Hydroxypropyl Cellulose Research Articles

Selection of structure-induced aptamer targeting small molecule based on capillary sieving electrophoresis.

In this study, a structure-induced aptamer targeting small molecules was selected using capillary sieving electrophoresis (CSE). CSE was conducted using a capillary filled with a background solution containing hydroxypropyl cellulose as a sieving matrix to separate the aptamer candidates by changing their structures via complexation. Before aptamer selection, the original random-sequence DNA library was used to create structure-not-preorganized DNA sub-library containing straight-chain-like structures using CSE. Next, a structure-induced aptamer targeting L-tyrosinamide was selected from the prepared sub-library. Six aptamer candidates were selected, one of which showed a binding ability comparable to that of the reported L-tyrosinamide aptamer and selectivity toward the analogs. These results indicated that the proposed method can be applied to select structure-induced aptamers that target small molecules.

A sustainable utilization approach of waste biomass resources to smart materials for buildings

Resource utilization of solid waste promotes resource conservation, energy transformation and sustainable development. In this study, we developed a synthetic strategy for converting biomass waste, such as waste bamboo powder, into a smart material with thermochromic properties - hydroxypropyl cellulose (HPC). The synthesis process includes extraction of cellulose and modification with hydroxypropyl groups. The maximum extraction efficiency of cellulose from raw bamboo powder was up to 48 % by carefully adjusting the reaction conditions including NaOH concentration, reaction time, and treatment temperature. The maximum yield of modification process was achieved to 1.32 g/g by optimizing alkalization temperature, alkalization time, NaOH concentration, propylene oxide concentration, etherification temperature and etherification time. The samples were characterized by a variety of techniques such as FTIR, 1H NMR, XRD, SEM to validate the micro-structure of the extracted cellulose the HPC materials. Moreover, this study explored the potential application of HPC hydrogel in smart window application, and evaluated its building energy saving efficiency under different climate conditions through computational simulation. The corresponding results showed that the HPC hydrogel smart window could have significant energy saving potential compared to ordinary clear glass window. This novel approach of converting waste resources into high valued thermochromic materials for smart windows, not only reduces waste disposal demand for excessive land-use and energy consumption but also shows a positively contributes to sustainable development, environmental protection, as well as energy conservation.

Geometry-Driven Fabrication of Mini-Tablets via 3D Printing: Correlating Release Kinetics with Polyhedral Shapes.

The aim of this study was to fabricate mini-tablets of polyhedrons containing theophylline using a fused deposition modeling (FDM) 3D printer, and to evaluate the correlation between release kinetics models and their geometric shapes. The filaments containing theophylline, hydroxypropyl cellulose (HPC), and EUDRAGIT RS PO (EU) could be obtained with a consistent thickness through pre-drying before hot melt extrusion (HME). Mini-tablets of polyhedrons ranging from tetrahedron to icosahedron were 3D-printed using the same formulation of the filament, ensuring equal volumes. The release kinetics models derived from dissolution tests of the polyhedrons, along with calculations for various physical parameters (edge, SA: surface area, SA/W: surface area/weight, SA/V: surface area/volume), revealed that the correlation between the Higuchi model and the SA/V was the highest (R2 = 0.995). It was confirmed that using 3D- printing for the development of personalized or pediatric drug products allows for the adjustment of drug dosage by modifying the size or shape of the drug while maintaining or controlling the same release profile.

Thermo-responsive circularly polarized luminescence from carbon quantum dots in a cellulose-based chiral nematic template

Abstract Circularly polarized light emitting active materials are of great interest, and the convenient tuning of the circularly polarized luminescence (CPL) remains a significant challenge. Integrating fluorescent materials into chiral photonic crystals to achieve tunable CPL is a promising approach, allowing efficient manipulation of CPL by adjusting the photonic band gap (PBG). We combined carbon quantum dots (CQDs) with hydroxypropyl cellulose (HPC), which self-assembles into a cholesteric liquid crystal (CLC). The helical structure can selectively reflect right circularly polarized (RCP) light, achieving strong circular dichroism (CD) and high CPL dissymmetry factor g lum. In addition, the chiral template is thermo-responsive. The CPL wavelength can be adjusted by regulating the PBG position through temperature adjustment, while the chirality of CPL keeps high especially in the heating process. This work enables stimuli-responsive manipulation of CPL under one template through temperature regulation, which may open up enormous possibilities for the cellulose-based material in different areas.

