Tablets are prepared by compressing uniform volumes of particles or
particle aggregates produced by granulation methods. In the manufacture of
tablet cores means ensuring that they process a suitable mechanical strength to
resist handling without crumbling or breaking. These may be demonstrated by
examining the friability of uncoated tablets and the resistance to crushing.
Chewable tablets are taken to ensure that they are crushed by chewing.
The manufacture of granule for tablet compression may follow one or a
combination of three established methods -
(a) The dry methods of direct compression
(b) Compression granulation
(c) Wet granulation
(a) Direct compression
The vast majority of medicinal agents are rarely so easy to tablet,
however in addition the compression of a single substance may produce tablets
that do not disintegrate. If disintegration is a problem, the components are
needed which in turn may interface with the compressibility of the active
ingredient.
(b) Compression
granulation (Slug process)
This is a valuable technique in situations where the effective dose of a
drug is sensitive to heat moisture or both, which precludes wet granulation.
Many aspirin and vitamin for mutations are prepared for tabletting by
compressing granulation. Compression granulation involves the compaction of a
tablet press or specially designed machinery, followed by milling and screening
prior to find compression into a tablet. When the initial blend of powders is
forced into the dyes of a large capacity tablet press and is compacted by means
of flat faced punches, the compacted masses are called slugs, and the process
is referred to as slugging. The slugs are then screened or milled to produce a
granular form which now flows more uniformly than the original powder mixture.
(c) Wet granulation
This technique uses as same as the two previously discussed granulation
technique. The unique portion of wet granulation process involves the wet
massing of the powder, wet sizing and drying.
