Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Silicates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2003

Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.

This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers <5 microm were not classified as to their carcinogenicity to humans. Likewise, Clinoptilolite, Phillipsite, Mordenite, Nonfibrous Japanese Zeolite, and synthetic Zeolites were not classified as to their carcinogenicity to humans. These ingredients are not significantly toxic in oral acute or short-term oral or parenteral toxicity studies in animals. Inhalation toxicity, however, is readily demonstrated in animals. Particle size, fibrogenicity, concentration, and mineral composition had the greatest effect on toxicity. Larger particle size and longer and wider fibers cause more adverse effects. Magnesium Aluminum Silicate was a weak primary skin irritant in rabbits and had no cumulative skin irritation in guinea pigs. No gross effects were reported in any of these studies. Sodium Magnesium Silicate had no primary skin irritation in rabbits and had no cumulative skin irritation in guinea pigs. Hectorite was nonirritating to the skin of rabbits in a Draize primary skin irritation study. Magnesium Aluminum Silicate and Sodium Magnesium Silicate caused minimal eye irritation in a Draize eye irritation test. Bentonite caused severe iritis after injection into the anterior chamber of the eyes of rabbits and when injected intralamellarly, widespread corneal infiltrates and retrocorneal membranes were recorded. In a primary eye irritation study in rabbits, Hectorite was moderately irritating without washing and practically nonirritating to the eye with a washout. Rats tolerated a single dose of Zeolite A without any adverse reaction in the eye. Calcium Silicate had no discernible effect on nidation or on maternal or fetal survival in rabbits. Magnesium Aluminum Silicate had neither a teratogenic nor adverse effects on the mouse fetus. Female rats receiving a 20% Kaolin diet exhibited maternal anemia but no significant reduction in birth weight of the pups was recorded. Type A Zeolite produced no adverse effects on the dam, embryo, or fetus in either rats or rabbits at any dose level. Clinoptilolite had no effect on female rat reproductive performance. These ingredients were not genotoxic in the Ames bacterial test system. In primary hepatocyte cultures, the addition of Attapulgite had no significant unscheduled DNA synthesis. Attapulgite did cause significant increases in unscheduled DNA synthesis in rat pleural mesothelial cells, but no significant increase in sister chromosome exchanges were seen. Zeolite particles (<10 microm) produced statistically significant increase in the percentage of aberrant metaphases in human peripheral blood lymphocytes and cells collected by peritoneal lavage from exposed mice. Topical application of Magnesium Aluminum Silicate to human skin daily for 1 week produced no adverse effects. Occupational exposure to mineral dusts has been studied extensively. Fibrosis and pneumoconiosis have been documented in workers involved in the mining and processing of Aluminum Silicate, Calcium Silicate, Zirconium Silicate, Fuller's Earth, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite. The Cosmetic Ingredient Review (CIR. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that the extensive pulmonary damage in humans was the result of direct occupational inhalation of the dusts and noted that lesions seen in animals were affected by particle size, fiber length, and concentration. The Panel considers that most of the formulations are not respirable and of the preparations that are respirable, the concentration of the ingredient is very low. Even so, the Panel considered that any spray containing these solids should be formulated to minimize their inhalation. With this admonition to the cosmetics industry, the CIR Expert Panel concluded that these ingredients are safe as currently used in cosmetic formulations. The Panel did note that the cosmetic ingredient, Talc, is a hydrated magnesium silicate. Because it has a unique crystalline structure that differs from ingredients addressed in this safety assessment, Talc is not included in this report.

Animals↗
PubMed2006

Micellization of CTAB in the presence of silicate anions and the exchange between bromide and silicate at the micelle surface: A step to understand the formation of mesoporous molecular sieves at extremely low surfactant and silicate concentrations.

