the edge of the gel layer and growth measurements in real-time with high level of details under flow. Despite the differences in the morphology of the grades of hypromellose tested, it was however discovered that gel growth was statistically similar between them which may be attributed to their similar chemistry. This novel method also highlighted differences in the hydrated polymer’s appearance which may have been as a result of differences in porosity and solid fraction. This information is of great importance to a formulator as gel growth plays a crucial role in determining drug release from polymer compacts.

The behavior of compatibility of Ap-g-PHMA to impact polypropylene/kenaf fibres composites

In this research, the behavior of poly(hexyl methacrylate (PHMA) grafted to Amylopectin (Ap-g-PHMA) as a compatibilizer on isotactic polypropylene (iPP)/kenaf fibres composites was studied. In order to improve interfacial interaction between hydrophilic kenaf fibre and hydrophobic matrix polypropylene (PP), Ap-g-PHMA is used as a compatibilizer. Field Emission Scanning Electron Microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), and mechanical testing were used for the composite characterization. The properties of binary and ternary systems have been analysed as a function of both fibre and compatibilizer content. All compatibilizer systems showed enhanced fibre dispersion and interfacial adhesion. It was found that using Ap-g-PHMA has a significant effect on composite properties. Fibre loading at 40% ratio showed very good effect regarding mechanical properties with 1% compatible agent. It is concluded, that incorporation of coupling agent had shown a better result than that of without it at a certain level of fibre loading.

High Anti-Interfering Profiling of Endogenous Glycopeptides for Human Plasma by the Dual-Hydrophilic Metal-Organic Framework.

Glycopeptidome profiling provides large-scale information about the glycosylation level of endogenous peptides, reflecting the dynamic processes of disease occurrences and developments. However, endogenous glycopeptides are usually submerged in complex fluids containing a wide variety of interference molecules, such as high concentration proteins, nonglycopeptides, and salts, which confounds attempts to identify glycopeptidome. Here, a dual-hydrophilic metal-organic framework is developed to selectively capture endogenous glycopeptides in complex biological fluid. The hydrophilic matrix material provides specific selectivity toward glycopeptides, while the deliberate surface regulation using hydrophilic species enhances its interaction with glycopeptides. This hydrophilic probe presents an extremely high performance in anti-interfering enrichment of glycopeptides from mimic complex samples, even when the molar ratio of immunoglobulin G versus bovine serum albumin was up to about 1:5000. More excitingly, in the practical application of glycopeptidome analysis, a total of 380 endogenous N-glycopeptides with 180 unique N-glycopeptide sites were identified from human plasma. This strategy is expected to broaden the application of dual-hydrophilic MOF-based materials, especially in dealing with the challenges of extremely complex biological samples.

Study on the Formulation and Pharmacotechnical Characterization of Hydrophilic Matrix Tables with Amiodarone Chlorhydrate

The study is based on new oral matrix tablets based on Kollidon®SR and chitosan, formulated in order to optimize the low oral bioavailability of amiodarone, a class III antiarrhythmic drug. Pharmacotechnical characterization included the analysis of flowability and compressibility properties (flow time, friction coefficient, angle of repose, Hausner ratio, Carr Index), and of pharmaco-chemical characteristics (mass and dose uniformity, thickness, diameter, mechanical strength, friability, degree of softening, in vitro release profile) of the tablets obtained using direct compression method. The results obtained have shown that both Kollidon®SR and chitosan may be used as matrix forming agents when combined with amiodarone. In vitro dissolution tests revealed that the nine formulations studied provided a prolonged release of amiodarone when compared to an industrial pharmaceutical product formulated as conventional release tablets.

