CLINICAL STUDIES ON THE FOLLOWING INGREDIENTS:
Highly purified and concentrated deep sea calamari Omega 3
Fish oil supplements in New Zealand are highly oxidized and do not meet label content of n-3 PUFA
We evaluated the quality and content of fish oil supplements in New Zealand. All encapsulated fish oil supplements marketed in New Zealand were eligible for inclusion. Fatty acid content was measured by gas chromatography. Peroxide values (PV) and anisidine values (AV) were measured, and total oxidation values (Totox) calculated. Only 3 of 32 fish oil supplements contained quantities of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that were equal or higher than labeled content, with most products tested (69%) containing <67%. The vast majority of supplements exceeded recommended levels of oxidation markers. 83% of products exceeded the recommended PV levels, 25% exceeded AV thresholds, and 50% exceeded recommended Totox levels. Only 8% met the international recommendations, not exceeding any of these indices. Almost all fish oil supplements available in the New Zealand market contain concentrations of EPA and DHA considerably lower than claimed by labels. Importantly, the majority of supplements tested exceeded the recommended indices of oxidative markers. Surprisingly, best-before date, cost, country of origin, and exclusivity were all poor markers of supplement quality.
Albert, Benjamin B., et al. “Fish oil supplements in New Zealand are highly oxidized and do not meet label content of n-3 PUFA.” Scientific reports 5 (2015): 7928.
Translocating southern rock lobsters (Jasusedwardsii) from deep-water to shallow inshore water enhances nutritional condition through omega-3 long-chain polyunsaturated fatty acid content
Deep-water southern rock lobsters (Jasusedwardsii) were translocated into shallow-water inshore reefs around Tasmania in an attempt to enhance their growth rates and market traits. We assessed changes in nutritional condition in adult, deep-water lobsters before and 12 months after relocation through variations in the lipid and fatty acid profiles in the hepatopancreas and muscle. Fatty acid compositions were similar between shallow and translocated lobsters and both were different from deep-water lobsters, suggesting a dietary difference between the deep and shallow-water lobsters, and a dietary change in deep-water lobsters after translocation. Nutritional condition indices, such as total lipid and triacylglycerol content, did not significantly vary between the lobster populations which may be due to within-population variability driven partly by differences in the molt stage of lobsters. Mean concentrations of fatty acids, lipid content and essential polyunsaturated fatty acids (PUFA) were higher in translocated lobsters than in both deep and shallow-water lobsters. Mean omega-3 long-chain PUFA content, in particular, eicosapentaenoic acid (EPA, 20:5n-3) increased by 30% in the muscle of translocated lobsters, resulting in an enhanced nutritional value and a change in overall body condition. This enhancement of key fatty acids, achieved through translocation, highlights the market potential of translocation for the commercial industry.
Chandrapavan, Arani, et al. “Translocating southern rock lobsters (Jasusedwardsii) from deep-water to shallow inshore water enhances nutritional condition through omega-3 long-chain polyunsaturated fatty acid content.” Journal of Experimental Marine Biology and Ecology 375.1-2 (2009): 9-15.
The technological approach of 1-O-alkyl-sn-glycerols separation from Berryteuthis magister squid liver oil
Biological active compounds, 1-O-alkyl-sn-glycerols (AG), were isolated from the liver oil of the squid Berryteuthis magister. The main components of the initial lipids were 1-O-alkyl-2,3-diacyl-sn-glycerols (38.50 %) and triacylglycerols (24.26 %). The first step of separation was the alkaline hydrolysis of oil to form a lipid mixture consisting of AG, free fatty acids and cholesterol. AG was separated by double recrystallization from acetone at −20 °C and 1 °C. A simple procedure is proposed for obtaining AG with a purity of 99.22 %, the main component of which is chimyl alcohol (94.39 %). Purity and structure of the obtained products were confirmed by GC and GC-MS technique. Isolated AG may be used in nutrition and cosmetics.