The effect of silicate anions, from dilute aqueous tetramethylammonium silicate (TMASi) solutions (0-3.0 mmol L(-1) in silicon), on the formation of hexadecyltrimethylammonium bromide (CTAB) micelles was investigated by means of a series of simple conductivity experiments. These two compounds are used in the preparation of mesoporous silicate molecular sieves. An increase in the monovalent silicate anion concentration decreases the critical micelle concentration (cmc) of CTAB, as might be expected from the decreased repulsive forces between the polar heads of the surfactant molecules. However, the decrease in cmc values is less pronounced than that observed in the presence of bromide ions, suggesting that Br- binds more strongly than Si(OH)3O- at the micelle surface. Through the ion-exchange formalism, a selectivity coefficient for Si(OH)3O-/Br- exchange of 0.30+/-0.03 was estimated from the conductivity data. This value compares well with that of 0.4+/-0.1 also determined in this work by the pyrene fluorescence quenching method. The experimental results were used to rationalize the formation of a surfactant supramolecular-templated mesoporous molecular sieve at extremely low surfactant (0.63 mmol L(-1)) and silicate (4.00 mmol L(-1)) concentrations.

Journal Article↗
PubMed2002

Simulated annealing structure solution of a new phase of dicalcium silicate Ca(2)SiO(4) and the mechanism of structural changes from alpha-dicalcium silicate hydrate to alpha(L)'-dicalcium silicate via the new phase.

A new phase of dicalcium silicate (Ca(2)SiO(4)) was formed by heating alpha-dicalcium silicate hydrate [alpha-Ca(2)(SiO(4)H)OH = alpha-C(2)SH] at temperatures of approximately 663-763 K, and it was transformed into alpha(L)'-Ca(2)SiO(4) (= alpha(L)'-C(2)S) above approximately 1193 K. The crystal structure of the new phase (hereafter called x-C(2)S) has been determined by simulated annealing and refined by the Rietveld method using synchrotron radiation powder diffraction data. The structure consists of isolated SiO(4) tetrahedra and a three-dimensional CaO(n) polyhedral network, forming a new structural type of dicalcium silicate. A structural change from alpha-C(2)SH to x-C(2)S is compelled by large displacements of SiO(4) tetrahedra, accompanied by dehydration, in the direction perpendicular to the two-dimensional Ca(O,OH)(n) polyhedral network in alpha-C(2)SH. With increasing temperature, sizes of CaO(n) polyhedra in x-C(2)S become too large to confine Ca atoms at the sixfold to eightfold coordination sites. Then the structure of x-C(2)S is transformed into alpha(L)'-C(2)S, having eightfold to tenfold coordination sites for the Ca atoms.

Journal Article↗
PubMed2002

The hexacoordinate silicate dianions mer-tris[glycolato(2-)-O(1),O(2)]silicate and fac-tris[benzilato(2-)-O(1),O(2)]silicate: syntheses and structural characterization.

Treatment of tetramethoxysilane with glycolic acid and morpholine (molar ratio 1:3:2) in methanol, followed by crystallization from methanol/tetrahydrofuran, yielded morpholinium mer-tris[glycolato(2-)-O(1),O(2)]silicate (mer-7). Treatment of benzilic acid with sodium hydride, followed by addition of tetrachlorosilane and triethylamine (molar ratio 3:4:1:2), afforded, after crystallization from 1,4-dioxane/acetonitrile/diethyl ether/n-pentane, triethylammonium fac-tris[benzilato(2-)-O(1),O(2)]silicate-hemi-1,4-dioxane (fac-8.(1)/(2)C(4)H(8)O(2)). Single-crystal X-ray diffraction studies showed that the Si-coordination polyhedra of the hexacoordinate silicon(IV) complexes mer-7 and fac-8.(1)/(2)C(4)H(8)O(2) are distorted octahedra. Both compounds were additionally characterized by solid-state VACP/MAS NMR studies ((13)C, (29)Si), and fac-8.(1)/(2)C(4)H(8)O(2) was studied in solution by (1)H, (13)C, and (29)Si NMR experiments. The structural investigations were complemented by computational studies (MP2 studies, TZP level) of the dianions of fac-7 and mer-7.

Journal Article↗
PubMed2005

Final report on the safety assessment of potassium silicate, sodium metasilicate, and sodium silicate.