Determination of the degree of molar substitution of hydroxypropyl cellulose by gas chromatography

Abstract We have improved the gas chromatography (GC) method with the aid of 1H NMR to determine the degree of molar substitution (MS) of hydroxypropyl cellulose (HPC). This improvement relied on our established dissolution approach for low-substituted HPC, facilitating NMR determination and subsequently expanding the working range of the MS determination from the lower limit of USP specified as 53.4% to 9.3% (MS 0.2). In this method, 2-iodopropane was produced by the reaction of hydroiodic acid with HPC at high-temperature and then measured by GC. 1H NMR was used for the correction of GC method. The MS results via the GC method (MSGC) exhibited a linear correlation with those obtained by the 1H NMR method (MSNMR), with correction equation of MSNMR=1.8026MSGC - 0.2046 (R2 = 0.9979). Method validation results showed that the average recovery and relative standard deviation (RSD) of MS are 103.5% and 0.83%, respectively. Detection limit and quantitation limit were 0.08 and 0.26, respectively. This method is accurate, sensitive with good precision, which is of great value for the production, research and development, and application of HPC, particularly the low-substituted HPC.

Evidence of a Rod-like Structure for Hydroxypropyl Cellulose Samples in Aqueous Solution.

Because hydroxypropyl cellulose (HpC) is a popular polymeric material that forms a liquid crystalline phase in solutions with various kinds of solvents, including water, it is commonly thought that HpC has a typical rod-like structure in solution. In this study, the structures of commercial HpC samples in aqueous solution with average molar substitution numbers (MS) ranging from 3.6 to 3.9 and weight-average molar masses (Mw) ranging from 36 to 740 kg mol-1 were investigated in detail. We first used multiple techniques, including standard static and dynamic light scattering (SLS and DLS), neutron and X-ray scattering experiments, and viscometric measurements, to obtain clear evidence of rod-like structures quantitatively. The dependence of excess scattering intensities for HpC samples under dilute conditions on the magnitude of the scattering vector over a wide range from 8.9 × 10-3 to 3.0 × 10 nm-1 was reasonably described by the form factor of rod particles with length (L) and diameter (d). Although the determined L value was close to the contour length (lc) calculated from the Mw values in the lower Mw range, L became obviously less than lc with increasing Mw. The radius of gyration (Rg) determined via SLS measurements was proportional to L by a factor of approximately 3.5 ∼ √12 over the Mw range examined. These observations revealed that the conformation of HpC molecules changes from an elongated single chain to a certain folded structure, maintaining the shape of the rod-shaped particles. Moreover, the Mw dependencies of the intrinsic viscosities and translational diffusion coefficients of the HpC samples resulting from DLS measurements were reasonably described with a theoretical rod-like particle model, assuming that L and d are identical to those resulting from the scattering behaviors.

Development and assessment of immediate-release tablets containing clopidogrel bisulphate & aspirin-strategy for optimizing the combination formulation.