Ermolenko, Ekaterina, et al. “Technological approach of 1-O-alkyl-sn-glycerols separation from Berryteuthis magister squid liver oil.” Journal of food science and technology 53.3 (2016): 1722-1726.
A combined procedure of supercritical fluid extraction and molecular distillation for the purification of alkylglycerols from shark liver oil
Ethanolysis of squalene free shark liver oil was carried out to obtain a product mixture comprised mainly of fatty acid ethyl esters and non-esterified alkylglycerols. Purification of non-esterified alkylglycerols from this product mixture via supercritical fluid extraction and short-path distillation has been compared. The effect of temperature and mass flow in a sequential distillation strategy was evaluated. In addition, a combination of supercritical fluid extraction and short-path distillation to obtain a product highly enriched in alkylglycerols readily for human consumption was also studied.
Tenllado, Daniel, Guillermo Reglero, and Carlos F. Torres. “A combined procedure of supercritical fluid extraction and molecular distillation for the purification of alkylglycerols from shark liver oil.” Separation and purification technology 83 (2011): 74-81.
17 – Methods of concentration and purification of omega-3 fatty acids
An overview is presented of the various methodologies used for producing highly purified omega-3 fatty acids from natural source materials. Omega-3 fatty acids derived from fish, krill, and microalgae, consisting of eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3), have beneficial effects in the prevention and management of cardiovascular disease and other chronic disorders. Production of high-purity omega-3 fatty acids is increasingly important in both the nutraceutical and pharmaceutical industries. The physical, chemical and enzymatic methods used include urea adduction, chromatography, low-temperature fractional crystallization, supercritical fluid extraction, and distillation.
Senanayake, SPJ Namal. “Methods of concentration and purification of omega-3 fatty acids.” Separation, extraction and concentration processes in the food, beverage and nutraceutical industries. Woodhead Publishing, 2013. 483-505.
Flavored vegetarian cellulose capsule and methods for producing said capsule.
A flavored vegetable starch capsule and the method of manufacture of the flavored capsule is provided. The capsule may comprise (a) from about 95% to about 100% parts by weight of cellulose, such as hydroxymethylcellulose; (b) from about 0.5% to about 5.5% by weight of a suitable hydrogenated saccharide, such as sorbitol; (c) from about 0.2 to about 2.5% of a lubricant, such as silicon dioxide; (d) up to about 10% purified water; to which is added about 1/10 parts by weight of liquid flavoring.
Gilinski, Jonathan. “Flavored vegetarian cellulose capsule and methods for producing said capsule.” U.S. Patent Application No. 10/907,315.
The Role of Cellulose and O-Antigen Capsule in the Colonization of Plants by Salmonella enterica
Numerous salmonellosis outbreaks have been associated with vegetables, in particular, sprouted seed. Thin aggregative fimbriae (Tafi), a component of the extracellular matrix responsible for multicellular behavior, are important for Salmonella enterica attachment and colonization of plants. Here, we demonstrate that the other surface polymers composing the extracellular matrix, cellulose, and O-antigen capsule also play a role in the colonization of plants. Mutations in bacterial cellulose synthesis (bcsA) and O-antigen capsule assembly and translocation (yihO) reduced the ability to attach to and colonize alfalfa sprouts. A colanic acid mutant was unaffected in plant attachment or colonization. Tafi, cellulose synthesis, and O-antigen capsule, all of which contribute to attachment and colonization of plants, are regulated by AgfD, suggesting that AgfD is a key regulator for survival outside of hosts of Salmonella spp. The cellulose biosynthesis regulator adrA mutant was not affected in the ability to attach to or colonize plants; however, promoter probe assays revealed expression by cells attached to alfalfa sprouts. Furthermore, quantitative reverse-transcriptase polymerase chain reaction revealed differential expression of agfD and adrA between planktonic and plant-attached cells. In addition, there was no correlation among mutants between biofilm formation in culture and attachment to plants. Outside of animal hosts, S. enterica appears to rely on an arsenal of adhesins to persist on plants, which can act as vectors and perpetuate public health concerns.
