Tablet manufacture methods

Direct compression is a simpler alternative tablet manufacturing method. With direct compression, tablets are compressed directly from a powder mixture of an API and appropriate excipients. Like granulation methods, this approach is also based on the required flow, compressibility, and compactibility of a formulation. Direct compression offers both time and economic advantages by eliminating intermediate granulating and drying steps. 

Hydrophilic matrix tablets are manufactured using traditional tablet manufacturing methods of direct compression (DC), wet granulation or dry granulation (roller compaction or slugging) depending on formulation properties or on manufacturer s... 

United States Patent 4489504. Steam granulation apparatus and method. http //www.pharmaprdia.com/Tablet manufacturing method/Granulation. 

SS Kornblum, JO Hirschorn. Dissolution of poorly water-soluble drugs I. Some physical parameters related to method of micronization and tablet manufacture of a quinazolinone compound. J Pharm Sci 59 606-609, 1970. 

The tablet was introduced by Thomas Brockedon in 1843, and glyceryl trinitrate tablets appeared in the British Pharmacopoeia of 1885. Since that time, many variations have appeared but the basic process remains unchanged. There are three main methods of tablet manufacture, with choice depending on the dose and the drug s physical properties such as compressibility and flow (Figure 2.2). A drug with a large... 

TABLE 5.4 Process Parameters and Uniformity Data for Tablets Manufactured Using Different Granulation Methods... 

Brake, E. F. (1951), Development of methods for measuring pressures during tablet manufacture, M.S. thesis, Purdue University, West Lafayette, IN. 

Tablet. 1 gives some of the general requirements expected of a chemical finish. As can be seen, they can be quite daunting. One future challenge for chemical finishing is the ever increasing concern over environmental and ecological issues. Traditional chemistries and manufacturing methods must be changed and modified to meet the new realities of our modem world.

Tablets can also be photostabilized using aluminum blister packs. This photostabilization method is used by some nifedipine tablet manufacturers. Nifedipine tablets packaged in aluminum foil unit dose blisters do not require any additional photo protection (e.g., coating), providing a significant saving in development and manufacturing costs as well as stability testing (40).

Several predictive methods have been applied to the tablet compaction process on a small scale to envisage what will happen on a large scale. Dimensional analysis has been described by Levin as a method of developing functional relationships that describe any given process in a dimensionless form to facilitate modeling and scale-up (or scale down). Although, theoretically, dimensional analysis can be applied to tablet manufacture, no examples are found in the literature. 

Both wet and dry granulation methods of tablet manufacture are complex multistage processes, but are necessary to convert the components of the formulation into a state that can be readily compressed into acceptable tablets. If, however, a major component of the formulation already possesses the necessary degree of fluidity and compressibility, granulation would be unnecessary. This is the basis of the direct compression method of tablet manufacture. ... 

In view of the apparent simplicity of this method of tablet manufacture and the number of suitable... 

There are three methods of tablet manufacture designed to confer these essential attributes to a tablet formulation. Wet granulation and direct compression are the most important, with dry granulation (also known as precompression or slugging) used in some circumstances. Fig. 1 shows the processes of wet granulation and direct compression broken down into their constituent stages. 

If a major component of the formulation such as the diluent were to possess the necessary degrees of fluidity and compressibility, granulation would be unnecessary. This is the basis of the direct compression method of tablet manufacture. 

A faulty batch of tablets can sometimes be recovered by grinding up the tablets and recompressing them, a process which is known as reworking and is analogous to the dry granulation method of tablet manufacture. This can sometimes cause problems with a direct compression formulation. Many direct compression diluent particles are in the form of aggregates, e.g., spray-dried lactose is composed of small crystals of lactose embedded in amorphous lactose. If these aggregates are compressed, their structure may be broken down to such an extent that subsequent recompression will result in impaired tablet quality. 

Schmidt PC, Vortisch W. Influence of manufacturing method of fillers and binders on their tableting properties comparison of 8 commercially available sorbitols [in German]. Pharm Ind 1987 49 495-503. 

Kornblum SS and Hirschorn JO. Dissolution of Poorly Water-Soluble Drugs. 1 Some Physical Parameters related to Method of Micronization and Tablet Manufacture of a Quinazoline Compound./PAarro Sci 1970 59 606-609. 

In the second method, the amount of Form C transformed from Form A at 45°C was about two times larger than that at 0°C at the same compression energy. The crushing strength of tablets prepared from Form A was about twice that of tablets manufactured using Form C as the source of drug substance. 

Figures 9.11 and 9.12 illustrate how changing the concentration of disintegrant (Veegum) in a tolbutamide tablet formulation can greatly alter bioavailability. A comparison of the commercial product (Orinase) with an experimental formulation that was identical in composition and manufacturing method but contained only 50% of the disintegrant (Veegum) showed that the commercial product displayed higher blood concentrations and greater ability to lower blood glucose than the experimental product.

Wet granulation and direct compression are two methods used to manufacture tablets in the pharmaceutical industry. Zomer et al. used pyrolysis-gas chromatography-mass-spectrometry coupled with SVM classification to discriminate between the two tablet production methods.Mass spectra data were submitted to a PCA analysis, and the first principal components were used as input for SVM models having linear, polynomial, and Gaussian RBF kernels. SVM classifiers with polynomial and RBF kernels performed better in prediction than discriminant analysis. 

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