The main goal of the study was to improve the compliance and convenience of patients by designing and development of an immediate release (IR) fixed-dose combination (Clopidogrel bisulphate and Aspirin) tablets. The proposed combination product utilizes Clopidogrel to protect the moisture-sensitive aspirin component, enhancing its stability against atmospheric conditions. Response-surface approach (Design Expert vs. 13) was used to generate this IR tablet by calculating the right composition of independent variables such as Microcrystalline cellulose 102, pregelatinized starch and Hydroxypropyl cellulose. 32 factorial design was used to estimate the effects of these independent variables on the responses of dependent variables (disintegration & friability) and constructed a total of nine (9) formulations. Pre and Post formulation, quality control parameters were investigated as per pharmacopeia. A systematic approach was used for the optimization process and a prototype checkpoint batch (CPB) based on the better contrast of independent variables was prepared. In vitro analysis of formulations was carried out to estimate the responses. Friability was found in the range of 0.088-1.076%w/w, except F1 = 1.076 all are within limits (NMT 1.0%). Disintegration time was recorded 7.3 ± 1.20 as lower and 24.5 ± 1.63 min was the highest. The release of drugs from their dosage form was fast and rapid, for clopidogrel after 15min was 70.42-96.82% with SD ± 8.71 and aspirin was 69.88-91.49% in 15 min with SD ± 6.41, all the tablets were released more than 80% in 20 min. The stability outcomes of CPB tablets after 15 days of stress study (60 ± 2°C and 75 ± 5%) indicated good compatibility and stability of APIs with excipients. It was concluded that the direct compression method can be preferred to prepare a combination product with cost-effectiveness. It was also concluded that the proposed methodology could increase Aspirin's stability and allow for an aqueous coating system to finish the product with a film coating. By using Design Expert software, the best composition of the formulation can be selected and optimized in a short period of time with minimum trial and errors. The results also demonstrated that the use of a fixed-dose combination tablet instead of the individual is expected to be more convenient to patients and thus improves patient compliance and decreases the occurrence of adverse effects and side effects.

Dynamic covalent bonds of hemiacetals and acetals enables reprocessability and raw material recyclability of high performance cellulosic thermosetting resins

Despite covalent adaptable networks (CANs) imparting the reprocessing performance of crosslinked polymers, due to reversible bond exchange of the dynamic covalent bonds; it is still a huge challenge to design catalyst-free, fast reprocessing, controlled degradation and raw material recycling biomass base CANs. Here, for the first time, we prepared cellulose CANs base on hemiacetal and acetal bonds (ACCs) via aldehyde and hydroxyl reaction of the dialdehyde crosslinker with hydroxypropyl cellulose (HPC). By regulating the crosslink density and chemical structure of the crosslinked network, ACCs exhibit tunable thermal and mechanical properties. The crosslinked network structure of the ACCs benefits from the rapid bond exchange of the hemiacetal and acetal bonds at elevated temperatures, which allows for rapid stress relaxation and thus, superior reprocessing properties. In addition, it was found that the dynamic exchange of acetals in the ACCs is influenced by the chain length and flexibility of the crosslinker. Moreover, ACCs possess good degradation and cellulose feedstock recycling properties due to the acid sensitivity of the acetal bonds. This work provides an effective solution to the problems of resource waste caused by petroleum-based thermoset plastics.

Analysis and Compensation of Hydroxypropyl Cellulose Sensors Degradation in Force Assessment Applications

Analysis and Compensation of Hydroxypropyl Cellulose Sensors Degradation in Force Assessment Applications

Multifunctional composite flexible films of hydroxypropyl cellulose and silver nanowires

Flexible wearable devices have aroused attentions since the booming flexible electronic technologies, as well as the requirements for improved comfortableness and real-time monitoring for complex motion state of human body. Developing a flexible integrated wearable device with multi functions provides a promising route for next-generation wearable devices. Meanwhile, transparency and biocompatibility are also considered a lot. Herein, hydroxypropyl cellulose/silver nanowires (HPC/AgNWs) flexible composite films were fabricated with a facile two-step method. The fabricated composite films exhibited sufficient transparency and mechanical strength. More importantly, the HPC/AgNWs composite films afforded good motion sensing performances with current sensitivity as high as 350 %. It can accurately identify different bending angles and frequencies, and remained stable for more than 1000 bending cycles. Apart from being employed as motion sensors, the fabricated HPC/AgNWs could be also used for electrical heating and electromagnetic shielding. The films could be heated to more than 60°C at 3.0 V in 57 seconds, and the electromagnetic shielding efficiency reached more than 99.9 %. This study contributed a feasible strategy for the preparation of multifunctional flexible films which are expected to be further applicated in the field of wearable devices.