Barak, Jeri D., et al. “The role of cellulose and O-antigen capsule in the colonization of plants by Salmonella enterica.” Molecular Plant-Microbe Interactions 20.9 (2007): 1083-1091.
A capsule shell comprising 79.6-98.7% by weight of a hydroxypropylmethyl cellulose, 0.03-0.5% by weight of carrageenan, and 0.14-3.19% by weight of a potassium ion and/or a calcium is prepared by drying an solution comprising 18-28% by weight of hydroxypropylmethyl cellulose whose 2% aqueous solution has a viscosity of 2.4-5.4 centistokes at 20° C. as a base, 0.01-0.09% by weight of carrageenan as a gelling agent, and 0.05-0.6% by weight of a potassium ion and/or calcium ion as a co-gelling agent. The capsule shell exhibits disintegrating ability equivalent to gelatin shells without degrading that ability even under special conditions containing much calcium ions.
Yamamoto, Taizo, Seinosuke Matsuura, and Kazukiyo Akai. “Capsule shell.” U.S. Patent No. 5,756,123. 26 May 1998.
Cellulose capsule using a mixed solution of pectin and glycerin and the manufacturing process thereof
The present invention provides a cellulose capsule comprising the steps of i) preparing a mixed solution of pectin and glycerin, ii) adding said mixed solution to solubilized cellulose aqueous solution, iii) adding a small amount of glacial acetic acid, calcium gluconate, sucrose fatty acid ester to said mixture, and iv) standing by adjusting viscosity and forming a capsule.
Yang, Joo Hwan. “Cellulose capsule using a mixed solution of pectin and glycerin and the manufacturing process thereof.” U.S. Patent No. 6,410,050. 25 Jun. 2002.
Cellulose and xylans in the interface capsule in symbiotic cells of actinorhizae
Enzyme-gold affinity labeling was used to show that in mature infected cells of actinorhizal symbioses the capsule on the plant host side of the symbiotic interface contained cellulose and xylans. Host species examined for cellulose wereAlnus rubra, Casuarina equisetifolia, C. glauca, Ceanothus cuneata, C. velutinus, Elaeagnus pungens, andMyrica cerifera.. Cellulose was in the capsule throughout the infected cell, implying that during development cellulose synthase was present in the host cell membrane component of the symbiotic interface. Any possible degradation of capsule cellulose by the microsymbiont was either incomplete or transient because the polymer was present in mature infected cells. Cellulose labeling inCeanothus andElaeagnus was less consistent than in the other species. Dual labeled capsules inCasuarina glauca and Alnus rubra showed a similar distribution of xylans and cellulose. Cytochemical studies indicate that the capsule contains three major classes of cell wall polysaccharides: cellulose, hemicellulose (xylans), and pectins (shown previously). This suggests that the capsule is essentially a thin, internal, tubular plant cell wall.
Berg, R. H. “Cellulose and xylans in the interface capsule in symbiotic cells of actinorhizae.” Protoplasma 159.1 (1990): 35-43.
Antioxidant Activity of Anthocyanin Extract from Purple Black Rice
Antioxidant activity was studied for anthocyanins extracted from purple-black rice (PBR) by a 3% aqueous trifluoroacetic acid solution (TFA), as well as for anthocyanins extracted from blueberry (Bluetta, high bush type). Capillary zone electrophoresis revealed that the PBR extract contained almost exclusively a single anthocyanin, which was identified as cyanidin 3-O-β-D-glucoside (Cy 3-Glc) after purification by polyvinylpyrrolidone column chromatography. In contrast, 11 anthocyanins were identified in the blueberry extract. PBR extract showed slightly weaker superoxide scavenging and crocin bleaching activities than blueberry extract did. Both PBR and blueberry extracts, however, showed 10 to 25 times stronger activity than the same concentration of Trolox used as a reference antioxidant. It was further noted that the purified Cy 3-Glc from PBR extract retained approximately 74% of the antioxidant activity (both crocin bleaching and superoxide scavenging) observed in the original TFA extract. The hydroxyl radical scavenging activity of both extracts was several times weaker than that of the same concentration of Trolox, although the PBR extract showed approximately two times stronger activity than blueberry extract did. The hydroxyl radical scavenging activity of the purified Cy 3-Glc from PBR, however, decreased to approximately 20% of that of the original PBR extract. These results indicate that the anthocyanin Cy 3-Glc contributes to the antioxidant activity of PBR through its strong superoxide radical but not hydroxyl radical scavenging activity.
