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CAS no.: 557-04-0
EC / List no.: 209-150-3
Magnesium stearate is the chemical compound with the formula Mg(C18H35O2)
Magnesium stearate is a soap, consisting of salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+).
Magnesium stearate is a white, water-insoluble powder.
Magnesium stearates applications exploit its softness, insolubility in many solvents, and low toxicity.
Magnesium stearate is used as a release agent and as a component or lubricant in the production of pharmaceuticals and cosmetics
Magnesium stearate is produced by the reaction of sodium stearate with magnesium salts or by treating magnesium oxide with stearic acid.
Some nutritional supplements specify that the sodium stearate used in manufacturing magnesium stearate is produced from vegetable-derived stearic acid.
Magnesium stearate is often used as an anti-adherent in the manufacture of medical tablets, capsules and powders.
In this regard, the substance is also useful because Magnesium stearate has lubricating properties, preventing ingredients from sticking to manufacturing equipment during the compression of chemical powders into solid tablets; magnesium stearate is the most commonly used lubricant for tablets.
However, it might cause lower wettability and slower disintegration of the tablets and slower and even lower dissolution of the drug.
Magnesium stearate can also be used efficiently in dry coating processes.
In the creation of pressed candies, magnesium stearate acts as a release agent and Magnesium stearate is used to bind sugar in hard candies such as mints.
Magnesium stearate is a common ingredient in baby formulas
Magnesium stearate is a major component of bathtub rings.
When produced by soap and hard water, magnesium stearate and calcium stearate both form a white solid insoluble in water, and are collectively known as soap scum.
Magnesium stearate is a salt that forms when stearate molecules bond with a magnesium ion.
Stearate comes from stearic acid, a long-chain saturated fat found in:
Beef
Chicken
Cocoa butter
Coconut oil
Eggs
Milk and dairy products
Palm oil
Salmon
Experts say stearic acid is the only long-chain saturated fat that does not raise cholesterol levels.
In the form of a powder, the salt forms the coating that you see on medications and vitamins.
Magnesium stearate may stick to your hands and feel greasy when you touch it.
Makers of many processed foods, cosmetics, and pharmaceuticals also add magnesium stearate to their products.
Medications.
Companies call magnesium stearate a “flow agent.”
magnesium stearates main job is to keep the ingredients in a capsule from sticking together.
magnesium stearate also forms a barrier between the medicines and the machines that make them.
The powder improves the consistency and quality of the medication capsules.
Another function of the powder is to slow the absorption and breakdown of drugs.
This way, your body absorbs them in the correct area of your bowel.
Without magnesium stearate, it would be hard to predict a medication's outcome, quality, and consistency.
Cosmetics. In the cosmetic world, magnesium stearate is a helpful ingredient for many things.
magnesium stearate acts as a bulking agent, an anti-caking agent, a colorant, and more.
Here, magnesium stearate is a low-hazard product, but data on this is limited.
Magnesium stearate is widely used in the production of dietary supplement and pharmaceutical tablets, capsules and powders as well as many food products, including a variety of confectionery, spices and baking ingredients.
Although considered to have a safe toxicity profile, there is no available information regarding its potential to induce genetic toxicity.
To aid safety assessment efforts, magnesium sulfate was evaluated in a battery of tests including a bacterial reverse mutation assay, an in vitro chromosome aberration assay, and an in vivo erythrocyte micronucleus assay.
Magnesium stearate did not produce a positive response in any of the five bacterial strains tested, in the absence or presence of metabolic activation.
Similarly, exposure to magnesium stearate did not lead to chromosomal aberrations in CHL/IU Chinese hamster lung fibroblasts, with or without metabolic activation, or induce micronuclei in the bone marrow of male CD-1 mice.
These studies have been used by the Japanese government and the Joint FAO/WHO Expert Committee on Food Additives in their respective safety assessments of magnesium stearate.
These data indicate a lack of genotoxic risk posed by magnesium stearate consumed at current estimated dietary exposures.
However, health effects of cumulative exposure to magnesium via multiple sources present in food additives may be of concern and warrant further evaluation.
Magnesium stearate is the magnesium salt of the fatty acid, stearic acid (Fig. 1).