Evaluation of binders in twin-screw wet granulation – Optimization of tabletability

The influence of hydroxypropyl cellulose type (HPC-SSL SFP, HPC-SSL), concentration (2 %, 3.5 %, 5 %) and filler (lactose, calcium hydrogen phosphate (DCP)/microcrystalline cellulose (MCC)) on twin-screw wet granulation and subsequent tableting was studied. The aim was to identify the formulation of the highest tabletability which still fulfills the requirements of the disintegration. Lactose combined with 5 % binder enabled a higher tabletability and a faster disintegration than DCP/MCC. It was found that tabletability of lactose formulations can be increased by higher binder concentration and higher compression pressure while tabletability of DCP/MCC formulations can be only increased by higher compression pressure. It was observed that batches containing DCP/MCC failed the disintegration test, if the highest binder concentration and the highest compression pressure were used. To ensure a fast disintegration, the compression pressure or at least the binder concentration had to be low. Changing the disintegrant and its localization improved the DCP/MCC formulation, resulting in faster disintegration than lactose tablets. However, it also resulted in a lower tabletability. In this study best tablets were achieved with 3.5 % or 5 % binder and lactose as filler. These tablets presented the highest tabletability but still disintegrated in less than 500 s.

Sustainable, super-stable thermochromic material by coupling hydroxypropyl cellulose and sodium carboxymethyl cellulose

Hydroxypropyl cellulose (HPC) is a green thermochromic material in energy-saving buildings, anti-counterfeiting, and data security fields. However, the high lower critical solution temperature (LCST) of HPC, around 42 °C (higher than the human thermal comfort temperature), limits its thermochromic sensitivity, poor stability, and short lifespan. Herein, we developed a durable, high-performance cellulose-based thermochromic composite with a lower LCST and easy preparation capability by combining HPC with sodium carboxymethyl cellulose (CMC). In such thermochromic cellulose, CMC constructs a hydrophilic skeleton to enable uniform dispersion of HPC, and functions as a stronger competitor to attract the water molecules compared to HPC, both of which trigger high thermochromic sensitivity and low LCST (just 32.5 °C) of our CMC/HPC. In addition, CMC/HPC shows superior stability, such as 100-day working capability and 60-time recyclability. This advancement marks a significant step forward in creating sustainable, efficient thermochromic materials, offering new opportunities for energy conservation in the building.

Triple-Responsive, Multimodal, Visual Electronic Skin toward All-in-One Health Management for Gestational Diabetes Mellitus.

Gestational diabetes mellitus (GDM) is one of the most common metabolic disorders during pregnancy, leading to serious complications for pregnant women and a threat to life safety of infants. Therefore, it is particularly important to establish a multipurpose monitoring pathway to important physiological indicators of pregnant women. In this work, three kinds of double network hydrogels are prepared with poly(vinyl alcohol) (PVA), borax, and cellulose ethers with varying substituents of methyl (methyl cellulose, MC), hydroxypropyl (hydroxypropyl cellulose, HPC), or both (hydroxypropyl methyl cellulose, HPMC), respectively. The corresponding toughness (143.9, 102.3, and 135.9 kJ cm-3) and conductivity (0.69, 0.45, and 0.51 S m-1) of the hydrogels demonstrate that PB-MC was endowed with the prominent performance. Molecular dynamics simulations further revealed the essence that hydrogen bond interactions between PVA and cellulose ethers play a critical role in regulating the structure and properties of hydrogels. Thermochromic capsule powders (TCPs) were subsequently doped in to achieve a composite hydrogel (TCPs@PB-MC) to indicate the change in human body temperature. Furthermore, the process of the TCPs@PB-MC response to glucose, pH, and temperature was tracked in-depth through the electrochemical window. This work provides a novel strategy for all-in-one health management of GDM.

The potential of new eco-friendly formulations in enhancing the protection of ceramic artifacts