Ichikawa, Haruyo, et al. “Antioxidant activity of anthocyanin extract from purple-black rice.” Journal of medicinal food 4.4 (2001): 211-218.
Red mold rice extract represses amyloid beta-peptide-induced neurotoxicity via potent synergism of anti-inflammatory and antioxidative effect
Amyloid β-peptide (Aβ), a risk of Alzheimer’s disease (AD), causes cell death by inflammation and oxidative stress. Red mold rice (RMR) fermented by Monascus species is regarded as a cholesterol-lowering functional food in virtue of the metabolite monacolin K identified as lovastatin. In addition, RMR is also demonstrated to express antioxidation because of multiple antioxidants. Therefore, this study focuses on the synergism of RMR against Aβ neurotoxicity and compares the effect between lovastatin and RMR including monacolin K and other functional metabolites. In this study, RE 568, an ethanol extract of RMR produced by strain Monascus purpureus NTU 568, is used to protect PC12 cell against Aβ40 neurotoxicity. All tests contain the treatments with lovastatin or RE 568 including equal monacolin K levels in order to compare the effect and investigate whether other metabolites of RE 568 provide potent assistance against Aβ40 neurotoxicity. In the results, monacolin K represses Aβ40 neurotoxicity via repressing small G-protein-mediated inflammation, and other metabolites of RE 568 also exhibit potent antioxidative ability against Aβ-induced oxidative stress. Importantly, stronger effects on repressing the Aβ40-induced cell death, inflammation, and oxidative stress are performed by RE 568 than that by the equal levels of lovastatin, which results from a potent synergism made up of monacolin K, antioxidants, and anti-inflammatory agents. The present study is the first report to demonstrate the potent synergistic protection of RMR against Aβ40 neurotoxicity, which would cause RMR to be developed as potential and novel functional food for the prophylaxis of AD pathogenesis.
Lee, Chun-Lin, Jyh-Jye Wang, and Tzu-Ming Pan. “Red mold rice extract represses amyloid beta-peptide-induced neurotoxicity via potent synergism of anti-inflammatory and antioxidative effect.” Applied microbiology and biotechnology 79.5 (2008): 829-841.
Iodine uptake in Laminariales involves extracellular, haloperoxidase-mediated oxidation of iodide
Sporophytes of Laminaria digitata (L.) Lamour. were assayed for their content of accumulated iodine, which ranged from 0.4% of dry weight in adult plants up to 4.7% for young plantlets. Sporophyte tissue from Laminaria saccharina (L.) Lamour. and L. digitata took up iodide according to Michaelis-Menten kinetics. Hydrogen peroxide and various substances are known to interfere with oxidative metabolism were shown to either inhibit or enhance the uptake of iodide, confirming that apoplastic oxidations play a key role in iodide uptake in Laminaria. Consistently, iodide uptake was triggered in L. saccharina protoplasts by incubation in the presence of hydrogen peroxide. Similarly, the uptake of iodide was enhanced in L. digitata gametophytes by addition of haloperoxidase, suggesting that this enzyme catalyzes the oxidation of iodide by hydrogen peroxide and plays a key role in iodine uptake. Oxidative stress resulted in a marked efflux of the intracellular iodine. In both influx and efflux experiments, a marked proportion (10–30%) of the tracer was not accounted for, indicating volatilization of iodine. The mechanism and possible functions of the accumulation of iodine by kelps are discussed.