Magnesium stearate has been widely used for many decades in the food industry as an emulsifier, binder and thickener, as well as an anticaking, lubricant, release, and antifoaming agent.
Magnesium stearate is present in many food supplements, confectionery, chewing gum, herbs and spices, and baking ingredients.
Magnesium stearate is also commonly used as an inactive ingredient in the production of pharmaceutical tablets, capsules and powders.
For food applications, magnesium stearate is typically manufactured by one of two processes.
The direct or fusion process involves direct reaction of fatty acids with a source of magnesium, such as magnesium oxide, to form magnesium salts of the fatty acids.
In the indirect or precipitation process, a sodium soap is produced by reacting fatty acids with sodium hydroxide in water and precipitating the product through addition of magnesium salts to the soap.
The fatty acids used as raw material are derived from edible fats and oils and consist mainly of stearic and palmitic acid.
The final product contains 4.0-5.0% magnesium, on a dried basis, and the fatty acid fraction is composed of ≥90% stearic and palmitic acids, at least 40% of which are stearic acid.
Magnesium stearate is a very fine powder that is greasy to the touch and practically insoluble in water.
Upon ingestion, magnesium stearate is dissolved into magnesium ion and stearic and palmitic acids.
Magnesium stearate is absorbed primarily in the small intestine, and to a lesser extent, in the colon.
Magnesium stearate is an essential mineral, serving as a cofactor for hundreds of enzymatic reactions and is essential for the synthesis of carbohydrates, lipids, nucleic acids and proteins, as well as neuromuscular and cardiovascular function .
The majority of magnesium content in the body is stored in bone and muscle .
A small amount (∼1%) is present in serum and interstitial body fluid, mostly existing as a free cation while the remainder is bound to protein or exists as anion complexes .
The kidney is largely responsible for magnesium homeostasis and maintenance of serum concentration .
Excretion occurs primarily via the urine, but also occurs in sweat and breast milk.
Stearic and palmitic acids are products of the metabolism of edible oils and fats for which the metabolic fate has been well established.
These fatty acids undergo ß-oxidation to yield 2-carbon units which enter the tricarboxylic acid cycle and the metabolic products are utilized and excreted .
All genotoxicity assays were GLP-compliant; however, analysis of dose formulations for concentration was not mandated by the Japanese regulatory agency requesting these studies and was not performed.
Magnesium stearate (99% relative content of stearic and palmitic acid;
CAS No. 557-04-0; San-Ei Gen F.F.I., Inc., Osaka, Japan) was stored at room temperature.
Formulations were prepared just prior to use by adding vehicle to the weighed test substance and solubilizing with ultrasound; lower concentrations were prepared by serial dilution.
Dimethyl sulfoxide (DMSO) was purchased from Sigma-Aldrich Japan K.K. (Shinagawa-ku, Japan). 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide (AF-2), 2-aminoanthracene (2AA), sodium carboxymethyl cellulose, and mitomycin C (MMC) were purchased from Wako Pure Chemical Industries, Ltd., Osaka, Japan.
9-Aminoacridine hydrochloride monohydrate (9AA) and N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) were purchased from Nacalai Tesque, Inc. (Kyoto, Japan).
Japanese Pharmacopeia saline was purchased from the Otsuka Pharmaceutical Factory, Inc
Magnesium stearate is a combination of stearic acid and the essential mineral magnesium.
Magnesium stearate’s a mixture of pure stearic acid and palmitic acid, where the content of stearic acid is not less than 40.0% and the sum of the two acids is not less than 90.0%.
The British Pharmacopoeia 1993 describes magnesium stearate as consisting mainly of magnesium stearate with variable proportions of magnesium palmitate and magnesium oleate.
Magnesium stearate is a form of chelated pre-acidified magnesium, and just like other chelated minerals (magnesium ascorbate, magnesium citrate, et al) has no inherent negatives based on its being in a stable neutral compound comprised of a mineral and an acid (vegetable-sourced stearic acid from palm oil neutralized with magnesium salts).
Magnesium stearate is a magnesium salt of fatty acids C16 to C18.
NOW uses stearates tested to U.S. Pharmacopeia monograph standards; known as pharmaceutical grade, the highest purity.
They are non-GMO, free from BSE/TSE, and may be used, if desired, as part of a vegetarian or vegan diet.
