Preparation and Characterization of Meloxicam–Myrj-52 Granules Obtained by Melt Granulation
Various manufacturing techniques can improve a drug's solubility, thus increasing its bioavailability. The authors examined whether melt granulation can enhance drug solubility using meloxicam as the drug substance and myrj-52 as the binder.
Figure 6: Scanning electron microscope images of (a) pure meloxicam at 2×, (b) melt granules of myrj-52 at 4×, and (c) melt
granules of myrj-52 at 20×.
Scanning electron microscopy. Figure 6 shows SEM images of pure meloxicam and the melt granulation with myrj-52. Both photographs of melt granules clearly
show granules with rough surfaces.
Figure 7: Size distribution of meloxicam granules obtained by melt granulation using myrj-52 as a meltable binder.
Production and characterization of granules. Several publications show that process variables such as mixing time, temperature, and amount of binder greatly affect the
characteristics of the granules obtained by melt granulation (4, 5). Therefore, the authors performed preliminary tests to
select the binder concentration and the process parameters using a placebo formulation containing only StarLac and myrj-52.
When good conditions were achieved, 10% (w/w) of StarLac was replaced with meloxicam. Drug-loaded granules were obtained using
the parameters described in the "Methods" section above. Figure 7 shows the granules' size distribution. The amount of fine
powder (< 75 μm) and the amount of big lumps (size > 1400 μm) are less than 1% and 5 %, respectively. This finding confirms
that the parameters were correct. The main fraction was 200–500 μm, and more than 70% of the granules had a size in the range
of 200–750 μm.
Table III: Content of meloxicam in each granule fraction using myrj-52 as a meltable binder.
Table III shows the meloxicam content in each granule fraction. The larger the granule size was, the higher the drug loading
was. In many cases, the drug content is slightly higher (10%) than the theoretical drug content. One explanation could be
that the material lost during granulation was mainly the binder, which was present in the molten form after heating the mixture
and could partially stick to the vessel.
Figure 8: Dissolution profiles of pure meloxicam, melt granulation (MG), physical mixture (PM), and solid dispersion (SD)
of meloxicam in myrj-52.
In vitro dissolution studies. To assess whether the authors had improved the dissolution rate of melt granules containing meloxicam, in vitro dissolution profiles of MG, PM, and SD were compared with those of the pure drug (see Figure 8).