Küpper, F. C., et al. “Iodine uptake in Laminariales involves extracellular, haloperoxidase-mediated oxidation of iodide.” Planta 207.2 (1998): 163-171.
A MULTI‐GENE MOLECULAR INVESTIGATION OF THE KELP (LAMINARIALES, PHAEOPHYCEAE) SUPPORTS SUBSTANTIAL TAXONOMIC RE‐ORGANIZATION†
Every year numerous ecological, biochemical, and physiological studies are performed using members of the order Laminariales. Despite the fact that kelp is some of the most intensely studied macroalgae in the world, there is significant debate over the classification within and among the three “derived” families, the Alariaceae, Laminariaceae, and Lessoniaceae (ALL). Molecular phylogenies published for the ALL families have generated hypotheses strongly at odds with the current morphological taxonomy; however, conflicting phylogenetic hypotheses and consistently low levels of support realized in all of these studies have resulted in conservative approaches to taxonomic revisions. In order to resolve relationships within this group we have sequenced over 6000 bp from regions in the nuclear, chloroplast, and mitochondrial genomes and included 42 taxa in Bayesian, neighbor‐joining, and parsimony analyses. The result is the first comprehensive and well‐supported molecular phylogeny for the ALL complex of the Laminariales. We maintain the three recognized families (Alariaceae, Laminariaceae, and Lessoniaceae), but with vastly different compositions, as well as propose the Costariaceae fam. nov. for Agarum, Costaria, Dictyoneurum, and Thalassiophyllum, the only general in the Laminariales with flattened, occasionally terete, stripes and either a perforated or reticulate blade. In addition, our data strongly support a split of the genus Laminaria. We resurrect the genus Saccharina Stackhouse for the Laminaria clade that does not contain L. digitata (Hudson) J.V. Lamouroux, the type of the genus.
Lane, Christopher E., et al. “A MULTI‐GENE MOLECULAR INVESTIGATION OF THE KELP (LAMINARIALES, PHAEOPHYCEAE) SUPPORTS SUBSTANTIAL TAXONOMIC RE‐ORGANIZATION 1.” Journal of Phycology 42.2 (2006): 493-512.
The Asian kelp Undaria pinnatifida (Phaeophyta: Laminariales) found in a New Zealand harbor
The kelp Undaria pinnatifida (Phaeophyta: Laminariales), native to Japan, Korea and parts of China, has been found growing subtidally to 7 m depth over a 4 km stretch of the shoreline of Wellington Harbour, New Zealand. In August 1987, some sporophytes were up to 1.3 m tall with fully developed sporophylls. Circumstantial evidence suggests Japanese and Korean fishing vessels may have carried Undaria to New Zealand within the last nine years. This is the second record of Undaria being inadvertently introduced to shores beyond Asia, and it is the first record of its occurrence in the Southern Hemisphere.
Hay, Cameron H., and Penelope A. Luckens. “The Asian kelp Undaria pinnatifida (Phaeophyta: Laminariales) found in a New Zealand harbor.” New Zealand Journal of Botany 25.2 (1987): 329-332.
A survey of translocation in Laminariales (Phaeophyceae)
A survey of translocation of photoassimilates in 13 genera of Laminariales is presented. All showed long-distance transport of 14C-labeled products from mature source tissue to meristematic sinks (haptera and intercalary growing regions). In plants with several laminae forming one frond, older laminae may provide assimilates for the growth of younger ones, and in Macrocystis spp., where fronds of different ages and developmental stage arise from a common holdfast, mature fronds initiate and support new fronds. Translocation velocities vary from species to species but are in the range of 55 to 570 mm/h. The results strongly support the hypothesis that Laminariales, in general, have an effective translocation system, on which their thallus growth depends.
Schmitz, K., and C. S. Lobban. “A survey of translocation in Laminariales (Phaeophyceae).” Marine Biology 36.3 (1976): 207-216.