A humidity‐sensing composite microfiber based on moisture‐induced swelling of an agarose polymer matrix

Herein, we present a humidity sensing microfiber based on an agarose polymer as a hydrophilic matrix and carbon nanotubes (CNT) as conducting fillers. The humidity‐dependent resistance is the key property of the composite microfiber as a humidity sensor. The composite microfiber composed of the agarose matrix swells or contracts depending on environmental humidity, leading to changes in junction density between the carbon nanotube conducting fillers inside the fiber. Moreover, adsorption of water molecules on the CNT filler could further increase the resistance of the microfiber sensor. The real‐time resistance monitoring of the microfiber shows reliable and reversible response to the repetitive changes in relative humidity with reasonable response rate. The tensile strength test confirms the mechanical robustness of the composite microfiber. The fabrication process is facile and presumably scalable. Such a practical fiber sensor could be readily used as a humidity‐sensing component in smart textile and wearable devices. POLYM. COMPOS., 40:3582–3587, 2019. © 2019 Society of Plastics Engineers

Cinnamate‐Functionalized Cellulose Nanocrystals as UV‐Shielding Nanofillers in Sunscreen and Transparent Polymer Films

AbstractSustainable and environmentally friendly UV‐shielding materials offer new opportunities in the formulation of the next generation cosmetic products. Cinnamate‐functionalized cellulose nanocrystals (Cin‐CNCs) prepared by esterifying CNCs with cinnamoyl chloride display strong UV absorption and high visible light transmittance. They are suitable for use as UV‐shielding nanofillers for sunscreen and transparent polymer films. The aqueous Cin‐CNC dispersion is waterborne, alcohol‐free, nonwhitening, waterproof, photo‐stable, and possesses a high sun protection factor (SPF). The SPF of Cin‐CNC aqueous dispersion is more than twice that of a popular commercial sunscreen at similar concentration. The Cin‐CNCs can serve as UV‐shielding and reinforcing nanofillers in hydrophilic and hydrophobic polymer matrices. The polyvinyl alcohol and polystyrene films incorporated with Cin‐CNCs display excellent UV‐shielding capacity and their Young's moduli are significantly enhanced.

Third-order nonlinearity and optical limiting properties of sol–gel-based bromophenol blue dye immobilized in silica–titania nanohybrid

Silica–titania (ST) nanohybrid and bromophenol blue (BPB) immobilized ST nanohybrid matrix are synthesized by low-temperature sol–gel route. The influence of BPB on the structural, morphological, and nonlinear optical properties of silica–titania nanohybrid was investigated by fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), atomic force microscopy (AFM), and z-scan technique. FTIR analysis confirms the chemical bonding between hydrophobic BPB dye species and hydrophilic type ST nanohybrid matrix. TEM and AFM analysis shows that the synthesized immobilized nanohybrid has inter-dispersed structure with average particle size of 0.8 ± 0.3 nm, smooth morphology, and low average surface roughness ~4.57 nm. The immobilization of BPB greatly improves the nonlinear refraction response and the nonlinear refractive index increases from 4.8 × 10–9 cm2/W to 451.9 × 10–9 cm2/W. Reverse saturable absorption is observed in both BPB and BPB/ST nanohybrid. However, the magnitude of nonlinear absorption coefficient in BPB/ST is lower than the BPB dye due to the occurrence of saturable absorption of the ST matrix. The optical limiting (OL) behavior of the BPB/ST nanohybrid reveals the low OL threshold at 0.33 kW/cm2. The synthesized BPB/ST nanohybrid has potential as an optical limiters for safety of photonic and optoelectronic devices under low-powered CW laser.

