Oral drug administration is one of the most popular drug administration pathways, because
of its simplicity, good patient compliance and the absence of adverse effects associated with
other drug delivery pathways. Most of newly-discovered API's are poorly water-soluble,
which means that oral drug administration is not always possible. One of the approaches to
improving water-solubility and the bioavailability of API's is the use of lipid based drug
delivery systems, out of which self-microemulsifying drug delivery systems (SMEDDS) are
becoming increasingly more popular. These systems have better stability and further
improve bioavailability.
The purpose of our work was to study the effect of hypromellose binders on the
transformation of liquid SMEDDS into solid dosage form by wet granulation method. For
the wet granulation we used hypromelloses Pharmacoat® 603, Pharmacoat® 615 and
MethocelTM K100 Premium LV as binders, Syloid® 244 FP as the carrier and carvedilol as
the model API. The goal was to produce tablets with adequate properties from manufactured
granules, while preserving their ability to form microemulsions.
During preliminary manual granulation, we discovered that type and concentration of the
binder does not have an effect on the flow properties of produced granules. We established
that no crystalline carvedilol was present using DSC. During the in vitro dissolution test, the
only granules that did not release all of the model API, were produced with MethocelTM
K100 Premium LV, resulting in our continuing using only the Pharmacoat® binders. Using
high-shear granulation we produced granules with 1,85 % and 7,45 % of binders
Pharmacoat®, from which we produced tablets with adequate mechanical properties that
retained their self-microemulsifying ability. A higher percentage of added hypromellose had
a positive effect on the speed of liberation of the API. The API liberated fastest from tablets
produced with granules with 7,45 % Pharmacoat® 603. The only tablets from which the API
liberated in its entirety were produced from granules with 1,85 % Pharmacoat® 615.
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