Lubricant, tablet

Compressed tablet formulations contain different types of ingredients necessary for proper preparation and therapeutic performance. The ingredients needed include diluents, disintegrating or binding (adhesive) additives, and lubricants. Tablets are designed to be dissolved slowly in the mouth and should not disintegrate quickly. Lactose... 

Chem. Descrip. Hydrogenated cottonseed oil CAS 68334-00-9 EINECS/ELINCS 269-804-9 Uses Tableting aid for pharmaceuticals (tablet lubricant, tablet coating, sustained release) lubricant for pressed powds. 

Formulation. Compressed tablet formulations contain several types of inert, adjuvant ingredients necessary for proper preparation and therapeutic performance. Tablets designed to be swallowed need diluent, disintegrating, binding (adhesive), and lubricating inert ingredients, whereas... 

Ghdants are needed to faciUtate the flow of granulation from the hopper. Lubricants ensure the release of the compressed mass from the punch surfaces and the release/ejection of the tablet from the die. Combinations of siUcas, com starch, talc (qv), magnesium stearate, and high molecular weight poly(ethylene glycols) are used. Most lubricants are hydrophobic and may slow down disintegration and dmg dissolution. 

Cosmetics. Talc is widely used in baby and body powders, pressed powders, creams, and antiperspirants. Its softness, sHp, inertness (fragrance retention), and relative safety make this one of the oldest and most widely recognized appHcations for talc. Talc is also used in chewing gum as a detackifier and in tableting as a lubricating process aid. 

Binders improve the strength of compacts through increased plastic deformation or chemical bonding. They may be classified as matrix type, film type, and chemical. Komarek [Chem. Eng., 74(25), 154 (1967)] provides a classification of binders and lubricants used in the tableting of various materials. 

The Cadila system [13] has been designed to formulate tablets for drugs based on their physical (solubility, hydroscopicity, etc), chemical (functional groups), and biologically interrelated (dissolution rate) properties. The system first identifies the desirable properties for optimum compatibility with the drug, selects those excipients that have the required properties, and then recommends proportions based on the assumption that all tablet formulations comprise at least one binder, one disintegrant, and one lubricant. Other... 

Tablet Formulations (Immediate Release). Two papers in the mid-1990s reported the earliest studies on immediate release tablets. In the first, tablet formulations of hydrochlorothiazide [33] were modeled in an attempt to maximize tablet strength and select the best lubricant. In the other, a tablet formulation of caffeine was modeled [34] to relate both formulation and processing variables with granule and tablet properties.

Pellets or tablets (1.5-10 mm in diameter), rings (6-20 mm) and multichanneled pellets (20-40 mm in diameter and 10-20 mm high) are used when a high mechanical strength is required. They are produced by compressing a mixture of the support powder and several binders (kaolin day, stearic acid) and lubricants (graphite) in a press. 

Fig. 16 Effect of lubricant on dissolution of rate of salicylic acid contained in compressed tablets, x, 3% magnesium stearate , no lubricant 0> 3% sodium lauryl sulfate. (From Ref. 21.).

G. Levy and R. H. Gumtow, Effect of certain tablet formulation factors on dissolution rate of the active ingradient. III. Tablet lubricants, J. Pharm. Sci., 37. 52,1139-1141 (1963). 

Incompatibilities have also been observed in solid dosage forms. A typical tablet contain binders, disin-tegrants, lubricants and fillers. Compatibility screening for a new drug should consider two or more excipients from each class. Serajuddin et al. have developed a drug-excipient compatibility screening model to predict interactions of drug substances with excipients [49],... 

Lubricant for capsules and tablets, viscosity-imparting agent, drying agent for powder... 

Few tablets intended for oral administration are totally soluble in aqueous media, but if such a product is needed, then soluble excipients are employed. These include dextrose, lactose, mannitol, and sodium chloride, with the last of these sometimes acting as its own lubricant. Urea may also be used, but due to its known pharmacological effects, it is less desirable than the other soluble compounds cited. 

Insoluble Lubricants. Lubricants act by interposing an intermediate layer between the tablet constituents and the die wall. The smaller the amount of stress needed to shear the material, the better its lubricant properties will be. Since they are primarily required to act at the tooling/material interface, lubricants should be incorporated in the final mixing step after all granulation and... 

Some of the more common antifrictional agents are listed in Table 10. Many of these are hydrophobic and may consequently affect the release of medicament. Therefore, lubricant concentration and mixing time should be kept to the absolute minimum. Lubricants may also reduce significantly the mechanical strength of the tablet (see Fig. 12) [29,81]. Stearic acid and its magnesium and calcium salts are widely used, but the... 

Liquid paraffins, particularly those of low viscosity, have been used and are said to be of value for colored tablets, and even the use of modified vegetables has been attempted. However, they appear, in general, to offer little advantage over solid lubricants, and their incorporation into the precompression mixture is more difficult, requiring solution in a volatile liquid that is then sprayed onto the unlubricated material. Due to handling and EPA requirements, these materials are often rejected in the preformulation stage. 

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