The pattern of Laminariales distribution in the northeast Pacific
The distribution of 40 species of Laminariales is described for the northeast Pacific coast from Santa Margarita Island, Baja California, Mexico to Attu Island, Alaska, U. S. A., In general, this coast can be described as an area of gradual floristic change which can, however, be divided into seven broad transitional regions separated by regions of no floristic change. The relative distribution of Lessoniaceae, Alariaceae, and Laminariacea along the northeast Pacific coast defines three distinct coastal floras: a southern segment from Santa Margarita Island to the Strait of Juan de Fuca; a northern segment from Hope Island, British Columbia, Canada, to Yakutat, Alaska; and a western segment from Kodiak Island, Alaska to Attu Island, Alaska.
Druehl, Louis D. “The pattern of Laminariales distribution in the northeast Pacific.” Phycologia 9.3-4 (1970): 237-247.
Surface states at steam-grown silicon-silicon dioxide interfaces
A method of determining the energy distribution of surface states at silicon-silicon dioxide interfaces by using low-frequency differential capacitance measurements of MOS structures is described. Low-frequency measurements make it possible to determine the silicon surface potential as a function of MOS voltage directly from the experimental data without requiring knowledge of the Si doping profile. No graphical differentiations are required to determine the surface state density from the experimental curves, and errors introduced by uncertainties in the silicon doping density are reduced. Also, it is shown that the measurements can be used to determine the relative lateral uniformity in the characteristics of the oxide and interface under the MOS field plate. Nonuniformities can result in large errors in the surface-state density derived from MOS capacitance measurements. Measurements are presented and interpreted for both n- and p-type silicon samples prepared by bias-growing the oxide in steam.
Berglund, C. N. “Surface states at steam-grown silicon-silicon dioxide interfaces.” IEEE Transactions on Electron Devices 10 (1966): 701-705.
Diffusion of Metals in Silicon Dioxide
The diffusion coefficient and solubilities of several metals (Ag, Cu, Au, Pd, and Ti) have been investigated by bias temperature stress (BTS) of Formula (MOS) structures using the candidate metal as the electrode. Temperatures ranged from 250° to 600°C, and the electric fields ranged from +106 to −106 V/cm in ambients of vacuum (10−6 torr), nitrogen formula, and forming gas Formula. In dry Formula, the activation energy for silver diffusion is found to be 1.24 eV in the temperature range of 275°–365°C. The diffusion coefficient for silver at 300°C in silicon dioxide is Formula. Copper diffusion has an activation energy of 1.82 eV in the temperature range of 350°–450°C in a forming gas environmentFormula and a diffusion coefficient in Formula at 450°C of Formula. A thermodynamic model to predict the activation energy of the solid solubility of these metals in Formula and an interstitial diffusion model, that includes both strain and electrostatic energies, which predicts the diffusion activation energy, have been developed. Diffusion coefficients are estimated from a closed form solution of the diffusion equation and the observed behavior of the metal in Formula.
McBrayer, John David, R. M. Swanson, and T. W. Sigmon. “Diffusion of metals in silicon dioxide.” Journal of The Electrochemical Society 133.6 (1986): 1242-1246.
Optically active oxygen-deficiency-related centers in amorphous silicon dioxide
The spectroscopic properties, structure, and interconversions of optically active oxygen-deficiency-related point defects in vitreous silica are reviewed. These defects, the E′-centers (oxygen vacancies with a trapped hole or 3-fold-coordinated silicons), different variants of diamagnetic `ODCs’ (oxygen-deficiency centers), and their Ge-related analogs play a key role in the fiber-optic Bragg grating writing processes. The controversy surrounding the structural models for the Si- and Ge-related ODCs is discussed and the similarity between the bulk and surface point defects in silica is emphasized. The possible interconversion mechanisms between 2-fold-coordinated Si, neutral oxygen vacancies and E′-centers are discussed. The effects of the glassy disorder have a profound effect on defect properties and interconversion processes in silica.
