Structural and Mechanical Investigation of Hydroxypropyl Methyl Cellulose Addition to Mortar

Edible oleogels are prepared by different kinds of hydroxypropyl methyl cellulose (HPMC) and methylcellulose (MC) through emulsion‐templated method. Physical properties of the oleogels such as rheological behavior and oil binding capacity are evaluated. Polarizing light microscopy (PLM) as well as scanning electron microscopy (SEM) are used to gain information on the microstructure of the samples. Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) are used to evaluate intermolecular forces between the polysaccharides in the oleogels. It is found that oil‐water interface layers of the emulsions are strengthened by polysaccharides (HPMC and xanthan gum [XG] or MC and XG), and it prohibits oil droplets from coalescing during drying. The formation of semi‐crystalline structure of oleogels to trap the oil is attributed to intramolecular/intermolecular hydrogen bonding between the polysaccharides. The higher viscosity grade results in better structure with respect to emulsions, vacuum dried emulsions, and oleogels compared to that of lower viscosity grade for HPMC or MC. The mechanical strengths of vacuum dried emulsions and oleogels stabilized by HPMC are harder compared to that of MC. The study will provide guidance for the production of functional fat products with zero trans and low saturated fatty acids.Practical Applications: HPMC and MC, two types of dietary fiber, are two kinds of the most commonly used cellulose ethers which are food‐approved additives. The oleogels prepared by HPMC and MC using an emulsion‐templated method can be used to produce functional fat products with zero trans and low saturated fatty acids, which will be beneficial to human health. The properties of oleogels structured by different HPMC and MC with the different degree of polymerization (DP) and substitution (DS) are different. The physical properties, microstructure, and intermolecular forces for oleogels are evaluated in order to lay the basis for the application of the oleogels.A schematic representation of the structure of oleogels stabilized by hydroxypropyl methyl cellulose (HPMC) and xanthan gum (XG).

Introduction. Thioctic acid is used in the treatment of diseases that are characterized by lack of mitochondrial activity, which is responsible for the formation of free radicals. Widespread use of thioctic acid is due to the chemical structure. The thioctic acid exhibits biological activity in both hydrophilic and hydrophobic environments. Thioctic acid is an enzyme cofactor and a powerful antioxidant, it regulates the transcription of numerous genes, participates in regulation of glucose and lipid metabolism, increases insulin sensitivity, and forms complexes with heavy metals. Thioctic acid has a high pharmacological potential, which is confirmed by the evidence base of clinical trials. An analysis of the literature on the oral use of thioctic acid indicates that solid dosage forms can be used for long-term therapy. This route of administration is limited by factors such as reduced solubility in acidic environments and enzymatic degradation. For this reason, the search for various compositions of auxiliary substances and methods of obtaining drugs is an urgent task of pharmaceutical technology. Material & methods. Objects of study were solid dispersions of thioctic acid (SDTA) on the basis of cellulose derivatives: microcrystalline (MCC), HPMC (hydroxypropyl methylcellulose) and polyvinylpyrrolidone (PVP) as compared to thioctic acid (TA). The samples were made by solid phase method using micronization in a laboratory shredder at a ratio of 1: 1. Pharmacological and technological parameters were determined according to generally accepted methods. Results & discussion. In appearance the resulting mixtures had lemon color, without inclusions and the formation of conglomerates, with homogeneous sized particles According to the pharmaco-technological studies, the samples do not have a satisfactory flowability. The values of the Carr index and the ratio of Hausner make it possible to conclude that there is a large force of cohesion between the particles, a significant aeration of the material. As can be seen from the data presented in the table, micronization in the medium of MCC, PVP and HPMC has led to a change in the density of stacking, which is characteristic of powders with an anisodiametric form of particles, but the strength of the internal friction coefficient has practically not changed, as evidenced by the indicators of the natural slope. The value of porosity suggests a significant degree of the Van der Waals forces action between the particles of the SD. All samples of solid dispersions can be attributed to fragile materials: BW was 5.57 kgf / mm2. When stored in a static state, there was a partial agglomeration. The results show that all samples of solid dispersions are well moistened with purified water, as opposed to a sample of tioctic acid. An analysis of the marginal wetting angle indicates that the surfaces of samples of solid dispersions are hydrophilic. According to the microscopic analysis it was established that the influence of external forces has changed the form of the thioctic acid: from the plate with the factor of the form 0,85 to the uncertain form. In samples with microcrystalline cellulose and hydroxypropyl methylcellulose there is a mixture of crushed thioctic acid crystals and carrier. The form factor has dropped to 0.45. The investigation of the dissolution of the obtained solid dispersions showed that the addition of MCC to thioctic acid even reduces the amount of matter passing into the solution, as opposed to solid dispersions with PVP and HPMC (24% and 37% respectively). The difference in the values of dissolution can be due to both the nature of chemical bonds, and the nature of electrostatic attraction, due to the polarity and the emergence of hydrogen bridges. The investigation of the dissolution of the obtained solid dispersions showed that the addition of microcrystalline cellulose to thioctic acid even reduces the amount of matter passing into the solution, as opposed to solid dispersions with PVP and HPMC. The difference in the values of dissolution can be due to both the nature of chemical bonds, and the nature of electrostatic attraction, due to the polarity and the emergence of hydrogen bridges. Conclusion. Thus, the results indicate an increase in the dissolution of thioctic acid in the solid dispersion with PVP in 2.6 times, with HPMC in 1.3 times, which may be the basis for research on the development of solid dosage forms of thioctic acid.