N-Acetylserotonin vs Melatonin: In-Vitro Controlled Release from Hydrophilic Matrix Tablets

Background: N-Acetylserotonin (NAS, N-acetyl-5-hydroxytryptamine) is the immediate precursor of the neurohormone melatonin (MT, N-acetyl-5-methoxytryptamine), which regulates sleep and wake cycles. NAS is produced by the N-acetylation of serotonin and is converted to melatonin via the action of Acetylserotonin O-methyltransferase (ASMT). Like melatonin, NAS acts as an agonist on the melatonin receptors MT1, MT2, and MT3. However, as NAS is abundant in specific brain areas, separate from serotonin and melatonin, it may also have discrete central effects. Indicatively, it has been reported that NAS may play a role in the antidepressant effects of Selective Serotonin Reuptake Inhibitors (SSRIs) and Monoamine Oxidase Inhibitors (MAOIs). </P><P> Objective: To decipher the controlled release characteristics of the active substances (NAS and MT) in a quick initial pace, aiming at a satisfactory sleep-onset related anti-depressive profile and prolonged release, thereafter, targeting at coping with poor sleep quality problems. </P><P> Methods: A series of hydrophilic matrix tablets involving as excipients, hydroxypropylmethylcellulose (HPMC) K15M, low viscosity sodium alginate, lactose monohydrate, and polyvinylpyrrolidone (PVP) M.W.: 10.000 and 55.000) was developed and tested at two dissolution media (pH 1.2 and 7.4). </P><P> Results: The results showed that commonly used excipients with different physicochemical properties govern the controlled release of NAS and MT from solid matrix systems. </P><P> Conclusions: We have demonstrated how broadly used excipients affect the in vitro controlled release of NAS and MT from solid pharmaceutical formulations. Currently, we extend our studies on the controlled release of these drugs using various other biopolymers/formulants of different physicochemical characteristics, which will help to highlight the discrete release profiles of NAS and MT.

A nanodiamond for structural biomimetic scaffolds

Bio-mechanically active scaffolds for tissue engineering combining hydrophilic polymeric matrix and nano-diamond fillers properties are presented and discussed in this paper. The resulting scaffolding materials revealed remarkable mechanical and biological properties to be exploited in advanced biomedical applications. The novel hybrid material is based on 2 and 5 volume % of detonation nano-diamond particles in a hydrophilic poly-(hydroxyl-ethylmethacrylate) matrix. According to its mechanical and biological properties, the nanocomposite shows a hybrid nature. The base analytical procedures for the preparation of the hybrid nanocomposites and some preliminary mechanical characteristics are presented. The proposed hybrid system has been considered for potential biomimetic, osteoconductive and osteoinductive scaffolds application in bio-mechanically active bone scaffolds for osteoblast and stem cell differentiation and growth. These more rigid hybrid nano-composites are predicted to possess improved mechanical strength overcoming the mechanical weaknesses of traditional hydrogels clinically utilized for bone regeneration.

Preparation of a thickness-controlled Mg-MOFs-based magnetic graphene composite as a novel hydrophilic matrix for the effective identification of the glycopeptide in the human urine.

The highly effective analysis of glycopeptides from complex biological samples is an attractive and critical topic all the time. In this study, a novel thickness-controlled hydrophilic Mg-metal organic frameworks (Mg-MOFs) coating-functionalized magnetic graphene composite (MagG@Mg-MOFs-1C) was prepared for the capture of the glycopeptides. The as-synthesized composite exhibits an ultralow limit of detection (0.1 fmol μL-1), a perfect size-exclusion effect (HRP digests/BSA protein/HRP protein, 1 : 500 : 500, w/w/w), and a high binding capacity (150 mg g-1), satisfying reusability and high recovery in the recognition of glycopeptides due to its outstanding characteristics including strong magnetic property, large surface area (617 m2 g-1), plenty of affinity sites, and excellent hydrophilicity. Furthermore, the MagG@Mg-MOFs-1C composite was successfully applied to selectively enriched glycopeptides in human urine. More excitingly, 406 N-glycosylation peptides corresponding to 185 glycoproteins were identified in the urine of the bladder cancer patients, in which these identified glycoproteins include the potential biomarkers (α-2-macroglobulin, complement C4-B, and α-1-antitrypsin) for the bladder cancer. This study suggests that the hydrophilic porous MOFs-functionalized composite has a great potential in the large-scale characterization of the low-abundance biomolecules in urine, opening a new avenue for the rapid and convenient diagnosis of the disease.