Inactive Ingredients
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Magnesium Stearate
Excipient (pharmacologically inactive substance)
Medically reviewed by Drugs.com. Last updated on Nov 9, 2020.
Magnesium stearate (Mg(C18H3502)2 or octadecanoic acid) is a solid, white powder at room temperature.
Magnesium stearate is a FDA-approved inactive ingredient commonly used in the pharmaceutical industry as a diluent for the manufacture of tablet, capsule, and powder dosage forms.
Magnesium stearate is generally recognized as safe by the FDA.
Magnesium stearate exists as a salt form and is useful for it's lubricating properties for capsules and tablets in industry.
Magnesium stearate is used to help prevent pharmaceutical ingredients from adhering to industry equipment.
Magnesium stearate may be derived from both plant and animal sources.
Magnesium stearate is found in many supplements because, during supplement manufacture, Magnesium stearate makes it easier to work with certain ingredients, making them flow more evenly and preventing them, as well as tablets, from sticking to machines during production.
Magnesium stearate is created from reacting stearate (from animal fats — often pig — or plant-based sources such as palm oil, coconut oil, or vegetable oil) with magnesium.
A very small amount is used in supplements, and it typically comprises less than 1% of a total formulation — less than 20 mg.
If it's in a product, you'll see it included in the "Other Ingredients" section of supplement labels.
Concerns have been raised that magnesium stearate can have negative effects, such as raising cholesterol levels, suppressing the immune system, creating biofilms in the body, and causing allergic reactions.
As discussed below, there is insufficient scientific evidence to justify these concerns.
Increasing cholesterol levels:
Concern has been raised about the stearic acid in magnesium stearate raising cholesterol levels, as stearic acid is a saturated fat.
This should not be a concern because even normal dietary intake of stearic acid has been shown to have no significant effect on total cholesterol, low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol levels .
In addition, the amount of stearic acid from magnesium stearate in supplements is very small.
According to USDA nutrition surveys, the average American adult consumes between 5,900 to 8,800 milligrams of stearic acid each day, typically from food sources like beef, poultry, cocoa butter, milk and cheese.
A single chocolate bar contains about 5,000 milligrams of stearic acid. Meanwhile, the amount of stearic acid in the magnesium stearate in a dietary supplement is generally less than 20 milligrams.
Magnesium stearate is the most commonly used metallic salt boundary lubricant containing two equivalents of a fatty acid (usually stearic and palmitic acid) and a charged magnesium .
Magnesium stearate is relatively inexpensive, chemically stable, has a high melting point and lubrication property.
A concentration of 0.25%–5.0% w/w magnesium stearate was used in formulation development .
Magnesium stearates lubricant effect relates to the adherence of the polar moiety on granules/powders, while the lipophilic moiety is oriented outward from the particle's surface .
Magnesium stearates capacity to form a hydrophobic (waxy) layer around particles leads to reduced water penetration, which compromises the dissolution profile.
Commercially available magnesium stearates are generally a mixture of crystalline forms (anhydrate, monohydrate, dihydrate, and trihydrate) .
The crystal structures identified for the magnesium stearate hydrates include the plate-shaped dihydrate and needle-shaped monohydrate and trihydrate forms .
The different crystalline forms have different strengths of attraction between adjacent lamellae, which affect its relative ability to delaminate and subsequently coat adjacent particles.
The monohydrate form produces tablets with lower variability .
The dihydrate form acts as a better lubricant because of its lamellar shape as it shears readily under applied tangential forces and because it has a lower tendency to cause over-lubrication .
The irregularity of the shapes of commercially available magnesium stearates compared to pure magnesium stearate relates to their reduced lubricant effects .
The amount and the mixing time of magnesium stearate in the formulation are critical variables.
A higher level and longer mixing time reduce the drug dissolution.
Depending upon the source, magnesium stearate differs in morphology, crystallinity, batch-to-batch variability in particle size, surface area, bulk strength, and fatty acid composition .
These differences can result in different compression profiles and lubrication efficiency that lead to differences in hardness and tablet friability.
Three factors: differences in chemical composition, specific surface area, and crystal structure, have considered being mainly responsible for these variations.
A composition consisting of magnesium stearate to palmitate in a ratio of 25%–75%, respectively, is optimum for its lubrication and shear properties, but this composition is generally not found in commercial samples.