The purpose of this study was to investigate the interaction between a nonionic polymer, (hydroxypropyl)methyl cellulose (HPMC), and cationic gemini surfactants, bis(hexadecyldimethylammonium)hexane dibromide (16-6-16), bis(hexadecyldimethylammonium)pentane dibromide (16-5-16), and their corresponding monomeric counterpart cetyltrimethylammonium bromide (CTAB), by using electrical conductometry, fluorescence, and viscometry methods. It was found that the gemini surfactants interact strongly with HPMC as compared to conventional surfactant CTAB. The free energies of aggregation, ΔGagg, micellization, ΔGmic, and transfer, ΔGt, associated with the binding interaction between surfactant and polymer, have also been evaluated. The negative values of ΔGt confirm the feasibility of interaction between the surfactant and polymer. The aggregation number (Nagg) obtained from steady state fluorescence measurement with CTAB was found to be more than with the geminis. A significant viscosity increment was observed in t...

Novel methylcellulose based thermosenstive in situ nano liposomes of docetaxel for improved pharmacokinetics and pharmacodynamics with reduced toxicity

Cellulose ethers such as (hydroxypropyl)methyl cellulose (HPMC), (hydroxyethyl)methyl cellulose (HEMC), methyl ethyl hydroxyethyl cellulose (MEHEC) are currently used admixtures in the production of factory-made mortars. They improve such properties as water retention, workability, adhesion to the substrate, open time etc. in the cement-based mortars. The article investigates the impact of physicochemical properties (molecular weight, methods of modification, viscosity) on water retention, rheological properties and the adhesiveness to the substrates of renovation plasters. The research showed that the cellulose viscosity has a greater impact on water retention despite diversified effects of various derivatives of cellulose. The influence of viscosity of cellulose ethers is uneven. The greatest growth of retention was observed with the change of viscosity from 100 mPa⋅s to 15000 mPa⋅s. The further growth of viscosity of cellulose admixtures influenced the change of water retention with lower intensity. It was also stated that cellulose ethers improve the adhesion of renovation plasters to the substrates. Particularly beneficial results were obtained in the case of plasters consisting (hydroxypropyl)methyl cellulose(HPMC)-based admixtures.

To assess the miscibility and phase behavior of binary blends of hydroxypropylmethyl cellulose (HPMC) with hydroxypropyl cellulose (HPC), methylcellulose (MC), and polyvinylpyrrolidone (PVP). Polymer-polymer miscibility was assessed by measurement of the glass transition temperature (Tg) and the width of the glass transition temperature (W-Tg), using modulated temperature differential scanning calorimetry (MTDSC). HPMC K4M/PVP and HPMC E5/MC blends were miscible as evidenced by a single, composition dependent, Tg throughout the entire composition range. HPMC/HPC blends were immiscible at all compositions. For the miscible blends, the variation in Tg with blend composition was compared to the values predicted by the Fox and Couchman-Karasz equations. At intermediate blend compositions, HPMC K4M/PVP blends exhibited negative deviations from ideal behavior. The Tg of the HPMC E5/MC blends was found to follow the Fox equation. The W-Tg measurements of the miscible blends gave evidence of phase separation at certain compositions. MTDSC was shown to be a useful technique in characterizing the interactions between some commonly used pharmaceutical polymers.

