Roller compaction is method of preparing granules for capsules or for tablet formulations. The most common filler–binder excipients used in roller compaction are microcrystalline cellulose (MCC), dibasic calcium phosphate (DCP), and lactose. Studies on the dry granulation of various types of lactose have shown anhydrous lactose to be the best lactose for roller compaction because its brittle nature leads to excellent recompaction properties (1).
The authors investigated the stability of the roller compaction process and the resulting tableting properties of the granules formulated with anhydrous lactose and with combinations of anhydrous lactose and MCC.Materials and methods
The materials consisted of the following: anhydrous lactose (SuperTab 21AN, DMV-Fonterra Excipients, Nörten-Hardenberg, Germany), MCC (Pharmacel 102, DMV-Fonterra Excipients), and magnesium stearate (BUFA, Uitgeest, The Netherlands).
Particle-size distribution. The particle-size distribution (PSD) of the granules was determined with laser diffraction using a Helos system (Sympatec, Clausthal-Zellerfeld, Germany).
Poured and tapped bulk density. Granule poured and tapped bulk densities were determined using ~230 mL of powder in a 250-mL graduated cylinder. Volume and mass were measured before and after 1250 taps.
Tablet compaction. Granule and powder blends were compacted with a rotary press (Rotab-T, Luxner, Berlin, Germany) equipped with 9-mm flat beveled punches. Tablets weighing 250 mg were produced in all cases.
Tablet-crushing strength. The tablet-crushing strength was tested on 10 tablets the day following compaction.
Tablet friability. Friability was tested in accordance with US Pharmacopeia ‹1210 ›.
Tablet weight uniformity. The relative standard deviation (RSD) of the weight of 10 tablets was calculated.