The surface area of magnesium stearate is also an important variable and the greater the surface area, the higher the ability to coat other particles in the formulation, ultimately leading to an effective lubrication.
Magnesium stearate with impurities of magnesium oxide creates an alkaline environment, causing drug degradation, especially for base-sensitive molecules .
Kararli et al., reported that MgO reacts with ibuprofen at certain temperatures and humidity to form the magnesium salt of ibuprofen .
Magnesium stearate also induced an oxidation reaction, and the decomposition of drotaverine HCl was accelerated when magnesium stearate and talc were present in a formulation .
Specifically, drotaverine HCl was degraded to drotaveraldine by an oxidative degradation pathway, which can be inhibited using an antioxidant or an acidic auxiliary material.
Degradation of drugs also was mediated by the presence of magnesium ions.
Upon an accelerated stress treatment, fosinopril sodium was degraded into a β-ketoamide (III) and a phosphoric acid (IV) in a tablet formulation with magnesium stearate, mediated by magnesium metal ions .
magnesium stearate (Mg(C17H34COO)2, CAS Reg. No. 557-04-0) is the magnesium salt of stearic acid.
It is produced as a white precipitate by the addition of an aqueous solution of magnesium chloride to an aqueous solution of sodium stearate derived from stearic acid that is obtained from edible sources and that conforms to the requirements of § 172.860 of this chapter.
The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed.
(1981), p. 182, which is incorporated by reference. Copies are available from the National Academy Press, 2101 Constitution Ave. NW., Washington, DC 20418, or available for inspection at the National Archives and Records Administration (NARA).
In accordance with § 184.1, the ingredient is used in food with no limitation other than current good manufacturing practice.
The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the following current good manufacturing practice conditions of use:
The ingredient is used as a lubricant and release agent as defined in § 170.3 of this chapter; a nutrient supplement as defined in § 170.3 of this chapter; and a processing aid as defined in § 170.3 of this chapter.
The ingredient is used in foods at levels not to exceed current good manufacturing practice.
Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.
Magnesium stearate is a magnesium salt of stearic acid.
Essentially, it’s a compound containing two stearic acids and magnesium.
Stearic acid is a saturated fatty acid found in many foods, including animal and vegetable fats and oils.
Cocoa and flaxseeds are examples of foods that contain substantial amounts of stearic acid.
After magnesium stearate is broken back down into its component parts in the body, its fat is essentially the same as that of stearic acid.
Magnesium stearate powder is often used as an additive in dietary supplements, food sources and cosmetics.
Magnesium stearate is the most common ingredient used in forming tablets because it’s an effective lubricant.
It’s also used in capsules, powders and in many food products, including a host of confectionary, chewing gum, herbs and spices, and baking ingredients.
Known as a “flow agent,” it helps speed up the manufacturing process because it prevents ingredients from sticking to the mechanical equipment.
Just a minuscule amount is required to coat a powder blend of virtually any drug or supplement mixture.
It also works as an emulsifier, binder, and thickening, anticaking, lubricant, release and antifoaming agent.
Not only is it fantastic for manufacturing purposes because it allows for smooth transport on the machines that produce them, but it makes the pill easier to swallow and move down the gastrointestinal tract.
Magnesium stearate is also a common excipient, which means it helps enhance the therapeutic effect of the active ingredient of various medications to promote drug absorption and solubility.
Known as safe vehicles for drugs, excipients also help give pills a uniform consistency.
Some claim that it’s possible to produce a drug or supplement without excipients like magnesium stearate, which begs the question why they’re used when more natural alternatives are available.
But that may not be the case.
Magnesium stearate is the salt of a complex mixture of fatty acids, with the majority being stearate and palmitate.
Magnesium stearate has multiple crystalline forms and, potentially, an amorphous form.
Magnesium stearate is used in the pharmaceutical manufacturing industry as a powder lubricant, and typically is added at low levels (∼1%) during the manufacturing process and blended for a relatively short time (∼5 min).
Proper levels and mixing times are needed, as too short a mixing time or too small a quantity will result in improper lubrication, and too much can negatively impact dissolution rates.
The complex mixture of multiple fatty acids and crystalline forms in magnesium stearate leads to variability between commercial sources, and switching between sources can impact both the amount of lubricant and mixing time needed for proper lubrication.