Objective To compare the effects of intraoperative corneal wetting by Croma, balanced salt solution (BSS), and hydroxypropyl methylcellulose (HPMC) on xerophthalmia after cataract surgery. Methods This prospective study included 79 patients (90 eyes) who were randomly assigned to a Croma corneal wetting properties group, balanced salt solution (BSS) group, or domestic hydroxypropyl methylcellulose (HPMC) group. Croma is a ophthalmological product to protect corneal epithelium, whose main ingredients is 2%HPMC. The solutions were applied to the ocular surface during the surgery to keep it moist. The following were measure pre-operatively and at 1, 7, and 30 days after cataract surgery, and the effect of each solution was assessed: objective scatter index (OSI) and the amplitude of OSI (OSI-A), tear break-up time (BUT), corneal fluorescein staining (CFS), Schirmer I test (SIt), and the ocular surface disease index (OSDI) questionnaire scores. Data were analyzed by repeated ANOVA or Kruskal-Wallis test. Results There were significant differences for OSI and SIt among the three groups (P<0.05). For OSI and SIt, the Croma group had significantly better results than the BSS group at post-operative days 1, 7, and 30 (all P<0.05). The Croma group had significantly higher SIt scores for tear secretion than the HPMC group at 7 and 30 days after surgery (P<0.05). Similar changes in trends were discovered with repeated measures analysis. BUT of the three groups all declined and revealed a significant difference among the pre- and post-operative (P<0.05). For the BSS group, several of the measured parameters were worse than the pre-operative values. On post-surgical day 1, SIt and OSI-A were worse (P<0.05 each), subjective complaints were worse on day 7 (P<0.05), and CFS was worse on day 30 (P<0.001). In the HPMC group, SIt and OSI-A increased significantly on post-operative day 1 (P<0.05). In the Croma group, and there was a slight increase in OSI-A and SIt at the same time. Neither CFS nor OSDI scores increased for either the HPMC or the Croma groups. Conclusion Both Croma corneal wetting properties and domestic HPMC were more beneficial than BSS for alleviating xerophthalmia after cataract surgery. The reduction of tear secretion and the increase in corneal epithelial staining were smaller in the Croma group than in the HPMC and BSS groups, and patients had less discomfort. Therefore, the Croma corneal wetting properties were significantly better than the others. Key words: Cataract extraction; Xerophthalmia; Corneal wetting properties; Stability of tear film; Tear secretion

Dissolution rate of an active substance from suppositories may be altered by the qualitative and quantitative selection of suitable excipients. Thus, the accelerated-release or sustained-release suppositories can be manufactured. The objective of our study was to prepare the suppositories containing paracetamol in Novata BD and Novata BCF bases by the fusion method as well as to evaluate the influence of addition of the bioadhesive substances, namely: hydroxypropyl methyl cellulose (HPMC) and methylcellulose (MC) at concentrations of 5, 10, 15 and 20%, on the physico-chemical properties of suppositories. Assessment of the preparations were based on the outcomes of the following tests: uniformity of mass, uniformity of content of active substance, hardness of suppositories, softening time determination and the disintegration time of suppositories. Release of the active substance into the phosphate buffer at pH 7.2 was also performed. Content of the active substance was determined spectrophotometrically at 243 nm. On the basis of the obtained results it may be concluded that the addition of MC at concentrations of 15%, 20% and HPMC at concentrations of 5%, 10%,15%, 20% delays the release of active substance from suppositories. The physical properties of the prepared suppositories met the requirements of the Polish Pharmacopoeia, 9th edition.

