For pharmaceutical tablet production, there are lots of commercial excipients available. All these excipients influence the
drug release of tablet cores in different ways. In this project the influence of Carbopol 71G®, Carbopol 971P®, Fujicalin®,
Neusilin US2®, Neusilin UFL2®, Pemulen TR-1®, Pemulen TR-2®, Sepistab ST 200® and Sepitrap 80® on drug release was
investigated. Tablets were compressed with resveratrol as a model drug using an eccentric press. Tablets containing 2
wt.% of resveratrol which was mixed with a certain amount of excipient, in addition to 1 wt.% of talc, 1 wt.% magnesium
stearate and Ludipress LCE. These products were compared with tablets without any excipients, but with all the other
remaining components of the formulation. Drug release was in vitro investigated in dependence of time, according to
European Pharmacopoeia (Ph. Eur. 2.9.3). It appeared that drug release depends on the qualities of the pharmaceutical
additives. Tablets with Fujicalin® and Sepistab ST 200® exhibit a rapid release and disintegration time, while the other
pharmaceutical additives lead to a delayed release (retardation). Drug release kinetics was described by the mathematical
model of Korsmeyer-Peppas.
Tablets are the best known and most frequently used pharmaceutical
single unit dosage forms. Today more than 40%
of all drugs were consumed in tablet form. Tablets could be
economically produced by a machine in large quantities. More
advantages are the good acceptance of the patients, the possibility
for easy transport and storage. The composition
of different mixed substances allows to create formulations
which releases the drug at the desired location in gastrointestinal
tract (GIT). This means that the right combination
of excipients tends to result in a less drug amount, which is
necessary to achieve the same effects. As a consequence of
this, fewer side effects of drug could be expected. Excipients
are characterized with their fields of functions as base material,
disintegrant, glidant, and lubricant, binder or granulating
agent. Binders are used to enhance cohesion of powder particle
and increase plasticity of tablets. Glidants and lubricants
are flow aids, which improves tablet pressing process. Disintegrants
enhance disintegration of tablets in GIT.
Fujicalin® includes calciumhydrogenphosphate and dicalcium
phosphate anhydrous (DCPA) (Figure 1c). This fillers could be
used for direct compression and to receive hard tablets by using
only small low compression force. It is a porous product
with a low particle size of 115 µm, which is able to adsorb
liquid oily substances. Fujicalin® doesn’t act as disintegrant
but improves the decay of tablets. Because of the fact that
porousity overcomes tablet pressing, water is enabled to penetrate
the tablet faster.
Sepistab ST 200® is a commercial excipient based on a mixture
of native starch and pregelatinized starch, which act as
binder, glidant and disintegrant. Sepitrap 80® is an excipient
comprised from polysorbate 80 (Figure 1d) which is
derived from polyethoxylated sorbitan and oleic acid. In
tablets it works as emulsifier to enhance bioavailability for
poorly water soluble drugs. Neusilin® is based on a totally
synthetic magnesium aluminometasilicate (Figure 1a).
Neusilin US2® is granulate, while Neusilin UFL2® is a powder.
These porous products increase flowability of powder mixtures
and hardness of resulting tablets [10]. Carbopol 71G
NF® and Carbopol 971P NF® are a commercial names for the
same type of polyacrylic acid (Figure 1e). While Carbopol 71G
NF® exhibits a granular physical form, Carbopol 971P NF® is in
powder form. It can be used for direct compressing and leads
to extended drug release of resulting tablets. Pemulen®
is a cross linked copolymer of acrylic acid and a hydrophobic
comonomer with high molecular weight (Figure 1f). Table 1
summarizes all described excipients, with its chemical name.
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