Potassium Silicate, Sodium Metasilicate, and Sodium Silicate combine metal cations with silica to form inorganic salts used as corrosion inhibitors in cosmetics. Sodium Metasilicate also functions as a chelating agent and Sodium Silicate as a buffering and pH adjuster. Sodium Metasilicate is currently used in 168 formulations at concentrations ranging from 13% to 18%. Sodium Silicate is currently used in 24 formulations at concentrations ranging from 0.3% to 55%. Potassium Silicate and Sodium Silicate have been reported as being used in industrial cleaners and detergents. Sodium Metasilicate is a GRAS (generally regarded as safe) food ingredient. Aqueous solutions of Sodium Silicate species are a part of a chemical continuum of silicates based on an equilibrium of alkali, water, and silica. pH determines the solubility of silica and, together with concentration, determines the degree of polymerization. Sodium Silicate administered orally is readily absorbed from the alimentary canal and excreted in the urine. The toxicity of these silicates has been related to the molar ratio of SiO2/Na2O and the concentration being used. The Sodium Metasilicate acute oral LD50 ranged from 847 mg/kg in male rats to 1349.3 mg/kg in female rats and from 770 mg/kg in female mice to 820 mg/kg in male mice. Gross lesions of variable severity were found in the oral cavity, pharynx, esophagus, stomach, larynx, lungs, and kidneys of dogs receiving 0.25 g/kg or more of a commercial detergent containing Sodium Metasilicate; similar lesions were also seen in pigs administered the same detergent and dose. Male rats orally administered 464 mg/kg of a 20% solution containing either 2.0 or 2.4 to 1.0 ratio of sodium oxide showed no signs of toxicity, whereas doses of 1000 and 2150 mg/kg produced gasping, dypsnea, and acute depression. Dogs fed 2.4 g/kg/day of Sodium Silicate for 4 weeks had gross renal lesions but no impairment of renal function. Dermal irritation of Potassium Silicate, Sodium Metasilicate, and Sodium Silicate ranged from negligible to severe, depending on the species tested and the molar ratio and concentration tested. Sodium Metasilicate was negative in the local lymph node assay (LLNA), but a delayed-type hypersensitivity response was observed in mice. Potassium Silicate was nonirritating in two acute eye irritation studies in rabbits. Sodium Metasilicate (42.4% H2O) was corrosive to the rabbit eye. Sodium Silicate was a severe eye irritant in some eye irritation studies, but was irritating or nonirritating in others. A skin freshener containing Sodium Silicate was nonirritating. Sodium Metasilicate was nonmutagenic in bacterial cells. Rats given Sodium Silicate (600 and 1200 ppm of added silica) in the drinking water in reproductive studies produced a reduced number of offspring: to 67% of controls at 600 ppm and to 80% of controls at 1200 ppm. Three adult rats injected intratesticularly and subcutaneously with 0.8 mM/kg of Sodium Silicate showed no morphological changes in the testes and no effect on the residual spermatozoa in the ductus deferens. Sodium Metasilicate (37% in a detergent) mixed with water was a severe skin irritant when tested on intact and abraded human skin, but 6%, 7%, and 13% Sodium Silicate were negligible skin irritants to intact and abraded human skin. Sodium Silicate (10% of a 40% aqueous solution) was negative in a repeat-insult predictive patch test in humans. The same aqueous solution of Sodium Silicate was considered a mild irritant under normal use conditions in a study of cumulative irritant properties. The Cosmetic Ingredient Review (CIR) Expert Panel recognized the irritation potential of these ingredients, especially in leave-on products. However, because these ingredients have limited dermal absorption and Sodium Metasilicate is a GRAS direct food substance, the Panel deemed the ingredients safe for use in cosmetic products in the practices of use and concentration described in this safety assessment, when formulated to avoid irritation.

Animals↗
PubMed1987

Interrelationship between hemolysis and lipid peroxidation of human erythrocytes induced by silicic acid and silicate dusts.

