Tablet massing process

Water Uptake. There is evidence to suggest that water uptake caused by capillary forces is the crucial factor in the disintegration process of many formulations. In such systems the pore structure of the tablet is of prime importance and any inherent hydrophobicity of the tablet mass will adversely affect it. Therefore, disintegrants in this group must be able to maintain a porous structure in the compressed tablet and show a low interfacial tension towards aqueous fluids. Rapid penetration by water throughout the entire tablet matrix to facilitate its breakup is thus achieved. Concentrations of disintegrant that ensure a continuous matrix of disintegrant are desirable and levels of between 5 and 20% are common. 

Normally, the lubricants present in the tableting mass also act as antiadherents, but in the worst cases it may be necessary to add more starch or even talc to overcome the defect. So by judicious choice of a combination of excipients, all of these undesirable effects of the tableting process can be minimized. 

The tablet mass was fixed at 200 mg. Each unit contained 10 mg (5%) drug and 1.2% lubricant. It was considered that the lubricant level could be adjusted and optimized later as part of a process study. Thus, although there were 5 components in the mixture, 2 of them were fixed. The factor space in the remaining components, microcrystalline cellulose, lactose, and carbomer (totalling 93.8%) can be represented as a ternary diagram. The tablets were manufactured by direct compression of the powder mixture and the dissolution profiles were measured at pH 2 (0.01 M hydrochloric acid) and pH 7 (phosphate buffer). The time for 50% dissolution was measured in each case. 

Freshly prepared starch paste is used at a concentration of 5-25% (w/w) in a tablet granulation. Relatively soft and friable granules are produced when starch paste is used as a binder. Consequently, it yields tablets that disintegrate readily. During the wet-massing process, high viscosity of the starch paste can sometime make it difficult to evenly distribute the binder in the powder blend. 

An investigation into the determination of degradation products by NIR was published in 1990 by Drennen and Lodder [84]. The major degradation process in aspirin tablets is the hydrolysis of aspirin to salicylic acid. One of two USP methods must be performed to verify tablet aspirin content and both are time-consuming. A second analysis by HPLC must be performed to verify that salicylic acid levels do not exceed 0.3% of the tablet mass. 

For most tablets, it is necessary to overcome the cohesive strength introduced into the mass by compression. It is therefore common practice to incorporate an excipient, called a disintegrant, which induces this process. Several types, acting by different mechanisms, may be distinguished (a) those that enhance the action of capillary forces in producing a rapid uptake of aqueous liquids, (b) those that swell on contact with water, (c) those that release gases to disrupt the tablet... 

Measurement of the punch and die forces plus the relative displacement of the punches can provide raw data which, when suitably processed and interpreted, facilitate the evaluation of many tableting parameters. Many of the workers first involved in instrumenting tablet presses concentrated on deriving relationships between the applied force (FA) and the porosity (E) of the consolidating mass. 

Density is defined as the ratio of the mass of an object to its volume. It is dependent on the type of atoms in the molecule, as well as the arrangement of the atoms in the molecule and the arrangement of molecules in the sample. In a solid, the arrangement of the molecules, and therefore the density, is related to the crystalline nature of the compound. The density of a powder or granulation can affect a number of pharmaceutical processes, including flow, mixing, and tableting. 

Suppose you are analysing a number of samples of ground nutrient tablets to determine their iodine content. The method is very simple. A known mass of each sample is taken, processed to isolate the iodine,... 

Solidifying the coating through a solvent removal (drying) process Coating tablets en masse... 

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