In order to better understand the complex nature of magnesium stearate, a variety of analytical techniques were used to characterize both synthesized and commercial magnesium stearate samples.
The results show that correlation among differential scanning calorimetry, thermogravimetric analysis, solid-state NMR spectroscopy, and other techniques provides a unique insight into the forms of magnesium stearate.
Finally, the ability to monitor form changes of magnesium stearate in an intact tablet using solid-state NMR spectroscopy is shown.
Solid oral dosage forms such as tablets are the most commonly used method for drug delivery.
Tablets have many advantages including ease of storage, long-term stability, and the relative ease of manufacturing.
The manufacturing of a tablet is a complex multistep process that requires control of each unit operation to ensure the highest bioavailability of the drug molecule.
One example of a unit operation that can affect product quality is that, prior to tablet compression, the materials are mixed to add a lubricant, allowing for the tablets to be ejected easily from the tablet die.
Careful monitoring of the lubrication step is important, because too little lubricant can lead to tableting issues (picking and sticking, hardness, etc.) while too much lubricant can lead to bioavailability issues (poor dissolution, etc.).
One of the most widely used lubricants is magnesium stearate (MgSt).
Magnesium stearate is found in 108 of the top 200 formulations currently in the market, due to its ability to decrease friction between the tablet and the die during tabletting.
Magnesium stearate is hydrophobic and can coat the surface of the active pharmaceutical ingredient, inhibiting dissolution and lowering bioavailability.
The lubricating properties of Magnesium stearate and how it is affected by the hydration state of MgSt have been studied a great deal because it was originally discovered as a potential pharmaceutical lubricant by Hanssen et al.
Although Magnesium stearate is widely used and has been studied extensively, the complexity of the material means that it is still not very well understood.
There are 5 different solid-state forms of Magnesium stearate, including an anhydrous form, 2 monohydrate forms, (corresponding to the location of crystalline disorder), a dihydrate, and a trihydrate form.
Magnesium stearate samples can contain a single crystalline form, or mixtures of 2 or more forms.
Identifying and quantifying the mixtures can be challenging as techniques such as differential scanning calorimetry (DSC) may produce a complex thermogram that is difficult to interpret.
Moreover, thermogravimetric analysis (TGA) may provide information about the total water content, but not about where the water is located in the crystal lattice.
In addition to the numerous crystalline forms, the fatty acid composition can vary greatly.
Magnesium stearate should be noted that although Magnesium stearate is the salt of the fatty acid (e.g., stearate) that is present in Magnesium stearate, the fatty acid component is often described using the acidic form (e.g., stearic acid), and will be described here using either terminology.
Although there are 2 different sources of the fatty acids that are used to make Magnesium stearate (animal and plant), only plant-based Magnesium stearate is used in pharmaceutical formulations.
Magnesium stearate is not only comprised of magnesium and stearic acid (C18:0), but a range of other fatty acids as well.
According to United States Pharmacopeia standards, Magnesium stearate must contain at least 40% stearic acid, and >90% must be a combination of stearic (C18:0) and palmitic acid (C16:0) (in terms of fatty acid concentration only).
The other 10% of the sample can include any number of different chain length fatty acids (myristic, margaric, arachidic, etc.).
Even though the fatty acid content varies between form and manufacturer, most Magnesium stearate still exists as a crystalline material, forming crystals similar to a lipid bilayer with the magnesium ions in the “hydrophilic” region.
Water molecules are proposed to attach between and around the magnesium ions allowing for the formation of the hydrates mentioned above.
As mentioned above, multiple studies have focused on obtaining a better understanding of the complexities of Magnesium stearate as a lubricant because it was originally discovered as a potential lubricant by Hanssen et al.
There have been numerous attempts to fully understand Magnesium stearate in formulations, including multiple studies using Raman spectroscopy to monitor Magnesium stearate in both blends and tablets.
Raman mapping has proven useful in the visualization of the coating of microcrystalline cellulose particles by Magnesium stearate, but quantitative data were not possible with that experimental approach.
Many of the investigations have searched for a link between the structure and the functional properties.