This study focuses on transforming the consolidation formulations based on Hydroxypropyl cellulose (HPC), which is an eco-friendly bio-based cellulosic polymer with inherent hydrophilic characteristics to a hydrophobic one. This will be done via integrating the polymer with nano-silica and hydrophobic nano-silica, to enhance its consolidating properties to be in line with the global trend of replacing conventional materials with eco-friendly alternatives. Three different formulations were prepared, including HPC polymer solely, HPC integrated with nano-silica (NS), and HPC integrated with hydrophobic nano-silica (HNS). Primarily, nano-silica and hydrophobic nano-silica were synthesized and characterized using TEM and XRD. Subsequently, the prepared formulations were applied to artificial ceramic artifacts to evaluate their physical and mechanical properties, encompassing parameters such as water absorption, color change, contact angle, SEM/EDX, and digital microscopy. The results revealed that the incorporation of hydrophobic nano-silica significantly enhanced the mechanical and the physical properties of the cellulosic polymer, besides the extreme change that happened to its hydrophilic properties which was developed to a very good hydrophobic one. The success of these consolidation formulations can pave the way for the utilization of bio-based polymers with their inherent eco-friendly nature in the consolidation and restoration processes of cultural heritage artifacts, which can help in the contribution to the expanding body of knowledge in sustainable materials for conservation purposes.

Preparation of Gel Forming Polymer-Based Sprays for First Aid Care of Skin Injuries.

Currently, there are several types of materials for the treatment of wounds, burns, and other topical injuries available on the market. The most used are gauzes and compresses due to their fluid absorption capacity; however, these materials adhere to the surface of the lesions, which can lead to further bleeding and tissue damage upon removal. In the present study, the development of a polymer-based gel that can be applied as a spray provides a new vision in injury protection, respecting the requirements of safety, ease, and quickness of both applicability and removal. The following polymeric sprays were developed to further obtain gels based on different polymers: hydroxypropyl cellulose (HPC), polyvinyl pyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC) using polyethylene glycol (PEG) as a plasticizer. The developed sprays revealed suitable properties for use in topical injuries. A protective film was obtained when sprayed on a surface through a casting mechanism. The obtained films adhered to the surface of biological tissue (pig muscle), turning into a gel when the exudate was absorbed, and proved to be washable with saline solution and contribute to the clotting process. Moreover, biocompatibility results showed that all materials were biocompatible, as cell viability was over 90% for all the materials.

Effect of hydroxy propyl cellulose grade and foam quality on foam granulation of a high drug load formulation

Foam granulation is a relatively newer wet granulation process whereby foamed binder solutions are added to the powders in the mixer to reduce localized over-wetting encountered during the wet granulation. This study is the first to investigate the effect of binder grade and foam quality on foam granulation process and granule properties of a high drug load formulation. Two different HPC grades, HPC LF (two times more viscous) and HPC EXF at an equivalent 7.4%w/w solution concentration, and foam quality of 50%, 90% and binder solution dripped were added to a high drug load (81%w/w) formulation for wet granulation. The granules were evaluated for compactibility and resultant compact strengths. The 50% foam quality of either HPC LF and HPC EXF resulted in lowest impeller power reading and water activity compared to 90% foam quality or dripped HPC solution. Granules prepared with 50% foam quality also exhibited smaller granule size, wider size distribution and higher specific surface area, resulting in higher compactibility. Whilst the granules prepared with different foamed HPC grades were not significantly different in compression behavior, they were higher in compact strengths, suggesting that foam mixing was more efficient in binder distribution compared to binder liquid penetration and distribution.

Controlled micro-scale ink droplet spreading on cotton fabrics via cellulose-based coatings for greener textile inkjet printing

Inkjet printing of cotton fabric is considered a cleaner, efficient and revolutionary technology in textile coloration industry. However, due to the good hydrophilicity of cotton fibers, ink droplet spreading was difficult to be prevented, causing the problems of poor image resolution, low dye utilization efficiency and reduced product quality. Hence, in this study, cellulose-based coatings were fabricated on the cotton surface to adjust the surface hydrophilicity and prevent ink droplet spreading. Results showed that, cellulose derivatives like hydroxypropyl cellulose (CMHPC) and hydroxyethyl methyl cellulose (HEMC) could form continuous and uniform cellulose film coatings on fiber surface. Because there are fewer hydrophilic side groups in HEMC structure, the hydrophilicity of cotton fabric and the ink spreading was effectively controlled. From microscope observation, the spreading lengths of a single droplet were significantly decreased by HEMC from 276.27 to 66.95 μm. The K/S values representing color depth were improved from 9.44 to 19.41. Furthermore, industrial application was conducted to verify the laboratory results, showing that higher image quality was obtained in practical application using HEMC. This work provides a more potential and greener application of cellulose-based coatings to promote the development of textile inkjet printing.