TiO2-alginate composite aerogels as novel oil/water separation and wastewater remediation filters

Developing effective and “green” approaches to handle aquatic pollution problems is currently one of the most important research subjects of environmental remediation. In this paper, an environmentally friendly, low cost, self-cleaning, highly stable and multifunctional TiO2 enhanced Sodium alginate composite (SAT) aerogel for oil-water separation is developed via a simple combined ionic cross-linking and freeze drying method. The morphological, structural and surface chemical properties of the as-prepared SAT aerogels is characterized by scanning electric microscopy (SEM), X-ray diffraction (XRD), Flourier transformation infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The characterizations demonstrate that the SAT aerogel is of three-dimensional porous microstructure with uniformly dispersed TiO2 nanoparticles (NPs) on alginate matrix. The hydrophilic alginate matrix combined with this unique morphostructure will ensure the SAT aerogels with underwater oleophobicity and subsequent excellent oil/water separation efficiency (up to 99.7%). Moreover, the firmly attached TiO2 NPs can also endow the aerogel with better UV-aging resistance, photoinduced self-cleaning and environmental remediation performance. The SAT aerogel exhibits better oil/water separation reusability (at least 60 cycles) compared to SA aerogel and excellent photocatalytic performance for methyl orange (MO) degradation (>85% after 6 times repeated use). The “green” facile fabrication process, excellent oil/water separation, photoinduced self-cleaning and reusable performances make the SAT aerogel promising for practical application in aquatic environments. This work may open up new avenues for designing versatile aerogel for wastewater remediation.

Development and Evaluation of Ondansetron Orally Disintegrating Tablets

Orally disintegrating tablet (ODT) has number of advantages like faster onset of action, ease of administration, rapid disintegration and dissolution etc. A novel attempt has been made to develop orally disintegrating tablets of Ondansetron by using two approaches, one is soluble hydrophilic matrix by superdisintegrant and other is effect of sweetener on the formulation. Direct compression method was employed for making orally disintegrating tablets. The formulated orally disintegrating tablets have rapid disintegration property for better patient compliance. Formulated tablets were evaluated for physical parameters along with wetting time, disintegration time, drug content and “in vitro” dissolution. In first approach it was found that batch F7 containing Crospovidone (Polyplasdone XL 10) 10 mg showed minimum disintegration time (i.e. approx. 7.00 seconds) with maximum drug release. Wetting time for batch F7 was found to beminimum (i.e. 12 seconds). In second approach of selection of sweetener batch F 10 containing Sodium saccharin was found better in terms of Impurity study (Relative Substances study).Impurity was found within the specified limit compared to other two sweeteners. Stability study was carried out on optimized formulation. Overall batch containing 10 mg Crospovidone (Polyplasdone XL 10) along with Sodium Saccharin was foundstable both physically and chemically.

Preparation and drug release property of tanshinone IIA loaded chitosan-montmorillonite microspheres

In this study, a biocompatible chitosan/montmorillonite (CS/MMT) composite microsphere was developed as a carrier for loading and sustained-release of the hydrophobic drug of tanshinone IIA. Though the compatibility between hydrophobic drugs and hydrophilic matrix was fairly poor, tanshinone IIA was successfully loaded on the microsphere by the solvent exchange process during chitosan matrix dehydration. The microstructure of the resulting microspheres was characterized with several techniques, such as X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM). The results of drug loading and in vitro release study of the tanshinone IIA loaded CS/MMT composite microspheres showed that the incorporation of MMT into CS matrix would enhance the drug encapsulation and retard drug migration. The sample with mass ratio of CS: MMT (10:2) exhibited highest encapsulation efficiency (48.18% ± 2.54%) and slowest continuous cumulative release of drug in phosphate buffer solution (pH 7.4). It was found that the tanshinone IIA release kinetics fit the Higuchi model and the release mechanism was non-Fickian diffusion. Cell viability studies by CCK-8 assay showed that the microspheres showed no obvious cytotoxicity at the dosages below 80 μg/ml, and the MMT content had no significant effect on cell viability. This work provided a successful method of incorporating hydrophobic drugs into hydrophilic matrices, and has been successfully applied to the preparation of effective and biocompatible drug delivery for tanshinone IIA.