In a study by Leinonen et al., Magnesium stearate was discovered that surface area and particle size significantly affect the lubricity between the commercial sources, but reduced lubricity of an Magnesium stearate sample prepared using only stearic acid could not be explained.
York and coworkers were some of the first to complete extensive work on Magnesium stearate.
The initial works from the York group was focused on extensive characterizations of synthesized Magnesium stearate, although only the dihydrate form was investigated.
These works attempted to understand how the synthesis affected the formation of pure Magnesium stearate and magnesium palmitate, and eventually led to more detailed work investigating the frictional properties of the powders.
Further work by York and coworkers involved investigating the influence of Magnesium stearate on an active pharmaceutical ingredient during tableting and its influence on the dissolution of the drug.
One of these works discovered that commercial Magnesium stearate samples affect the dissolution of active pharmaceutical ingredient, while the dissolution remained unchanged when using laboratory synthesized pure stearate samples.
Other works by York and coworkers explored how the lubricant coated the particles during tableting.
One aspect of Magnesium stearate that was overlooked in many of the above works was the effect of moisture on the lubricating ability, which was discovered by Mueller et al.
These findings have resulted in many groups choosing to investigate the polymorphism/hydrate formation (specifically hydration state) of Magnesium stearate.
One of these studies, by Brittain and coworkers, focused on the preparation of MgSt samples from chemically pure stearic and palmitic acids to study the range of hydration formation.
Brittain and coworkers were able to analyze the anhydrate, dihydrate, and trihydrate forms of pure MgSt and magnesium palmitate by DSC, powder X-ray diffraction (PXRD), and microscopy.
The analytical and thermal investigation showed that the dihydrate form contained more tightly bound water than the trihydrate.
The polymorphism of MgSt had been studied before the Brittain article was published, but not to the level of detail presented in that article.
Bansal and coworkers published a similarly detailed manuscript in 2005 focusing on the effects of solid-state properties on the lubrication properties of Magnesium stearate.
In that paper, the authors were able to characterize different Magnesium stearate lots by particle size, shape, specific surface area, optical microscopy, DSC, TGA, Fourier transform infrared spectroscopy, and PXRD, and found that hydrate form played a role in its solid-state characteristics.
A comparison of the samples and their lubrication performance suggested that smaller particle size, larger specific surface area, and plate-like crystal habit were more important than molecular-level characteristics (dihydrate forms, water in 2 thermodynamic states, and larger d spacing).
This work by Bansal and coworkers sheds light on the possible causes for some of the issues observed when using MgSt as a lubricant.
In this article, we have investigated the variability that exists in Magnesium stearate samples using advanced analytical techniques to characterize the materials.
Surprisingly, there have been relatively very few studies that look solely at Magnesium stearate, and only one that incorporates 13C solid-state NMR (SSNMR) spectroscopy, a nondestructive and quantitative technique that can provide detailed information about structure, miscibility, mobility, solid-state interactions, and form quantification.
We have found that SSNMR can provide unique insight into the crystalline forms of Magnesium stearate, and that the results correlate well with other analytical techniques such as DSC, TGA, and PXRD.
In particular, the crystalline forms of Magnesium stearate can be both identified and quantified.
Finally, we show how 13C labeling of MgSt can be used to study the form changes of MgSt in formulated products
Magnesium stearate is a simple salt made of two common nutritional substances, the mineral magnesium and the saturated fat stearic acid.
Magnesium stearate is used as a flow agent, lubricant, binder or anti-caking agent in the production of many nutritional supplements and pharmaceuticals.
Magnesium and stearic acid are bound together to create magnesium stearate.
We all know what magnesium is… it’s an essential mineral abundant in dark green leafy vegetables.
Stearic acid is a saturated fatty acid found in many foods including eggs, chicken, grass-fed beef, coconut oil, walnuts, cheese, chocolate, salmon and human breast milk, to name just a few.
Magnesium stearate is generally known that hydrophobic lubricants such as magnesium stearate can have a strong negative effect on the binding properties of directly compressible filler-binders.
Magnesium stearate was found that the decrease in binding forces is not only dependent on the tablet ingredients and the lubricant concentration used, but especially on the mixing time and mixing procedure.
Most studies were performed, however with small laboratory scale mixers.
In order to evaluate the effect of magnesium stearate admixing in different types of laboratory-scale and industrial mixers, the decrease in crushing strength was measured for a test formulation during mixing with the lubricant in different mixers.