Skuja, Linards. “Optically active oxygen-deficiency-related centers in amorphous silicon dioxide.” Journal of NON-crystalline Solids 239.1-3 (1998): 16-48.
Degradation of silicon dioxide films is shown to occur primarily near interfaces with contacting metals or semiconductors. This deterioration is shown to be accountable through two mechanisms triggered by electron heating in the oxide conduction band. These mechanisms are trap creation and band‐gap ionization by carriers with energies exceeding 2 and 9 eV with respect to the bottom of the oxide conduction band, respectively. The relationship of band‐gap ionization to defect production and subsequent degradation is emphasized. The dependence of the generated sites on the electric field, oxide thickness, temperature, voltage polarity, and processing for each mechanism is discussed. A procedure for separating and studying these two generation modes is also discussed. A unified model from simple kinetic relationships is developed and compared to the experimental results. Destructive breakdown of the oxide is shown to be correlated with ‘‘effective” interface softening due to the total defect generation caused by both mechanisms.
DiMaria, D. J., E. Cartier, and D. Arnold. “Impact ionization, trap creation, degradation, and breakdown in silicon dioxide films on silicon.” Journal of Applied Physics 73.7 (1993): 3367-3384.
Ellipsometric determination of optical constants for silicon and thermally grown silicon dioxide via a multi-sample, multi-wavelength, multi-angle investigation
Optical constant spectra for silicon and thermally grown silicon dioxide have been simultaneously determined using a variable angle of incidence spectroscopic ellipsometry from 0.75 to 6.5 eV. Spectroscopic ellipsometric data sets acquired at multiple angles of incidence from seven samples with oxide thicknesses from 2 to 350 nm were analyzed using a self-contained multi-sample technique to obtain Kramers–Kronig consistent optical constant spectra. The investigation used a systematic approach utilizing optical models of increasing complexity in order to investigate the need for fitting the thermal SiO2 optical constants and including an interface layer between the silicon and SiO2 in modeling the data. A detailed study was made of parameter correlation effects involving the optical constants used for the interface layer. The resulting thermal silicon dioxide optical constants were shown to be independent of the precise substrate model used and were found to be approximately 0.4% higher in the index than published values for bulk glasses SiO2. The resulting silicon optical constants are comparable to previous ellipsometric measurements in the regions of overlap and are in agreement with long wavelength prism measurements and transmission measurements near the band gap.
Herzinger, C. M., et al. “Ellipsometric determination of optical constants for silicon and thermally grown silicon dioxide via a multi-sample, multi-wavelength, multi-angle investigation.” Journal of Applied Physics 83.6 (1998): 3323-3336.
Bonding characteristics by scanning electron microscopy of powders mixed with magnesium stearate
The effect of degree of mixing on the bonding properties of blends of magnesium stearate and tablet excipients is shown to be dependent upon the compression behavior and bonding mechanism of the excipient studied. Magnesium stearate exercises a maximum effect on excipients such as the starch derivative Amylose V, which undergoes complete plastic deformation without any fragmentation and is bonded by cohesion. The effect on excipients bonded by cold-bonding mechanisms after a plastic flow of the crystals, as demonstrated for sodium chloride, is dependent on the extent to which clean, lubricant-free surfaces are formed during compression. The bonding properties of excipients such as dicalcium phosphate dihydrate, which undergo complete fragmentation under pressure, are practically uninfluenced by mixing with magnesium stearate.
De Boer, A. H., G. K. Bolhuis, and C. F. Lerk. “Bonding characteristics by scanning electron microscopy of powders mixed with magnesium stearate.” Powder Technology 20.1 (1978): 75-82.
