LUBRICANTS:

Magnesium Stearate (and Calcium Stearate):

Water Solubility: Insoluble
Conc. Use Range: 0.25 - 1.5%

Magnesium stearate is the most commonly used and most effective of all lubricants. It is also the most likely to cause compression & dissolution problems. Concentration, grade and mixing parameters must be carefully controlled. These stearates are alkaline in reaction. Incompatible with strong acids, alkalis, and iron salts. Avoid mixing with strong oxidizing materials.Magnesiumstearate cannot be used in products containing aspirin, some vitamins, and most alkaloidal salts.. Magnesium stearate has good glidant and anti-adherent properties.

Stearic Acid:

Water Solubility: Insoluble
Conc. Use Range:1 - 4%

Not as effective a lubricant as Magnesium Stearate. Mixing times not as critical. Incompatibilities include some alkaline salts such as sodium saccharin and sodium Phenobarbital, also incompatible with most metal hydroxides and may be
incompatible with bases, reducing agents, and oxidizing agents.

Hydrogenated Vegetable Oil (Sterotex, Lubritab, Cutina):

Water Solubility: Insoluble
Conc. Use Range: 2 - 5%

Solid at room temperature, these materials melt at compression pressures and temperatures to impart a lubricating effect. Vegetable oil usually used in combination with talc, silica or a silicate to prevent sticking to tablet punch faces. Incompatible with strong oxidizing agents.

Mineral Oil:

Water Solubility: Insoluble
Conc. Use Range: 1 - 3%

Light mineral oil is an efficient lubricant. But since it must be finely sprayed onto granules and powders to be used, it also can cause noticeable mottling or spotting on tablet surfaces. For these reasons, it is not commonly used anymore. But can still be found in some formulations.

Polyethylene Glycol 4000 -6000 (PEG):

Water Solubility: Soluble
Conc. Use Range: 2 - 5%

Has been used as a water-soluble lubricant for some water soluble and effervescent tablet formulations. Fairly high concentration and low particle size needed to be moderately effective as a lubricant. It has no glidant or anti-adherent properties.

Sodium Lauryl Sulfate (SLS):

Water Solubility: Soluble
Conc. Use Range: 2 - 3%

Effective at reducing ejection forces but does not help much for sticking to punch faces. Therefore, it must be used in conjunction with an anti-adherent. magnesium ions.Sodium lauryl sulfate is incompatible with salts of polyvalent metal ions, such as aluminum, lead, tin or zinc, and precipitates withpotassium salts.

Glyceryl Palmitostearate (Precirol) & Glyceryl Behenate (Compitrol 888):

Water Solubility: Insoluble
Conc. Use Range: 2 - 5%

Glyceryl palmitostearate is used in oral solid-dosage pharmaceutical
formulations as a lubricant. Disintegration times increase and tablet strength decreases with increase in mixing time. Glyceryl palmitostearate is incompatible with ketoprofen and naproxen.
In pharmaceutical formulations, glyceryl behenate is mainly used as a lubricant in the preparation of oral tablets and capsules. It has good binding properties, it does not affect tablet hardness and is,unaffected by mixing or production parameters.

Sodium Stearyl Fumarate (Pruv):
Water Solubility: Soluble
Conc. Use Range: 0.5 - 2%

Sodium stearyl fumarate is reported to be incompatible with chlorhexidine acetate.




ANTIADHERANTS and GLIDANTS:

Talc:

Water Solubility: Insoluble
Conc. Use Range: 1-10%

Not particularly effective on its own as a tablet lubricant or glidant. But very effective with lubricants in the role of an anti-adherent in that it effectively prevents sticking to surfaces. When using talc, it should always be blended into the formulation first followed by the lubricant (i.e. magnesium stearate). Talc incompatible with quaternary ammonium compounds.

Fumed Silicon Dioxide (Cab-o-sil):

Water Solubility: Insoluble
Conc. Use Range: As anti-adherent, 1-2% As glidant, 0.1 - 0.5%

Fumed Silicon Dioxide has no lubricant properties. It is commercially available as very fine particles (approx. 0.014 microns), which tend to agglomerate into “balls”.
It functions by coating granules, etc. and reducing interparticulate friction of these thereby improving flow characteristics. For processing, this material must be screened into a batch. However, due to the extremely fine particle size, it should be pre-blended with another component to facilitate screening and distribution. It is an extremely effective glidant at low concentrations, and has anti-adherent properties at higher concentrations. However at higher concentrations, flow characteristics may actually be impeded resulting in an increase in weight variation. Colloidal silicon dioxide is hygroscopic but adsorbs large quantities of water without liquefying.

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