Silicic acid and silicate dusts (slate dust and chrysotile asbestos) cause hemolysis of erythrocytes in vitro. The peroxidation of polyunsaturated fatty acids (PUFA) of erythrocyte membrane lipids is also enhanced by incubating the erythrocytes with silicic acid and silicate dusts in in vitro. Hemolysis of erythrocytes elicited by silicic acid and silicate dusts is inhibited significantly by polyvinyl-pyrrolidone and dipalmitoyl lecithin (DPL). These agents, however, have no effect on silicic acid and silicate dust induced peroxidation of erythrocyte membrane lipids. On the other hand, peroxidation of erythrocyte membrane lipids, induced by silicic acid and silicate dusts, is inhibited almost completely by adding superoxide dismutase and catalase to the incubation system, whilst the hemolysis of erythrocytes induced by silicic acid and silicate dusts is unaffected by these agents. Similarly the lysis of erythrocytes, induced by silicic acid and silicate dusts, proceeds at a much faster rate than silicic acid and silicate dust induced lipid peroxidation. These results indicate that silicic acid and silicate dust induced hemolysis and lipid peroxidation represent two independent processes.

Asbestos↗
PubMed1995

Influences of silicates and carnitine-silicate mixtures on the inhibition of aggregation of erythrocytes elicited by the presence of fibrinogen.

Carnitine and acylcarnitine derivatives have been reported to inhibit cell aggregation (Fritz and Burdzy, 1989, J. Cell. Physiol., 140:18-28). A follow-up of these observations showed that whereas the previously described effects of long-chain acylcarnitines were well replicated, those of carnitine on erythrocytes showed marked variability. The latter phenomenon was traced to the presence of silicates in carnitine solutions derived from the use of sodium hydroxide solutions stored in glass containers for the neutralization of carnitine. The present experiments have led to the discovery that oligomeric forms of silicates are powerful inhibitors of red blood cell aggregation which otherwise occurs in the presence of fibrinogen alone. The active form(s) of silicates in this assay, which appear to be generated by polymerization of silicates in metasilicate solutions on neutralization, are unstable and therefore transient under usual conditions. We estimate that the active oligomeric forms contain between 4 to 18 silicon atoms per molecule. When maintained at -18 degrees C in the presence of carnitine, but not in its absence, the active forms of oligomeric silicates remained stable for months, judging from their ability to inhibit cell aggregation. We conclude that carnitine stabilized the oligomeric form(s) of silicate, or that the species stabilized is an oligomeric silicate-carnitine complex. Comparable concentrations of choline, deoxycarnitine, or gamma-aminobutyrate were less effective in stabilizing the active silicate oligomers. The active forms of the silicate oligomers had Ki values of about 10 microM, calculated as the monomeric form, in inhibiting red blood cell aggregation. The data indicate that free carnitine does not directly inhibit erythrocyte inhibition, as previously interpreted, whereas long-chain acylcarnitine derivatives are active in the absence of silicates. Possible mechanism of actions of silicate oligomers on membranes are discussed.

Carnitine↗
PubMed2006

Molecular aggregation of rhodamine dyes in dispersions of layered silicates: influence of dye molecular structure and silicate properties.

The molecular aggregation of six rhodamine dyes (rhodamine 560, B, 3B, 19, 6G, 123) in layered silicate (saponite and fluorohectorite) dispersions was investigated by using visible (vis) spectroscopy. The dye molecular aggregation was influenced by the properties of both the silicates and the dyes themselves. The layer charge of the silicates enhanced the molecular aggregation of the hydrophilic, cationic dyes. The presence of a carboxyl acid group in the dye molecules inhibited adsorption of the dyes on the surface of fluorohectorite, a silicate with a high charge density. A lower or no adsorption could be observed by vis spectroscopy. Strong association of the dyes to the silicate surface led to remarkable changes in the dye spectra, mainly due to the molecular aggregation. Dye assemblies initially formed after mixing the dye solutions with silicate dispersions were unstable. Decomposition of the dye molecular assemblies, and the formation of new species or molecular aggregate rearrangements, were studied on the bases of time-difference spectra. The reaction pathways were specific, not only for the dyes, depending upon their molecular structure and properties, but also on the silicate substrates.