Interaction of tablet disintegrants and magnesium stearate during mixing I: Effect on tablet disintegration
The effect of magnesium stearate on the disintegration of tablets was studied. Three different blends, containing a slightly or a strongly swelling disintegrant, were mixed before compression with magnesium stearate for different time periods. The results show that a strongly swelling disintegrant, such as sodium starch glycolate in contrast to potato starch, can reduce the deteriorating effect of hydrophobic lubricants on tablet disintegration. However, the interaction between magnesium stearate and potato starch or sodium starch glycolate and the resulting differences in disintegration characteristics can be masked by the use of disks in the USP disintegration apparatus.
Bolhuis, G. K., A. J. Smallenbroek, and C. F. Lerk. “Interaction of tablet disintegrants and magnesium stearate during mixing I: Effect on tablet disintegration.” Journal of pharmaceutical sciences 70.12 (1981): 1328-1330.
Effect of magnesium stearate on bonding and porosity expansion of tablets produced from materials with different consolidation properties
The negative effect of magnesium stearate on tablet strength is widely known. This strength reduction is always considered to be the result of a reduction of interparticle bonding. It is also known that interparticle bonding affects the relaxation of tablets. Relaxation increases with decreasing bonding. Microcrystalline cellulose is an example of a material with a high lubricant sensitivity, which effect is caused by its plastic deformation behavior during compression. This paper shows for microcrystalline cellulose that the porosity under pressure was equal for unlubricated tablets and for tablets containing 0.5% magnesium stearate. This points to equal densification properties. The lubricated tablets show, however, a much larger relaxation than the tablets without magnesium stearate. This difference can be ascribed to the reduction of interparticle bonding by the lubricant because a strong interparticle bonding counteracts tablet relaxation. In contrast to microcrystalline cellulose, aggregated γ-sorbitol (Karion Instant) has a low lubricant sensitivity. Both porosities under pressure and tablet relaxation were found to be equal for lubricated and unlubricated sorbitol tablets. This phenomenon is caused by the particle structure of γ-sorbitol. During compression, a lubricant film will be destroyed by fragmentation of the sorbitol aggregates. For this reason, magnesium stearate will hardly affect the interparticle bonding between sorbitol particles and hence have only a small or no effect on tablet relaxation.
Zuurman, K., K. Van der Voort Maarschalk, and G. K. Bolhuis. “Effect of magnesium stearate on bonding and porosity expansion of tablets produced from materials with different consolidation properties.” International Journal of Pharmaceutics 179.1 (1999): 107-115.
Chemical, Physical, and Lubricant Properties of Magnesium Stearate
Three batches of commercial magnesium stearate were characterized in terms of their fatty acid composition, moisture content, and specific surface area. None of these variables appeared to have any effect on the lubricant activity of the samples. The lubricant properties of the compound were further examined using three hydrates of laboratory‐prepared (pure) magnesium stearate. Based on the results obtained from the pure samples, it appears that differences in the lubricant properties of magnesium stearate are correlated with differences in moisture content and crystalline structure.
Ertel, K. D., and J. T. Carstensen. “Chemical, physical, and lubricant properties of magnesium stearate.” Journal of pharmaceutical sciences 77.7 (1988): 625-629.
Densification properties and compatibility of mixtures of pharmaceutical excipients with and without magnesium stearate
Mixtures of a plastically deforming substance and a brittle one often lead to a positive interaction in the compatibility. It was observed that a deviation in the tablet strength from the linear interpolated value is often related to a similar deviation in tablet thickness. The densification properties of both the brittle and the plastic materials appeared to be of importance in this respect. Blends of different directly compressible filler binders with magnesium stearate resulted most often in negative interactions incompatibility. In some cases, however, a positive interaction was found. From the results, it is speculated that the influence of magnesium stearate (used as a lubricant) on the binding properties of directly compressible materials is directly related to the densification behavior of the filler-binder. The negative effect of the lubricant on the binding properties is thought to be counteracted by the facilitated densification.
Vromans, H., and C. F. Lerk. “Densification properties and compatibility of mixtures of pharmaceutical excipients with and without magnesium stearate.” International Journal of Pharmaceutics 46.3 (1988): 183-192.