Biocompatible poly(vinyl alcohol)/poly (vinylpyrrolidone) iodine/poly(ethylene glycol) fibers containing (hydroxypropyl)methyl cellulose (HPMC) and aloe vera were successfully prepared by electrospinning their aqueous solution. Aloe vera which is known to be effective in the treatment of various wounds was added to the polymer solution. HPMC was added to the system as the water retention agent. The hybrid fiber mats were subjected to detailed analysis using a differential scanning calorimeter, a scanning electron microscope (SEM), and a Fourier transform infrared spectrometer. Images obtained from the SEM showed that the polymer fibers were linear, homogenous, and contained no beading. The fiber diameters ranged between 100 and 900 nm. It was seen that the electrospun mats obtained could potentially be used as a material for dressing wounds. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of hydroxypropyl methyl cellulose and methyl cellulose as technological feed additives for all animal species. In its previous opinions on the safety and efficacy of the products, the FEEDAP Panel could not conclude on proper identification and characterisation as required for a feed additive. The occurrence of potential toxic impurities could also not be assessed. Based on the new data provided, the feed additives hydroxypropyl methyl cellulose and methyl cellulose were properly identified and characterised and were shown to meet the specifications set for the food additives. Therefore, the conclusions of the safety assessments reached in the previous opinions for hydroxypropyl methyl cellulose and methyl cellulose meeting the food additive specifications, apply to the hydroxypropyl methyl cellulose and methyl cellulose under assessment as feed additives. The additives are considered safe for all animal species, the consumer and the environment. In the absence of data, the FEEDAP Panel is not in the position to conclude on the safety for the user.

Development of biopolymer coated calcium fortified rice using spraying and soaking methods

Transdermal drug delivery systems of indapamide have been formulated by using solvent casting method. Monolithic systems were prepared by using hydroxy propyl methyl cellulose (HPMC) and ethyl cellulose (EC) polymers by incorporating glycerine and dibutyl phthalate as plasticizers, respectively. All the patches were uniform with respect to physicochemical and scanning electron microscopy (SEM) evaluation. Th e in vitro drug release studies indicated that HPMC containing fi lms have shown better release than that of EC containing fi lms without any permeation enhancer. A total of eight monolithic systems were prepared by using a drug polymer ratio of 1:4 and incorporated diff erent vegetable oils as permeation enhancers in diff erent concentrations. Th e prepared systems released the drug in the following order: F3 > F4 > F7 > F5 > F8 > F6 > F1 > F2. Th e various permeation parameters such as fl ux, permeability coeffi cient, enhancement ratio and diff usion rate constants were determined for all the formulations. Th e maximum fl ux of 9.08 × 102 mg/ cm2 h was observed with HPMC monolithic system containing 30% w/w olive oil. A signifi cant improvement of fl ux was observed in the following order: olive oil > linseed oil > sunfl ower oil > cottonseed oil > coconut oil > castor oil. Further improvement of fl ux was observed, when 30% w/w olive oil was applied directly onto the skin prior to the studies. Th e in vitro release studies revealed that the release was sustained up to 24 h and it follows zero-order kinetics. All the fi lms were found to be stable at 37°C and 45°C with respect to their physical parameters and drug content. Key words: EC, HPMC, linseed oil, olive oil, permeation enhancers, sunfl ower oil, transdermal

Cellulose ether oleogels obtained by emulsion-templated approach without additional thickeners

Modulation of viscosity, microstructure and lipolysis of W/O emulsions by cellulose ethers during in vitro digestion in the dynamic and semi-dynamic gastrointestinal models

A collaborative study was performed to determine the reproducibility of a method for the determination of methylcellulose (MC) and hydroxypropyl methylcellulose (HPMC) in food. These widely used food gums possess unusual solubility characteristics and cannot accurately be determined by existing dietary fiber methods. The new method uses the enzyme-digestion procedure of AOAC Official Method 991.43. Digestate solutions must be refrigerated to fully hydrate MC or HPMC. The chilled solutions are filtered and analyzed by size-exclusion liquid chromatography. Collaborating laboratories received 28 samples containing MC or HPMC in the range of 0-100%. The sample set included blind duplicates of 5 food matrixes (bread, milk, fish, potato, and powdered juice drink). Cochran and Grubbs tests were used to eliminate outliers. For food samples containing MC, values for within-laboratory precision, repeatability relative standard deviation (RSDr), ranged from 4.2 to 16%, and values for among-laboratories precision, reproducibility relative standard deviation (RSDR), ranged from 11 to 20%. For HPMC samples, RSDr values ranged from 6.4 to 27%, and RSDR values ranged from 17 to 39%. Recoveries of MC and HPMC from the food matrixes ranged from 78 to 101%. These results show acceptable precision and reproducibility for the determination of MC and HPMC, for which no Official AOAC Methods exist. It is recommended that this method be adopted as AOAC Official First Action.