Tablet by direct compression

Shangraw RF. Compressed tablets by direct compression. In Leiberman HA, Lachman L, Schwatz JB, eds. Pharmaceutical Dosage Forms Tablets. New York Marcel Dekker, Inc., 1990 195-246. 

Controlled-Release Tablet by Direct Compression and Wet Granulation... 

Saleh, S.I. Aboutaleb, A. Kassem, A.A. Stamm, A. A contribution to the formulation of effervescent tablets by direct compression. Labo-Pharma Probl. Tech. 1984, 32,163-166. 

Vennat, B. Gross, D. Pourrat, A. Pourrat, H. A dosage form for procyanidins high-dose tablets by direct compression. S.T.P. Pharma. 1988, 4 (5), 378-383. 

Conte, U., Colombo, P., Caramella, C. and La Manna, A. (1979) Sustained release nitrofurantoin tablets by direct compression. Farmaco [Prat], 34, 306-316. 

Calcium monohydrogen phosphate dihydrate Calcium phosphate, dibasic, dihydrate Dicalcium phosphate dihydrate Phosphoric xid, caicium salt (1 1), dihydrate. Dibasic calcium phosphate dihydrate USP/BP excipient tor production of pharmaceutical tablets by direct compression process. Penwest Pharmaceuticals Co. 

Lubricant Potential of Stearic Acid AND Derivatives for the Production Tablets by Direct Compression... 

Prolonged release from compressed hydrophilic matrices is dependent on the rate and extent the cellulose excipient hydrates in forming an external pseudo-gel layer. Earlier investigations performed in this laboratory [33] have shown for example that not all the water-soluble ethers are convenient for preparation of tablets by direct compression that will remain coherent for many hours when in contact with water (Table 8). 

The four starches used in this study have been proven to be suitable tablet ingredients [19]. Both used super-disintegrants, Primojel (sodium starch glycolate) and Polyplasdone XL (crospovidone), are commonly used as a disintegrant in tablets prepared by direct compression. 

Shallow convex tablets (jin) containing 300 mg HPMC K15M and 1% magnesium stearate were prepared by direct compression. Disintegration tests were performed in triplicate, using the BP 1988 method, in 600 ml of media at 37°C using discs. Tests were run for a maximum of 2 h. 

In previous work, the formula used were optimized by direct compression [13]. The area under the dissolution curve was optimized and validated by a composite design. However, the formulation gave poor powder flow as well as variability in the dissolution parameters. Thus the double compression process was investigated in order to change the powder into solid aggregates and therefore to enhance homogeneity, density and powder flow in addition it was expected that this process would reduce the variability between tablets. 

With the exception of the formulation obtained by direct compression in a rotary machine, the dissolution profiles were well fitted by the Weibull function. A high density in the centre of the tablets may explain the sigmoid dissolution profiles. A percentage of the drug remains imprisoned in the matrix after the dissolution test. It is possible to suppose that, in the densified central zone of the tablet, the diameters of the pores are smaller than the diameters of the drug particles covered by the inert polymers. 

The tablets obtained by direct compression in a single punch machine (Frogerais) and those obtained by wet granulation had very similar values only the coefficient of variation differentiate these two processes. 

A significant difference was found between tablets for the formulations obtained by direct compression in a rotary machine and by separate compaction. 

The first component, which expresses the curve shape, exhibits an opposition of the release profiles obtained by wet granulation and by direct compression. The wet granulation profile has a sigmoid aspect while the direct compression profiles, particularly those for the tablets obtained in rotary machine, are nearly linear. 

The plots of two components obtained from PCA and lfom discriminant analysis, revealed an opposition between tablets obtained by wet granulation and by direct compression. In fact, the principal component represents the curve shape of the dissolution profiles (P), which, in these two processes, were quite different. 

In summary, when tested, the grades of calcium phosphate dibasic discussed above exhibited mechanical properties that were very appropriate for tablet compaction and thus for formulation processing by direct compression, dry granulation, or wet granulation. With this in mind, it is easy to understand the popularity of DCP in pharmaceutical tablet formulations. 

Formulations of Tablets Obtained by Direct Compression (Lab Scale)... 

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