Journal Article↗
PubMed2002

A study of the alumina-silica gel adsorbent for the removal of silicic acid from geothermal water: increase in adsorption capacity of the adsorbent due to formation of amorphous aluminosilicate by adsorption of silicic acid.

Two kinds of adsorbents (Si adsorbent and Al adsorbent) for the removal of silicic acid from geothermal water to retard the formation of silica scales were prepared using silicic acid contained in geothermal water. The Si adsorbent was prepared by evaporating geothermal water, and the Al adsorbent was prepared by evaporating geothermal water after the addition of aluminum chloride. The specific surface area of the Si adsorbent was small and it's adsorption capacity of silicic acid was low. Although the specific surface area of the Al adsorbent was also small, it was significantly increased by the adsorption of silicic acid and it's adsorption capacity was high. Based on the change in the local structure of aluminum ion by the adsorption of silicic acid, the Al adsorbent was considered to be silica particles covered with crystalline aluminum hydroxide. Moreover, it was concluded that the increase in the specific surface area of the Al adsorbent and the decrease in the zeta potential were due to the formation of an amorphous aluminosilicate with a large surface area and a negative charge (one 4-coordinated Al) by the reaction between aluminum ions and silicic acids.

Adsorption↗
PubMed1983

Binding of silicic acid by proteins and its relation to toxicity of silicate dusts.

A possible mechanism of biological effects of silicate dusts is the interaction between silicic acid and tissue constituents, and this has been studied in vitro. On incubating silicic acid with lung homogenate, appreciable amounts of silicon were recovered in the trichloroacetic acid precipitate in both organic solvent extract and residual protein. Polyvinyl pyrrolidone inhibited this interaction as well as reducing the dissolution of silicic acid from asbestos dust. The capacity of serum albumin to bind silicic acid was also observed. Chemical interaction between macromolecules and silicic acid could be one of the factors responsible for the biological effects of silicon-containing dusts.

Animals↗
PubMed2001

Novel silicate anion: Si(8)O(22)(12-). Hydrothermal synthesis and X-ray powder structure of three new niobium silicates.

A sodium niobium(V) tetrasilicate, Na(2)H(NbO)Si(4)O(11).1.25H(2)O (1), was synthesized hydrothermally at 190 degrees C from a mixture of silicic acid, NaOH, NbCl(5), and H(2)O(2) and added hydrochloric acid. The successive treatment of 1 with nitric acid yielded HNb(H(2)O)Si(4)O(11).H(2)O (2). Contact of 2 with cesium hydroxide solutions converted it to the partially exchanged Cs(+) phase Cs(0.66)H(0.33)Nb(H(2)O)Si(4)O(11) (3). The three structures were solved from X-ray powder diffraction data. All compounds crystallize in the monoclinic space group P2(1)/m with Z = 2, containing the Si(8)O(22)(12-) anion. This new silicate anion type is related to the Si(4)O(11)(6-) unit, which is present in the amphibole series. The difference between both anion types lies in the chain periodicity: two for amphiboles or four for the new niobium silicates. These niobium silicates have framework structures enclosing tunnels in which the alkali cations reside.

Journal Article↗
PubMed2005

K5(UO2)2[Si4O12(OH)]: a uranyl silicate containing chains of four silicate tetrahedra linked by SiO...HOSi hydrogen bonds.

A new uranium(VI) silicate, K5(UO2)2[Si4O12(OH)], has been synthesized by a high-temperature, high-pressure hydrothermal method. It crystallizes in the orthorhombic space group Pbcm (No. 57) with a = 13.1274(7) A, b = 12.2635(7) A, c = 22.233(1) A, and Z= 8. Its structure consists of unbranched chains of four silicate tetrahedra extending along the b axis linked together via corner-sharing by UO6 tetragonal bipyramids to form a 3-D framework, which delimits intersecting channels along the c and b axes to accommodate K+ cations. A hydrogen atom is bonded to a terminal oxygen of a terminal silicate in the oligosilicate anion. Adjacent chains are linked along the b axis by hydrogen bonds. The sample shows a resonance at 14.7 ppm the 1H MAS NMR spectrum, which is assigned to the SiO...HOSi hydrogen bond. A comparison of uranyl silicate structures is made.