Formulation development and Stability Studies of Meropenem Extended-Release matrix Tablets

The aim of this research was to develop a new hydrophilic matrix system containing meropenem (MEX). Extended-release tablets are usually intended for once-a-day administration with benefits to the patient and lower discontinuation of the therapy. Formulations were developed with hydroxyl propyl methyl cellulose or poly (ethylene oxide) as hydrophilic polymers, with different molecular weights (MWs) and concentrations (20 and 30%). The tablets were found to be stable (6 months at 40 ± 2°C and 75± 5% relative humidity), and the film-coating process is recommended to avoid MEX photo-degradation. The dissolution profiles demonstrated an extended-release of MEX for all developed formulations. Dissolution curves analyzed using the Korsmeyer exponential equation showed that drug release was controlled by both drug diffusion and polymer relaxation or erosion mechanisms. A more erosion controlled system was obtained for the formulations containing lower MW and amount of polymer. With the increase in both MW and amount of polymer in the formulation, the gel layer became stronger, and the dissolution was more drug-diffusion dependent. Formulations containing intermediate MW polymers or high concentration (30%) of low MW polymers demonstrated a combination of extended and complete in vitro drug release. This way, these formulations could provide an increased bioavailability in vivo.

Matéria Evaluation of zinc oxide nanoparticles influence on hydrophilic polymer matrix systems

Hydrophilic polymer matrix systems (HPMSs) are a highly relevant tool for drugs delivery whose bioavailability is impaired by low hydrosolubility. Besides this, when associated with nanoparticles these systems can provide better control over release profile of the active drug, maintaining the posology. Since polyvinylpyrrolidone (PVP) and zinc oxide (ZnO) are safe materials for use in the human body, we studied the effects of ZnO nanoparticle ratios on the characteristics of PVP matrix. For that purpose, nanocomposites were prepared by solution casting method and characterized by X-ray Fluorescence (XRF), Fourier Transform Infrared (FTIR), Thermal Gravimetric Analyses (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XDR) and Low-field Nuclear Magnetic Resonance (LF-NMR) technique, using relaxometry. We also analyzed the effects of the system on two broad-spectrum antimicrobial drugs. The characterization results of the new materials indicate good interaction of the nanoparticles with the polymer, and this fact suggests that these new materials may have a retarding effect on drug release. The results also showed no disruptive interaction of the matrix system important to the action of the antimicrobials. Keywords: Polymer, Nanotechnology, Drug delivery, ZnO.

Effect of novel internal structures on printability and drug release behavior of 3D printed tablets

Semi-solid extrusion (SSE) 3D printing is an innovative and promising method that is suitable for the fabrication of personalized dosage forms of tablets. The aim of this study is to develop and evaluate the effectiveness of SSE 3D printed tablets with novel internal structures. Twelve types of 3D printed tablets with pre-designed structures were developed. Glipizide was selected as the model drug and three different concentrations of the HPMC K100LV polymer were used in the 3D printing process as the hydrophilic matrix. All of the printed tablets had satisfactory physical properties and structural integrity indicating the suitability of SSE 3D printing for the fabrication of personalized medicines with complex structures. The dissolution profiles of the printed tablets revealed the relationship between novel structures and drug release behavior. Tailored drug release may be easily achieved without changing the prescription by adjusting printing parameters such as outline value, grid width and printing pattern. All results of this paper clearly reveal the feasibility and capability of SSE 3D printing technology as a novel pharmaceutical manufacturing technique to fabricate personalized medicines and modulate drug dissolution profiles.