The formula used consisted of 90% a-lactose monohydrate 100 mesh, 9.5% microcrystalline cellulose and 0.5% magnesium stearate.
The mixers used were two laboratory scale mixers: a 2 litre Turbula mixer and a 13 litre cubic mixer and five production scale mixers:
a 45 litre drum mixer, 90 litre, 200 litre and 900 litre planetary mixers and a 1.000 litre V-shaped mixer, respectively.
For the test formulation used, Magnesium stearate was found that the effect of lubricant admixing on tablet crushing strength was strongly dependent on type, size and rotation speed of the mixer used.
When operated at the same rotation speed, the decrease in crushing strength was much faster for the large industrial mixers than for the small laboratory mixers.
These differences were explained by differences in shear forces during the mixing process and the efficiency of the mixing procedure.
For the industrial mixers the decrease of the tablet crushing strength as an effect of lubricant admixing was mainly determined by the rotation speed and only to a small extent by the type and size of the apparatus.
Moreover no effect of load could be observed between the mutual industrial mixers used.
For a prediction of the effect of lubricant admixing on tablet crushing strength in large mixers, efficient laboratory mixers, operating at high rotation speeds can be used.
For this purpose a 2 litre Turbula mixer is a valuable tool in preformulation work.
Magnesium stearate or "mag stearate" for short is just a chemical used by most nutritional supplement companies, and it's an additive.
Magnesium stearate acts like a lube to run machines faster, so as to increase production and therefore profits.
This substance consists of magnesium and stearate which is a saturated fat.
Think of it like bubble wrap around the ingredients of your supplement.
Magnesium stearate doesn't function as a vitamin or mineral, and more importantly, it doesn't give you "magnesium" like the name implies.
Your body requires biochemical 'work' to pop the 'bubble wrap' and split the molecule apart into its backbone of magnesium and stearic acid.
Once split, you get a negligible amount of magnesium, perhaps a couple of milligrams.
So mag stearate is not a source of magnesium for your body, don't be fooled by the name.
Therapeutic doses of magnesium fall into the 200-800 mg range.
If you read the labels of your supplements and see magnesium stearate, you should know:
Magnesium stearate's not a source of magnesium for your body, don't be fooled by the name.
Magnesium stearate's a mechanical lubricant intended to grease machines for faster production.
Magnesium stearate has no nutritional value.
Magnesium stearate's an additive.
Sometimes sourced from genetically engineered hydrogenated oils.
Magnesium stearate may affect the release time of active ingredients and slow it down
Magnesium stearate may reduce bioavailability of active ingredients, certainly makes it unpredictable.
Magnesium stearate's sort of like "grease" it affects the digestive tract in sensitive folks.
The sales people at the local store are often very intelligent, but they don't always agree with me about mag stearate.
Remember, Magnesium stearate's in almost every supplement made, and concealed with aliases like "stearic acid" or "vegetable stearate" and others.
Most sales clerks will tell you Magnesium stearate's present in the supplement to give you "magnesium," but as you've learned, this is not true.
The one and only purpose for Magnesium stearate's use is to aid in the manufacturing process.
This is not a toxic ingredient as far as I'm concerned, I'm just saying that Magnesium stearate's not good for you since it does not add any nutritional value and it may hinder absorption of the ingredients.
No one can agree on this.
In 2011, a World Health Organization report found cross-contaminants such as bisphenol A (BPA) and Irganox 1010 used in plastics in a few batches of mag stearate.
Even though this happened once, and never again, you deserve to know.
I certainly don't mean to alarm you or have you throw out every single supplement in your cupboard, but there's nothing wrong with upgrading your formulas one by one.
IUPAC NAME:
magnesium bis(octadecanoate)
magnesium dioctadecanoate
Magnesium distearate
magnesium distearate
Magnesium octadecanoate
magnesium octadecanoate
Magnesium Octadeconoate
MAGNESIUM STEARATE
Magnesium stearate
Synonyms:
209-150-3
3919702
557-04-0
70097M6I30
Dibasic magnesium stearate
Dioctadécanoate de magnésium
Magnesium dioctadecanoate
MAGNESIUM OCTADECANOATE
Magnesium stearate