Consolidation materials used with illuminated and non-illuminated paper manuscripts and historical leather bindings: a review

Purpose This study aims to focus on the main materials used in consolidation processes of illuminated paper manuscripts and leather binding. Design/methodology/approach For each material, chemical structure, chemical composition, molecular formula, solubility, advantages, disadvantages and its role in treatment process are presented. Findings This study concluded that carboxy methyl cellulose, hydroxy propyl cellulose, methyl cellulose, cellulose acetate, nanocrystalline cellulose, funori, sturgeon glue, poly vinyl alcohol, chitosan, chitosan nanoparticles (NPs), gelatin, aquazol, paraloid B72 and hydroxyapatite NPs were the most common and important materials used for the consolidation of illuminated paper manuscripts. For the leather bindings, hydroxy propyl cellulose, polyethylene glycol, oligomeric melamine-formaldehyde resin, acrylic wax SC6000, pliantex, paraloid B67 and B72, silicone oil and collagen NPs are the most consolidants used. Originality/value Illuminated paper manuscripts with leather binding are considered one of the most important objects in libraries, museums and storehouses. The uncontrolled conditions and other deterioration factors inside the libraries and storehouses lead to degradation of these artifacts. The brittleness, fragility and weakness are considered the most common deterioration aspects of illuminated paper manuscripts and leather binding. Therefore, the consolidation process became vital and important to solve this problem. This study presents the main materials used for consolidation process of illuminated paper manuscripts and leather bindings.

Topical Meloxicam Hydroxypropyl Guar Hydrogels Based on Low-Substituted Hydroxypropyl Cellulose Solid Dispersions.

Meloxicam (MX) is a poorly water-soluble drug with severe gastrointestinal side effects. Topical hydrogel of hydroxypropyl guar (HPG) was formulated using a solid dispersion (SD) of MX with hydroxypropyl cellulose (LHPC) as an alternative to oral administration. The development of a solid dispersion with an adequate MX:LHPC ratio could increase the topical delivery of meloxicam. Solid dispersions showed high MX solubility values and were related to an increase in hydrophilicity. The drug/polymer and polymer/polymer interactions of solid dispersions within the HPG hydrogels were evaluated by SEM, DSC, FTIR, and viscosity studies. A porous structure was observed in the solid dispersion hydrogel MX:LHPC (1:2.5) and its higher viscosity was related to a high increase in hydrogen bonds among the -OH groups from LHPC and HPG with water molecules. In vitro drug release studies showed increases of 3.20 and 3.97-fold for hydrogels with MX:LHPC ratios of (1:1) and (1:2.5), respectively, at 2 h compared to hydrogel with pure MX. Finally, a fitting transition from zero to first-order model was observed for these hydrogels containing solid dispersions, while the n value of Korsmeyer-Peppas model indicated that release mechanism is governed by diffusion through an important relaxation of the polymer.

CONSERVATION OF A PAINTED WOODEN COFFIN AT DAHSHUR ARCHAEOLOGICAL AREA

This paper aims to document the conservation processes of a polychrome wooden coffin in the Dahshur archaeological area dating back to the late period. The exterior part of the coffin is decorated with a painted layer. Visual observation, 2D Program, and Optical Microscopy (OM) were used. wood identification. The coffin was in a bad condition. It was covered with a thick layer of dust, losing parts of the painted and gesso layers, as well as other parts of these layers, were lost. Some parts were missing from the head area of the lid coffin. The conservation processes of the wooden coffin included mechanical and chemical cleaning, reattachment of the separated parts of the ground layer and painted layers, filling the edge of the painted layer, and consolidating the painted layer. The conservation process included mechanical cleaning using soft brushes, chemical cleaning using ethyl alcohol and distilled water for painting, stabilization of the separated gesso layer using Paraloid B72, filling cracks of the gesso layers using glass microballoon with Paraloid B72 and consolidating the painted layer with calcium oxide nanoparticles with Klucel G (hydroxypropyl cellulose) 0. 5%