Journal Article↗
PubMed1988

Diseases associated with exposure to silica and nonfibrous silicate minerals. Silicosis and Silicate Disease Committee.

Silicosis, a disease of historical importance, continues to occur cryptically today. Its pathogenesis is under ongoing study as new concepts of pathobiology evolve. In this article, the gross and microscopic features of the disease in the lungs and the lesions in lymph nodes and other viscera are described. These tissue changes are then discussed in the context of clinical disease and other possible or established complications of silica exposure (ie, scleroderma and rheumatoid arthritis, glomerulonephritis, and bronchogenic carcinoma). Silicates are members of a large family of common minerals, some of which have commercial importance. Silicates are less fibrogenic than silica when inhaled into the lungs, but cause characteristic lesions after heavy prolonged exposure. The features of these disease conditions are described herein. Various aspects of the mineralogy and tissue diagnosis of silicosis and lung disease due to silicates are reviewed. An overview of contemporary regulatory considerations is provided.

Aluminum Silicates↗
PubMed2006

Rb6(InCo)2(Si9O26): a mixed-metal silicate containing 20-membered-ring silicate single layers with a very low Si:O ratio.

A new cobalt-indium silicate, Rb6(InCo)2(Si9O26), has been synthesized via a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction. It crystallizes in the noncentrosymmetric orthorhombic space group Aba2 (No. 41) with a = 20.779(1) A, b = 12.0944(6) A, c = 10.7761(5) A, V =2708.1(2) A(3), and Z = 4. The structure consists of 20-membered-ring silicate single layers of corner-sharing SiO4 tetrahedra interconnected by dimers of edge-sharing CoO4 tetrahedra and InO6 octahedra into a 3D framework. The Si:O ratio for the title compound is the lowest among the known single-layer silicates. Magnetic susceptibility confirms the divalent state of the cobalt ion. The powder sample has a second-harmonic-generation signal, confirming the absence of a center of symmetry in the structure.

Journal Article↗
PubMed2006

Monitoring temporal evolution of silicate species during hydrolysis and condensation of silicates using mass spectrometry.

The first stages of solid-state formation from solution can be crucial in determining the properties of the resulting solids. We are trying to approach prenucleation reactions of silicates from an aqueous solution containing tetraalkylammoniumhydroxides (TAAOH) and tetraalkoxysilanes (TAOS) by analyzing hydrolysis and condensation using electrospray mass spectrometry (ESI MS). Time-resolved measurements were performed using different reactor systems to show the stepwise hydrolysis of the silanes and subsequent condensation of silicate monomers via oligomers to form larger units. We approached the precipitation point by varying the pH and the concentrations of the reactants. The results show the evolution of different silicate species occurring during condensation. No defined molecular entities were identified at pH values close to precipitation, which suggests that under the conditions used, solids are probably not formed from defined building blocks.

Journal Article↗
PubMed1994

Application of calcium silicate for medicinal preparation. I. Solid preparation adsorbing an oily medicine to calcium silicate.

Calcium silicate (Florite RE, FLR), a fine porous powder, was recently approved as a medicinal additive. In this study we sought to make a solid preparation by absorbing an oily medicine to FLR; tocopheryl nicotinate (TN) was used as the oily medicine. TN adsorbed to FLR powder (TN-PO) was prepared by adsorbing TN ethanol solution to FLR and granulating with hydroxypropylcellulose (HPC) in order to improve the flowability. The results were as follows. FLR showed an excellent liquid holding ability compared with other excipients, and this was attributed to the high capillarity of the pores. In the adsorbing process, FLR particles were granulated with TN overflowing from the pores or adhering to the particle surface. The angle of repose was decreased with increasing TN content, which was attributed to the process of granulation, and the angle of repose of the granules with a binder (TN-GR) was below 40 degrees at any TN content. These results show that FLR is an useful additive for the solid preparation of an oily medicine.

Adsorption↗